09_safetyengineering

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GE Energy 9.

Safety Engineering

9.1

Page General ........................................................ ....................................................................................9.2 ............................9.2

9.2

Hazardous Hazardous Area Classification Classification ................................................. ................................................. 9.7

9.3

Building and Compartment Compartment Ventilation Design Design....................... ....................... 9.19

9.4

System Vent Design............................................................... Design............................................................... 9.24

9.5

Gas and Chemical Storage and Distribution Systems............ Systems............ 9.28

9.6

Provision Provision and Control Control of Personnel Personnel Access ........................... 9.32

9.7

Design of Emergency Emergency Eyewash Eyewash / Shower Shower Stations Stations ................ 9.45

9.8

Design of Work Areas for Appropriate Appropriate Noise Levels Levels .............. 9.50

9.9

Signs and Pipe Pipe Marking Marking .........................................................9.51 .........................................................9.51

9.10 Design of Lighting and Power Power ................................................ ................................................ 9.56 9.11 Fire Protection ...................................................... ........................................................................ .................. 9.58 9.12 Reference Materials ....................................................... ............................................................... ........ 9.63 9.13 Review Documentation Deliverables...................................... Deliverables...................................... 9.67 9.14 Revision Table............................................... Table........................................................................ ......................... 9.67

GE PROPRIETARY INFORMATION

Safety Engineering ERB/PDBD_Project Design Basis Document

Page 9.1 (05 Nov. 2004)

9.1

General This document details design requirements for personnel safety in the permanent facility. The information provided herein describes good power plant safety engineering practices. practices. Applicable National and Local safety regulations that require additional or specialized equipment or designs beyond those described in the proposal shall be included in the plant design or take precedence as required by law. Similarly, if National or Local safety regulations, or Owner preference requires additional safety studies and services to be performed, they may be included as contract adjustments. In cases where Country/Local practices and codes are determined to be equivalent or more stringent than the practices and codes, cited in the GE Safety Engineering DBD, these Country/Local practices and codes should be referenced within the project specific Safety Summary Report.

9.1.1

Owner’s Responsibility Responsibility The Owner is responsible for providing a site free of hazardous material risks to Personnel prior to project mobilization. This shall be addressed by removal, disposal and/or treatment of pre-existing contaminated materials (e.g. soil, ground water, etc.) at the site.

9.1.2

Design Criteria Documentation Documentation A site specific Safety Engineering Plan shall be submitted to GE Engineering Review Board (ERB) prior to the reviews and shall address all of the elements of this Safety Engineering section of the design basis document. It shall describe how it to meet the requirements of the GE Design Basis Document (DBD). This plan shall also include: •

A tabulated summary of all of the potentially hazardous materials being used in the construction and an d operation of the power plant including: type of hazards, location (use and storage), and required PPE (Personal Protective Equipment) including locations where PPE is required.

•

Requirement that specifications for procurement of the above material shall include the requirement to provide MSDS (Material Safety Data Sheets).


Safety Engineering

GE DESIGN BASIS DOCUMENT

ERB/PDBD_Project Design Basis Document

Page 9.2 (05 Nov. 2004)

9.1

General This document details design requirements for personnel safety in the permanent facility. The information provided herein describes good power plant safety engineering practices. practices. Applicable National and Local safety regulations that require additional or specialized equipment or designs beyond those described in the proposal shall be included in the plant design or take precedence as required by law. Similarly, if National or Local safety regulations, or Owner preference requires additional safety studies and services to be performed, they may be included as contract adjustments. In cases where Country/Local practices and codes are determined to be equivalent or more stringent than the practices and codes, cited in the GE Safety Engineering DBD, these Country/Local practices and codes should be referenced within the project specific Safety Summary Report.

9.1.1

Owner’s Responsibility Responsibility The Owner is responsible for providing a site free of hazardous material risks to Personnel prior to project mobilization. This shall be addressed by removal, disposal and/or treatment of pre-existing contaminated materials (e.g. soil, ground water, etc.) at the site.

9.1.2

Design Criteria Documentation Documentation A site specific Safety Engineering Plan shall be submitted to GE Engineering Review Board (ERB) prior to the reviews and shall address all of the elements of this Safety Engineering section of the design basis document. It shall describe how it to meet the requirements of the GE Design Basis Document (DBD). This plan shall also include: •

A tabulated summary of all of the potentially hazardous materials being used in the construction and an d operation of the power plant including: type of hazards, location (use and storage), and required PPE (Personal Protective Equipment) including locations where PPE is required.

•

Requirement that specifications for procurement of the above material shall include the requirement to provide MSDS (Material Safety Data Sheets).


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Page 9.2 (05 Nov. 2004)

•

•

9.1.2.1

Hazardous Area Classification Map for systems and equipment within the scope of supply. This is required for the Initial Review. Hazardous Area Classification Map for the entire site. It is important important to begin creating this map as soon as there is a tentative site layout since hazardous areas will impact the final site layout. A preliminary site hazardous area map shall be b e provided for the Progress Review.

•

Consolidated map of all ventilation intake and exhaust locations, and vent discharge locations, including elevations.

•

A detailed listing of all codes and standards (including date issued) for supply of equipment and construction of systems and facility, for example: NFPA 101 Life Safety Code, 2000 or ANSI/ASME ANSI/ASME B31.3 Code for Process Piping, 1999 (Not just ANSI, ASME, NFPA).

Project Specific Safety Summary Report Guidance To help GE understand the design philosophy being used to address safety issues associated with the specific project. A safety summary report is useful to provide safety design philosophy information that is not readily called out on the project design documents docu ments (e.g. why a pipe is sized a certain way) to GE. Suggested partner & A/E design relevant aspects for inclusion in the safety engineering design basis document summary report. •

Top-level narratives describing what safety aspects are addressed for the project, including reference to compliance with customer’s technical specification as well as regional, national, and local codes, standards and regulations.

•

Hazardous Area Classification: methodology / assumptions used to create the Hazardous Area Map(s) for the plant, what specific codes, standards, references, internal calculation done by hand or using software, etc.

•

Ventilation Design: for the Heating, Ventilation & Air Conditioning Design (HVAC) describes the basis and methodology for the determination of the ventilation rates in hazardous areas. GE Hazardous Area Maps are based on equivalent outdoor ventilation as defined by NFPA 497 for the United States and projects in other countries subscribing to the NFPA approach or IEC 60079-10 for the European Union and projects in other countries subscribing to the IEC approach.

•

Gas and Chemical Storage and Distribution Systems: asphyxiating & flammable gases design, including discussion related to prevention of


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Page 9.3 (05 Nov. 2004)

above normal concentrations in confined space; plus automatic shut-off provisions in event of emergency or major leak occurrence. •

Gas and Chemical Storage Distribution Systems: storage of petroleum & chemical products design, including discussion related to containment of minor/major spills; plus health & safety considerations from workplace personnel exposure.

•

Gas and Chemical Storage Distribution Systems: fuel gas equipment design, including discussion related to compliance to what specific codes, standards, and references that are used for the design.

•

Gas and Chemical Storage Distribution Systems: compressed gas design, including discussion related to compliance to what specific codes, standards, and references that are used for the design.

•

Provisions and Control of Personnel Access: overall workplace personnel protection provisions, including discussion related to fall heights & protection, safe touch temperatures, security fencing, mechanical & electrical equipment lockout provisions including discussion related to compliance to what specific codes, standards, and references that are used for the design.

•

Provision and Control of Personnel Access: mechanical & electrical guarding provisions, including discussion related to personnel access, workplace maintenance provisions and what specific codes, standards, and references that are used for the design.

•

Design of Emergency Eye Wash / Shower Stations: provide a summary and a map of where all emergency eye wash and shower stations are located throughout the plant, acknowledge that the site is meeting the minimum requirements defined in this document for location and type.

•

Design of Work Areas for Appropriate Noise Levels: near field noise compliance means, plus health & safety considerations from workplace personnel exposure.

•

Design of Lighting and Power: lighting provisions and grounding protection including discussion related to compliance to what specific codes, standards, and references that are used for the design.

•

Fire Protection: design details, including discussion on which plant areas are covered by what type of fire protection / suppression, portable fire extinguishers and locations and rating of fire rated walls; plus integration


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Page 9.4 (05 Nov. 2004)

into hazardous area classification development and plant emergency egress means.

9.1.3

Acronyms and Definitions of Key Terms

9.1.3.1

Acronyms AE - Architect Engineer BOP – Balance of Plant EN – European Normative standard EPC – Entity responsible for Engineering / Procuring / Constructing the plant GT – Gas Turbine GE DBD – General Electric Design Basis Document HRSG – Heat Recovery Steam Generator IEC – International Electrotechnical Commission LEL – Lower Explosive Limit MSDS – Material Safety Data Sheet PPE – Personal Protective Equipment PPM – Parts Per Million ST – Steam Turbine

9.1.3.2

Definitions “Confined or Enclosed Spaces” (extracted from OSHA 1910.146) means any space that: 1. Is large enough and so configured that an employee can enter and perform assigned work; and 2. Has limited or restricted entry or exit (such as tanks, vessels, silos storage bins, hoppers, vaults and pits); and


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Page 9.5 (05 Nov. 2004)

3. Is not designed for continuous employee occupancy “Permit required confined space means a confined space that has one or more of the following characteristics:

1. Contains or has the potential to contain a hazardous atmosphere (e.g. is subject to the accumulation of toxic or flammable contaminants or has an oxygen deficient atmosphere); 2. Contains a material that has the potential for engulfing an entrant (e.g. grain, sawdust, sand); 3. Has an internal configuration; in which an entrant could be trapped or asphyxiated by inwardly converging walls or a floor that slopes downward and tapers to a smaller cross section; or 4. Contains any other recognized serious safety or health hazard.


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Page 9.6 (05 Nov. 2004)

9.2

Hazardous Area Classification The Hazardous Area Classification evaluates all the locations within the power plant and classifies them based on the potential existence of hazardous properties due to the presence of flammable vapors, liquids, or gases, or combustible concentrations of dust or fibers. This classification shall be done in accordance to applicable standards. It is to be cautioned that International International Standards and specific Country Standards may differ from the NFPA Standards followed in the U.S. To create a Hazardous Area Map for US projects p rojects refer to: United States Codes and Standards •

NFPA 70 – National Electrical Code (NEC)

•

NFPA 497 – Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous Haz ardous Locations for Electrical Installations in Chemical Process Areas

•

API 500 – Recommended Practice for Classification of Locations for Electrical Installations At Petroleum Facilities Classified As Class 1, Division 1 and Division 2

•

API 505 – Recommended Practice for Classification of Locations for Electrical Installations At Petroleum Facilities Classified As Zone 0, Zone 1 and Zone 2

To create a Hazardous Area Map for European Union projects refer to: European Codes and Standards •

IEC / EN 60079-10 - Electrical Apparatus for Explosive Atmospheres Classification of Hazardous Areas

•

EN 1127-1 – Explosion prevention and protection

•

94/9/EC, Directive 94/9/EC of the European Parliament and the Council of 23 MARCH 1994 on the Approximation of the Laws of the Member States Concerning Equipment and Protective Systems Intended for the Use in Potentially Explosive Atmospheres. (“ATEX”)


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Page 9.7 (05 Nov. 2004)

•

IP-15 – Institute of Petroleum Area Classification Code for Petroleum Installations (Part 15 of the Institute of Petroleum Model Code of Safe Practice in the Petroleum Industry)

•

IGE SR 25 “Hazardous Classification of Natural Gas Installations”

This area classification shall include associated interconnections and equipment designed by the AE/EPC as well as the GE supplied equipment. All interconnections and equipment with the potential to create a hazard shall be clearly indicated on a comprehensive site map indicating size, location, and elevation of the hazard created. Special consideration shall be made for equipment not provided by the AE/EPC. The considerations for this equipment shall include: 1. Ensuring equipment is rated for use as located (e.g. rated equipment in a hazardous area). 2. Identifying Identifying the hazardous area(s) it may create and ensuring that nonrated equipment (not suitable for hazardous zone) is not located within these identified hazardous areas . 3. Ensuring that inlets to fan ventilated enclosures / compartments cannot “draw” potentially hazardous atmospheres into the enclosure / compartment. NOTE: specific spe cific hazardous haz ardous area dimensions listed in this document are based bas ed on US Standards. This classification should include, as a minimum, any of the items below that are associated with the particular project: •

•

Natural Gas: Gas Turbine Enclosure, Fuel Gas Module/Compartment, Flow Metering Tube, Piping, Filter/Separator, Heater(s), Scrubber, Pressure Reducing Station, Fuel Gas Booster Compressor, HRSG duct burner or auxiliary Boiler. Boiler. Syn-gas (gas derived from coal or residuals): Syn-gas Compartment, Gas Turbine Enclosure, piping, processing equipment.

•

Hydrogen: Generator, generator shaft seals, detraining enlargement vent, Collector Cab/Compartment, hydrogen storage bottles, hydrogen manifold, battery compartment/room, Load Load Compartment.

•

Liquid Fuel Vapor/Mist: Liquid fuel Module, Gas Turbine Enclosure, piping, processing equipment, storage and drains tank(s).


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Page 9.8 (05 Nov. 2004)

•

9.2.1

Lube Oil Vapor/Mist: Mist Eliminator discharge, high-pressure piping/tubing, Accessory Module, Lube Oil Skids with Lift Lift Oil.

•

Mechanical Connections (Non-Welded) in the above systems.

•

Ventilation exhausts or vent discharges for the above systems.

Hazardous Area Philosophy Document A Hazardous Area philosophy document shall be created. It defines the assumptions used to create create the Hazardous Area Map. Each area of the Hazardous Area Map shall have its own assumption criteria that includes, but is not limited to, the following items:

9.2.2

•

Ventilation (e.g. air changes per hour / flow for area)

•

Hazardous gas / liquid vapor (e.g. natural gas, hydrogen)

•

Volume / quantity of release of gas / liquid vapor - this can be during normal modes of operation or during a credible failure scenario

•

Interconnection points (e.g. flanges, welds, compression fittings)

•

All areas should have dimensions in x, y, and z directions and / or defined shape

•

Identification of compartments and components that are to be located in areas outside of Hazardous Areas.

Hazardous Area Map The Hazardous Area Map is a pictorial representation of the hazardous areas as defined in the philosophy documentation (9.2.1). A Hazardous Area is an area with the potential to contain hazardous atmosphere due to the presence of gas / liquid liquid vapor / liquid liquid mist at an ignitable concentration. The Hazardous Area map is required to have the following features: •

Plan and elevation views

•

Each area shall have dimensions in x, y, and z directions and / or defined shape

•

Approximate locations for all field installed pipe vents. The Hazardous Area bubble can either be shown directly on the Hazardous Area Map or it’s dimensions can be tabulated in an attachment.


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Page 9.9 (05 Nov. 2004)

Restricted areas are those areas that must be isolated from potentially hazardous leak sources. Items that are not rated for use in a Hazardous Area must be in a Restricted Area. There shall not be any potential for a Hazardous gas / liquid vapor to exist in a Restricted Area. Examples of Restricted Areas include: •

Compartment air inlets as defined in the Ventilation Design section of this document

•

Areas where non-rated components external to the compartments are located (as a general rule external components are non-rated for use in a Hazardous Area)

•

Any other areas that may reasonably be expected to include a source of ignition (e.g. welding area).

Once the site Hazardous Area Map has been compiled, a review shall be conducted to verify that the equipment located in the hazardous areas is properly rated, and address any non-compliance issues. This may require relocating either equipment that creates a hazard or the non-rated equipment, or upgrading the components affected by the hazards. Examples of different hazardous area map views can be seen in FIGURES 1, 2 and 3.


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Page 9.10 (05 Nov. 2004)

FIGURE 1 – SAMPLE: Isometric View of Accessory Module Hazardous Areas Created During Normal Operation.

FIGURE 2 – SAMPLE: End View of Accessory Module Hazardous Areas Created at Gas Compartment Doors During Ventilation Shut Down


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Page 9.11 (05 Nov. 2004)

FIGURE 3 – SAMPLE: Pipe Vent Termination With High Pressure Flow of Gas Indicating Large Release Source.


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Page 9.12 (05 Nov. 2004)

9.2.3

Design of Equipment Located in Hazardous Areas For equipment located in a hazardous area,

9.2.4

•

Properly locate electrical wiring conduit seal fittings in the conduit runs, per the NEC, and install the manufacturer’s recommended conduit sealer in the fitting

•

Pressurize and vent electrical junction boxes that potentially contain arcing / sparking devices.

Hazard Identification Reference The tables and figures in this section provide a reference for potential areas within the basic designs of a typical power plant that may be deemed hazardous due to the potential for: •

Gas / liquid vapor /liquid mist resulting in a fire/explosion

•

Chemical releases

•

Electrical energy release

Note: not all of the hazards listed above are required to be identified on a site Hazardous Area Map as identified by NFPA or EN 60079-10 (IEC 79-10). Other hazards may need to be considered depending on the applicable codes; for example, hot surfaces.


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Page 9.13 (05 Nov. 2004)

TABLE 1 – Hazard Identification Reference associated with Figures 4, 5, and 6 Chemical

Electrical

Fire / Explosion

1

HRSG Duct Burner System

X

2

Exhaust Enclosure

X

3

GT Turbine Compartment

X

4

Liquid Fuel / Atomizing Air Module

X

5

Gas Valve Module / Compartment

X

6

Fuel Gas Performance & Start-Up Heaters

X

7

Coalescing Filter / Separator

X

8

Fuel Gas Scrubber

X

9

Fuel Gas Pre-Heater

X

10

Filter Separator

X

11

Gas Drain Tank

X

12

GT False Start Drains Tank

X

13

ST HPU Module (not shown)

14

Generator

15

H2 Generator Bottle Storage & Manifold (not shown)

16

Collector Cab

X

17

Collector Enclosure

X

18

Generator Terminal Enclosure (GTE)

X

19

LCI & Excitation Module

X

20

Battery Room(s) – GT (end of the PEECC), ST

21

X X

X X

X

X

X

X

X

ST Electrical Room

X

X

22

Oil Filled Transformers

X

X

23

Switch Yard (not shown)

X

24

Biofouling Chemicals

X

25

Water Treatment Chemicals

X

26

Waste Neutralization Tank

X

27

Fuel Oil Storage Tank

X

28

Fuel Gas Flow Metering Tube

X

FIGURES 4, 5, and 6 are Hazard Identification Maps that identify where the chemical, electrical, and fire / explosion hazards outlined in the above table are located. These figures are representative of a typical Combined Cycle power plant with 2 7FA Gas Turbines and a Steam Turbine, but elements depicted can be applied to any plant.


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Page 9.14 (05 Nov. 2004)

FIGURE 4 – Chemical Hazard Identification Map.


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Page 9.15 (05 Nov. 2004)

FIGURE 5 – Electrical Component Hazard Identification Map.


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Page 9.16 (05 Nov. 2004)

FIGURE 6 – Fire / Explosion Hazard Identification Map.

The locations of potential Fire / Explosion hazards shown in this figure are for reference only.. This figure does not meet the requirements of a Hazardous Area Map as required by either the US NFPA requirements defined in NFPA 70 (NEC) and NFPA 497 or the European Union requirements as defined by ATEX and EN 60079-10.


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Page 9.17 (05 Nov. 2004)

TABLE 2 – Additional Hazard Identification References (Not shown on Figures 4, 5, and 6) Chemical

Electrical

Generator Line Accessory Compartment (GLAC)

X

Generator Neutral Accessory Compartment (GNAC)

X

Switch Gear / Medium Voltage Cell

X

GT Electrical Room / PEECC / TCC / MCC

X

Water Wash Skid

X

Closed Cooling Water System (closed w/ antifreeze)

X

Fuel Gas Shut of Valve and Vent Valve skid (SSOV)


Safety Engineering



Fire / Explosion

X

X

Page 9.18 (05 Nov. 2004)

9.3

Building and Compartment Ventilation Design Building and compartment ventilation is defined as airflow through any building or compartment of a power plant. GE uses a variety of compartment ventilation methods: positive pressure (forced draft), negative pressure (induced draft), and natural/convective. •

Positive pressure occurs when air is pushed into the building or compartment by ventilation fans, creating a higher pressure inside the building or compartment than the ambient pressure.

•

Negative pressure occurs when air is drawn out of the building or compartment by ventilation fans, creating a lower pressure inside of the building or compartment than the ambient pressure.

•

Natural/convective ventilation is created by wind, temperature or gas density differentials that cause the air within the building or compartment to move.

Ventilation air may enter a building or compartment through a variety of inlets. An inlet is any opening into a building or compartment through which air may enter. This includes, but is not limited to, ducts and damper covered openings, doorways, windows that open, and easily opened access panels. The air drawn in through the inlet shall be “safe air,” which does not contain hazards. Safe air is defined as: •

Air with no significant contamination by flammable gasses or vapors that might be harmful to either the equipment or personnel (greater than 25% LEL – Lower Explosive Limit per US-NFPA and EU guidance). Note: US requirement specifies not greater than 10% LEL for personnel exposure.

•

Air that is not significantly above the ambient air temperature.

Ventilation air exits from a building or compartment through exhaust outlet(s). Precautions must be taken when establishing exhaust outlet locations if there are potential hazards in the exhaust air from power plant buildings and compartments. The potential for hazards in exhaust air is dependent upon what is contained within the building or compartment being ventilated. For example: •

Buildings and compartments containing hot equipment, in excess of 60°C (140°F), use the ventilation for cooling purposes; exposure to the elevated


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Page 9.19 (05 Nov. 2004)

temperature of this exhaust air may potentially harm personnel or equipment. Note: this may include steam. •

Buildings or compartments containing parts of a fuel system have the potential for fuel leaks from equipment and the piping system, which may contaminate the ventilation air. The ventilation exhaust of each building or compartment, along with the estimated potential con centration of fuel in the ventilation duct, should be factored into the location/orientation of the building or compartment exhaust outlet(s). The potential fuel sources may include natural gas, syn-gas, liquid fuel vapor/mist, or other alternative fuel source.

•

Buildings or compartments containing high-pressure oil lines have the potential for lube oil mist or vapor to leak into the building or compartment, which may contaminate the ventilation air. The ventilation exhaust of each building or compartment along with the estimated potential concentration of lube oil vapor or mist in the duct should be factored into the location/orientation of the building or compartment exhaust outlet(s).

•

Buildings or compartments containing hydrogen system equipment or DC batteries have the potential for hydrogen to accumulate in the building or compartment, which may contaminate the ventilation air. The ventilation exhaust of each building or compartment along with the estimated potential concentration of hydrogen in the enclosed space should be factored into the location/orientation of the building or compartment exhaust outlet(s).

•

Buildings or compartments containing a CO2 fire suppression system shall not exhaust into an enclosed area that could present a personnel hazard. For indoor installations, the compartment exhaust outlet(s) must be taken outside the main building.

•

Buildings or compartments that serve as maintenance areas where welding, cutting or other fume producing processes take place shall not circulate ventilation exhaust from those maintenance areas into the inlet ventilation of other non-maintenance areas located within the same building.

Turbine-Generators installed within buildings have additional ventilation considerations. Each compartment placed inside of the building needs to be evaluated for the requirements of both its inlet and exhaust air, for example: •

When installing compartments within a building with the associated ventilation fans mounted external to the building, the location of the


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Page 9.20 (05 Nov. 2004)

ventilation fan must be considered carefully with respect to the impact created by this exhaust. (e.g. away from the face of the inlet filter house, personnel access areas, non-rated equipment, etc.). •

When installing compartments within a building with the ventilation fans mounted internal to the building, the location of the outlet duct termination must be considered carefully with respect to the impact created by this exhaust (e.g. away from the face of the inlet filter house, personnel access areas, non-rated equipment, etc.).

•

Compartments with temperatures significantly above ambient should be reviewed for location of the ventilation exhaust outlet to ensure that the air does not exhaust into personnel access areas or other ventilation inlets. Also, impact on the overall building ventilation design must accommodate the additional heat load if this exhaust air is released inside of the building, as some compartments may draw inlet air from inside of the building.

Note: For each project, the specific model of GE gas turbines and their accessories must be reviewed since GE designs vary.

9.3.1

Design for Gas Turbine Compartment Ventilation Exhaust Potential ventilation exhaust hazards include: high temperature and / or the presence of any of the following in the ventilation exhaust: natural gas, syngas, liquid fuel vapor, alternative fuel gas or vapor/mist, lube oil mist or vapor, and CO2. Refer to the project specific GE Gas Turbine Heating & Ventilation Schematic (0426) for design requirements.

9.3.2

Design for Fuel Gas Module (Compartment) Ventilation Exhaust Potential ventilation exhaust hazards include: high-temperature and / or the presence of any of the following in the ventilation exhaust: natural gas, hydraulic oil vapor or mist, and CO2. Refer to the project specific GE Gas Turbine Heating & Ventilation Schematic (0426) for design requirements.

9.3.3

Design for Generator and Collector Cab Ventilation Potential ventilation exhaust hazards include: high-temperature and / or the presence of any of the following in the ventilation exhaust: lube oil vapor or mist and hydrogen (hydrogen generators only). Refer to GE Generator Equipment Documentation for design requirements.


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Page 9.21 (05 Nov. 2004)

For indoor installations of hydrogen generators, the building design must prevent the accumulation of hydrogen either by natural or forced ventilation of ceiling / roof “high points”. The ventilation flow capacity must be sized for the maximum generation rate of hydrogen to preclude gas build-up.

9.3.4

Design for Load Compartment Ventilation (when applicable). Potential exhaust hazards include: high-temperature and /or the presence of hydrogen in the ventilation (when attached to hydrogen generators only). Refer to the project specific GE Gas Turbine Heating & Ventilation Schematic (0426) for design requirements. For indoor installations with hydrogen generators, either the ventilation must be taken outside the building or the building design must prevent the accumulation of hydrogen either by natural or forced ventilation of ceiling / roof “high points”. The ventilation flow capacity must be sized for the maximum generation rate of hydrogen to preclude gas build-up.

9.3.5

Design of Battery Room Ventilation Hydrogen is the only potential exhaust hazard. Hydrogen evolution occurs during battery charging. Battery locations include: the PEECC, steam turbine UPS batteries, and plant facilities batteries. Battery room design must prevent the accumulation of hydrogen by ventilation of ceiling / roof “high points”. Irrespective of the type of ventilation used (convection or forced), flow requirements must be sized for the maximum generation rate of hydrogen. In the case of forced ventilation, the ventilation system shall have a redundant fan system with a method for starting the backup fan if the primary fan should fail. A means for detecting hydrogen accumulation may be required by local codes or standards.

9.3.6

Design for Liquid Fuel/Atomizing Air Compartment Ventilation Potential ventilation exhaust hazards include the presence of any of the following in the ventilation exhaust: liquid fuel vapor / mist and CO2. Refer to the project specific GE Gas Turbine Heating & Ventilation Schematic (0426) for design requirements.


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Page 9.22 (05 Nov. 2004)

9.3.7

Turbine-Generator Building Potential exhaust hazards include: high-temperature, lube oil vapor / mist and hydraulic fluid vapor / mist, fuel gases and liquid fuel vapor / mist (if Gas Turbine is located indoors) and hydrogen (when hydrogen generator is included). The turbine building ventilation system design must consider the inlet and outlet requirements under all potential modes of operation (e.g. minimum allowable number of building fans in operation) and ambient conditions (e.g. cold winter or hot summer temperatures) to ensure that the individual compartments / modules have sufficient ventilation to meet their safe operating requirements. Refer to GE DBD Mechanical Systems Documentation for general design requirements.

9.3.8

Design for Control Room and Office Area Ventilation Control Room and Office Areas are intended for continuous human occupancy. These areas are not designed for hazardous air. Ventilation design must draw air in from a “safe area” outside the building. The air must be free from contaminant levels that could be harmful to human health. . When these areas are part of a building that has the potential to contain hazardous air, there must be a separate ventilation system that draws in air from outside the building, and a slight positive pressure must be maintained inside the office or control room areas.

9.3.9

Design for Exhaust Compartment Ventilation Potential ventilation exhaust hazards include: high temperature and / or the presence of CO2 in the ventilation exhaust. Refer to the project specific GE Gas Turbine Heating & Ventilation Schematic (0426) for design requirements.


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Page 9.23 (05 Nov. 2004)

9.4

System Vent Design Vents are defined as piping or tubing that discharge to the atmosphere. Vent lines can either be isolated by a manual or automatic valve, or be continuously open. Common examples are vent lines connected to return lines, open funnels, drains, tanks, chemical storage tanks, pressure relief valves, gas turbine gas fuel stop-ratio valve cavity (P2) vents, valve stem packing leak-off tubing, hydrogen casing purge, hydrogen scavenging, hydrogen detraining enlargements, and stator cooling water system vents. For all vents, the following must be shown on the P&ID: •

Whether of not the vent is a source of hazardous release

•

What type of release it is

•

Reference to the Hazardous Area documentation for all ve nts that create a hazardous area as defined in the Hazardous Area Classification section of this document.

All hazardous vents shall be routed individually to a safe discharge area based on the potential hazards. Potential areas to avoid are: •

Personnel access ways (e.g. platforms, walkways)

•

Arcing & sparking devices

•

Maintenance areas (e.g. grinding, welding)

•

Designated smoking areas

Note: Information denoted in blue with square brackets [ ] in the below sections refers to the European Union classification for hazardous area designation using Zone and Group, which is different from the US Class, Division, Group system.

9.4.1

Fuel Gas Vents All fuel gas vents shall be individually routed and discharged to a safe area clear of all ventilation inlets, non-rated electrical devices, other potential ignition sources (e.g. hot components, furnaces, etc.), and walkways / personnel access areas. Occasional releases from a small vent of a known volume (e.g. block and bleed vent valve) has a minimum Class I, Div 1, Group D [Zone 1, Group IIA] 1.5 m. (5 ft) spherical radius hazardous area inside of a Class I, Div 2, Group D [Zone 2, Group IIA] 3.0 m (10 ft) spherical radius hazardous area around the vent terminus. Large releases will have a larger


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hazardous area based on the pressure and amount of gas released (e.g. gas compartment/module strainer blow-down connection (FG2)). Pressure Relief lines shall not be “ganged” with each other or any other vent lines. Do not route fuel gas vents to any drains tanks. Note: Follow ALL notes and recommendations found on the GE Fuel Gas System Schematic (0422) for additional information on routing of field run vents, this includes requirements for vent lines to be run individually, recommended vent discharge design per GEK 110743 and hazardous area size/shape at the discharge of the vent.

9.4.2

Purge Vents All purge vents shall be individually routed and discharged to a safe area clear of all ventilation inlets, non-rated electrical devices, other potential ignition sources (e.g. hot components, furnaces, etc.), and walkways / personnel access areas. Occasional releases from a small vent of known volume (e.g. block and bleed vent valve) that are purging fuel gas piping has a minimum Class I, Div 1, Group D [Zone 1, Group IIA] 1.5 m (5 ft) spherical radius hazardous area inside of a Class I, Div 2, Group D [Zone 2, Group IIA] 3.0 m (10 ft) spherical radius hazardous area around the vent terminus. Note: Follow ALL notes and recommendations found on the GE Purge Air System Schematic (0477) for additional information on routing of field run vents, this may include requirements for vent lines to be run separately, recommended vent discharge design per GEK 110743 and hazardous area size/shape at the discharge of the vent.

9.4.3

Hydrogen Vents All Hydrogen vents shall be individually routed to a safe area clear of all ventilation inlets, non-rated electrical devices, other potential ignition sources (e.g. hot components, furnaces, etc.), and walkways / personnel access areas. Occasional releases from a small vent of known volume has a minimum Class I, Div 1, Group B [Zone 1, Group IIC] 1.5 m (5 ft) spherical radius hazardous area inside of a Class I, Div 2, Group B [Zone 2, Group IIC] 3.0 m (10 ft) spherical radius hazardous area around the vent terminus (Note: this guidance is per NFPA 497 and is superceded by any GE provided hazardous area information). Pressure Relief lines shall NOT be “ganged” with each other or any other vent lines. Note: Follow ALL recommendations found on the GE Customer drawings provided for the Generator Accessories (potentially Generator Gas System


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Installation Design Specification 357A2258 and Specification, BDE Vent Piping 358A4741) for additional information on routing of field run vents, this may include requirements for vent lines to be run separately, recommended vent discharge design and hazardous area size/shape at the discharge of the vent.

9.4.4

Lube Oil Vents Lube oil mist and vapor shall be exhausted outside of the Turbine Building. Lube oil mist and vapors should be considered potentially hazardous and this should be taken into account when locating the terminus of the lube oil demister vent. The vent from the lube oil mist eliminator has a minimum Class I, Div 2, Group D [Zone 2, Group IIA] 1.5 m (5 ft) spherical radius hazardous area. Note: depending on the efficiency of the technology used for oil mist elimination, the concentration of oil released in parts per million (ppm) of will vary. This may result in this area not requiring a hazardous classification for oil. Note: Follow ALL notes and recommendations found on the GE Lube Oil System Schematic (Gas Turbine: 0416, and Steam Turbine VD01L) for additional information on routing of field run vents, this may include requirements for vent lines to be run separately and hazardous area size/shape at the discharge of the vent.

9.4.5

Steam Vents All Steam vents shall be routed to an area away from personnel access areas to allow for safe release of the steam. Recommendations include locating silencer and vent discharges away from any personnel access areas including floors, platforms, ladders or stairs at a minimum of 6.0m (20 ft) horizontally and 3.0 m (10 ft) vertically and situated in such a manner that the vents do not direct steam towards stairs, ladders, walkways, platforms, maintenance areas, and/or heat detection devices.

9.4.6

Liquid Fuel Vents All liquid fuel oil vents and open funnels shall be routed to a safe area clear of all ventilation inlets, non-rated electrical devices, other potential ignition sources (e.g. hot components, furnaces, etc.), and walkways / personnel access areas. The vent from a liquid fuel oil storage / drains tank has a minimum Class I, Div 2, Group D [Zone 2, Group IIA] 0.5 m (0.5 ft) spherical radius hazardous area. Note: Depending on the design of the piping to the liquid


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fuel “False Start Drain Tank”, this area can be larger based on the fail open properties of the GE inline drain valves, which may allow the drain line to be pressurized during GT operation.


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9.5

Gas and Chemical Storage and Distribution Systems These sections address design requirements for chemical storage areas and compressed gas storage areas. This section does not cover design standards for bulk fuel storage; this is covered in the GE DBD Mechanical Systems Documentation. Typical chemicals that need to be addressed include aqueous ammonia, anhydrous ammonia, anionic and cationic resins, ethylene glycol, phosphate ester (a.k.a. “Fyrquel”), fire suppression foam, propylene glycol, sodium hypochloride, sodium hydroxide, sodium sulfite/sulfate, sulfuric acid, and various water treatment chemicals. Compressed gases, which need to be considered typically include: Nitrogen, Hydrogen, and Carbon Dioxide (CO2). Storage areas for chemicals and compressed gases must be provided with appropriate signs. Ventilation of chemical storage areas shall be in accordance with OSHA 29 CFR 1910, NFPA, Uniform Fire Code and / or applicable local requirements. The location of chemical storage areas shall be shown on the appropriate drawings including the General Arrangement, Plot Plan, and, for all areas containing flammable/explosive liquids or gases, on the Hazardous Area Map.

9.5.1

Storage and Distribution of Gases Compressed gas systems for power plants in general fit into the following gas categories and uses: •

Carbon Dioxide – Generator purge and Fire Sup pression

•

Compressed Air – Instrument and Service air

•

Gas Fuel – Fuel for Gas Turbine, auxboiler and / or HRSG supplemental firing

•

Hydrogen – Generator fill and makeup for cooling

•

Nitrogen – HRSG / BOP equipment blanketing and various system purges

These systems will be under high pressure and require careful considerations during design, construction and operation. The systems and components shall be designed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII and ASME Power Piping Code 31.1. For European Community Countries the local pressure code (or already mentioned ASME Code), 97/23/EC, the Pressure Equipment Directive (PED) and 87/404/EEC Simple Pressure Vessels shall apply. Additionally all systems shall address container GE PROPRIETARY INFORMATION

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specifications; safety relief devices; design of piping, tubing and fittings; ventilation; and heating. Systems shall be tested and proved to be tight at maximum operating pressure. Facilities design shall comply with OSHA 1910 Subpart M. Non-US projects shall conform to either the US Codes or the national codes and standards specified by that country per contract requirements. Proper ventilation is required for processing and storage areas to mitigate any combustion and/or asphyxiation potential. Each one of these systems may contain the following: •

High pressure gas storage cylinders

•

High pressure safety relief devices

•

Gas pressure control valves

•

Compressors

•

Extensive runs of interconnecting piping

•

Storage and handling facilities

•

Gas venting requirement

In general equipment and cylinders should be protected against mechanical damage. Racks should be provided or other means to hold them securely. Full bottles should be kept separately from empty bottles. Caution signs should address depressurizing systems before disassembly. There should be local gauges for the technician to verify depressurization of the system. Cylinders should be located where they will not be exposed to excessive heat. Outdoor installations should include a roof for solar radiation protection. Bulk storage facilities should be located in the plant yard away from the main structure. Limited numbers of cylinders are acceptable in main building areas. Safety shutoff valves between bulk hydrogen storage facilities and the regulating valve manifold assembly is recommended per NFPA 850, paragraph 5-7.1. GE specification 357A2258, Generator gas System Design Specification, provides guidelines for the design and installation of CO2 and Hydrogen gas supply systems for Generator Applications. Carbon dioxide (CO2), Hydrogen (H2), and Nitrogen (N2) shall be stored in an outside area, inside an enclosure with forced or otherwise well ventilation, or inside an enclosure that precludes the unrestricted entrance of personnel. Enclosed compressed gas storage areas shall be designed to address exposure to potentially hazardous or asphyxiating atmospheres through adequate forced GE PROPRIETARY INFORMATION

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ventilation, gas monitoring and warning systems, or a design that precludes entrance into the gas storage area. Compressed gas storage areas shall be provided with means of securing cylinders. CO2 used for generator purge gas must be stored indoors or in a compartment that maintains a temperature above 10°C (50°F). Refer to GE Generator Station Designers Handbook, C411 Document for specific project requirements. If unventilated, this compartment should be sized to store the CO2 bottles only and preclude the entry of personnel. Refer to GE DBD Mechanical System Description for design requirements of storage area. Hydrogen storage enclosures shall be well ventilated enclosure, as defined per NFPA 497 for hydrogen storage, is one that has any 3 of the possible 5 sides (4 walls and roof) open, that arrangement allows for ventilation equivalent to the equipment being outdoors. CO2 storage used for Fire Suppression systems shall have signs / monitoring of any pits into which the CO2 can settle that meet the recommendations of NFPA 12.

9.5.2

Design Considerations for Gas Fuel Conditioning Equipment The design of an outdoor installation shall include a risk assessment based on the probability of a gas leak and the possible consequences to personnel safety and equipment safety (e.g. “Classification of Hazardous Locations” published by Institution of Chemical Engineers Rugby, Warwickshire England 1990 authored by AW Cox, FP Lees, and ML Ang or British Standard IGE SR 25 “Hazardous Classification of Natural Gas Installations”). All Gas Turbine, Steam Turbine, and Generator equipment is designed to be installed in a safe area regardless of the hazards that equipment may generate. Refer to GE DBD Mechanical System documentation for design requirements.

9.5.3

Chemical Storage A variety of chemicals are used throughout the power plant. Each chemical has specific requirements for safe handling, storage, and use. The main chemicals in use are: •

Acids for demineralizer regeneration, and demineralizer waste neutralization, e.g. sulfuric acid


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•

Caustics for demineralizer regeneration and demineralizer waste neutralization, e.g. sodium hydroxide

•

Biocides for circulating water system treatment, e.g. sodium hypochlorite

•

Ammonia, phosphates and carbohydrazide for cycle water treatment

Refer to the chemical’s MSDS for details. These requirements shall be taken into consideration when designing various chemical storage areas. Additionally there may be National or Local requirements that will mandate additional requirements be addressed for various chemicals. For example: Ammonia storage in the US must comply with 40 CFR 68: General Guidance for Risk Management Programs. Chemical storage areas shall be provided with secondary adequate containment sized per the specifications in the GE DBD Environmental Engineering Systems Documentation. Materials used for construction of containment areas and associated equipment shall be compatible with the chemicals that will be stored in that area. Separate containment areas shall be designed for incompatible chemicals (i.e. acids and bases). Ventilation shall be provided as a means of controlling excessive temperature build-up in storage areas. To comply with NFPA 497 and local fire codes, specific fire protection measures for storage of combustible and flammable materials shall be addressed. Design specifications for systems including storage and piping which use highly hazardous chemicals (as defined by 29 CFR 1910.119 Appendix A, or other appropriate national standards) - shall include safety measures such as interlocks, detection systems, and suppression systems. Additional requirements may apply to the use of highly hazardous chemicals.


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9.6

Provision and Control of Personnel Access 9.6.1

Provision of Access to Work and Maintenance Areas Safe access and working platforms shall be provided for all work and maintenance areas. A stairway or ladder must be provided at all worker points of access where there is a break in elevation of 0.5 m (19 in) or more, and no ramp, runway, embankment, or personnel hoist is provided. Access via stairs or ladders shall be provided for access from one structure level to another where operations necessitate regular travel between levels, and for access to operating platforms for any equipment that requires routine attention. Fixed stairs or ladders shall also be provided where access to elevations occurs daily or during each shift for such purposes as gauging, inspection, regular maintenance, etc.

9.6.2

Design for Provision of Fall Protection Areas and equipment with work/maintenance areas higher than 1.2 m (4 ft) above grade, and for which permanent means of fall protection (e.g. standard railings) are not feasible or are inappropriate, shall have a means of anchoring a personnel fall protection system. Anchors to which personal fall arrest equipment is attached shall be capable of supporting at least 2270 kg (5,000 lbs) per employee attached or meet the specific load requirements for an engineered fall arrestment system under OSHA 29 CFR 1910.66 or other applicable codes / laws. The location of the anchorage point should also consider hazards presented by obstructions in the potential fall path of the employee. OSHA 29 CFR 1910.23.

9.6.3

Design of Platforms, Walkways, Stairways, and Ladders The design of platforms, walkways, ladders, and stairways shall conform to NFPA 101 and, OSHA 29 CFR 1910 for US projects. Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements, such as EN Standards for European Community Countries. Note: requirements for the European Community are provided in blue and square brackets [ ] per the following specifications: Pr-EN 12437-2, 3, 4, EN-131-2, EN 292-1, EN-292-2, EN 3531. These design requirements are to ensure safe and easy access to all components and required access areas in a safe manner by personnel. Refer to the GE DBD Civil / Structural System documentation for design requirements.


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9.6.3.1

Platforms Platforms shall be designed and installed in accordance with 29 CFR 1910.23. Platforms are designed to serve as a working space for persons elevated above the surrounding floor or ground, including balconies or walkways provided for access to machinery and equipment. All platforms where a potential fall of over 1.2 m (4 ft) [EN: 0.5 m.] can occur shall be guarded with a standard guardrail system. Standard guardrail systems shall consist of a top rail, intermediate rail, and posts, and shall have a vertical height of 1.0 m (3.5 ft) [EN: 1.1 m] nominal from upper surface of top rail to floor, platform, runway, or ramp level. The top rail shall be smooth-surfaced throughout the length of the railing. The intermediate rail shall be approximately halfway between the top rail and the floor [EN: 0.5 m], platform, runway, or ramp. The ends of the rails shall not overhang the terminal posts except where such overhang does not constitute a projection hazard. A standard toe-board shall be provided whenever the platform is located above an area where people may pass or where objects may fall. The toe board shall be 100 mm (4 in) nominal in vertical height from its top edge to the level of the floor, platform, runway, or ramp. It shall be securely fastened in place and with not more than 6.4 mm (0.25 in) clearance above floor level. It may be made of any substantial material either solid or with openings not over 25 mm (1 in) in greatest dimension. Pipe railings, posts, top and intermediate railings shall be at least 38 mm (1.5 in) nominal diameter with posts spaced not more than 2.5 m (8 ft) on centers [EN: 1.5 m]. The anchoring of posts and framing of members for railings of all types shall be of such construction that the completed structure shall be capable of withstanding a load of at least 90 kgs (200 lbs) applied in any direction at any point on the top rail [EN: Note: Testing of Guard Rails: Horizontal deflection of handrail shall not exceed 30 mm when loaded for a minute with a force equal of 300 N times the distance in meters between the stanchions. The measurement must be done at the junction point between stanchions and the handrail and repeated halfway between the posts]. Walking surfaces shall be nominally level. The slope of a walking surface in the direction of travel shall not exceed 1 to 20 (1:20) unless the ramp requirements of NFPA 101 are met. The slope perpendicular to the direction of travel shall not exceed 1 to 48 (1:48). Abrupt changes in elevation of walking surfaces shall not exceed 6.4 mm (0.25 in) [EN 4 mm]. Changes in elevation exceeding 6.4 mm (0.25 in), but not exceeding 13 mm (0.5 in), shall


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be beveled 1 to 2, (27 degrees). Changes in elevation exceeding 13 mm (0.5 in) shall be considered a change in level. Where the elevation difference exceeds 0.5 m (21 in), changes in level in the means of egress shall be achieved either by a ramp or a stair. Minimum ceiling height or height to the next platform or walkway level shall be 2.3 m (7.4 ft) above the platform level. [EN: The minimum headroom over platforms and gangways shall be 2.1 m] There shall be no projections from the ceiling or the next platform or walkway that are less than 2.0 m (6.75 ft) from the floor or platform level.

9.6.3.2

Stairways Stairways and stairway railings shall be designed and installed in accordance with 29 CFR 1910.23. All treads shall be reasonably slip-resistant and the nosing shall be of non-slip finish. Welded bar grating treads without nosing are acceptable providing the leading edge can be readily identified by personnel descending the stairway and provided the tread is serrated or is of definite non-slip design. Rise height and tread depth shall be uniform throughout any flight of stairs including any foundation structure used as one or more treads of the stairs. Stair width shall be at a minimum 0.56 m (22 in). All stairway landings and platforms shall be no less than the width of the stairway and a minimum of 30" in length measured in the direction of travel. Stairway landings and platforms shall be designed and constructed to be reasonably slip-resistant. Stairway platforms shall be no less than the width of a stairway and a minimum of 0.76 m (30 in) [EN: 0.8 m] in length measured in the direction of travel. All open sides of stairs and stairway platforms shall be fitted with standard guardrail systems as described in the Platform section above. Vertical clearance above any stair tread to an overhead obstruction shall be at least 2 m (6.67 ft) [EN: 2.3 m] measured from the leading edge of the tread.

9.6.3.3

Fixed Ladders Fixed Ladders shall be designed and installed in accordance with 29 CFR 1910.27. When ladders are used to ascend to heights exceeding 6.1 m (20 ft) (except on chimneys), landing platforms shall be provided not more than 9.1 m (30 ft) apart. Where there is no cage, well, or ladder safety device provided, landing


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platforms shall be provided for each 6.1 m (20 ft) of height. Each ladder section shall be offset from adjacent sections. Where installation conditions (even for a short, unbroken length) require that adjacent sections be offset, landing platforms shall be provided at each offset. [EN: When a fixed ladder exceeds 10 m. it shall be provided with a rest platform. Platforms shall be provided not more than 6 m. apart. Recommended intermediate platform length is 0.7 m] All rungs shall have a minimum diameter of 19 mm (0.75 in) for metal ladders. The distance between rungs, cleats, and steps shall not exceed 0.3 m (12 in) [EN: between 0.25 and 0.3 m] and shall be uniform throughout the length of the ladder. The minimum clear length of rungs or cleats shall be 0.4 m (16 in) [EN: between 0.4 and 0.6 m]. The rungs of an individual-rung ladder shall be designed so that the foot cannot slide off the end "Climbing side." On fixed ladders, the perpendicular distance from the centerline of the rungs to the nearest permanent object on the climbing side of the ladder shall be 0.91 m (3 ft) for a pitch of 76 degrees, and 0.76 m (30 in) for a pitch of 90 degrees. [EN: 0.65 m in front “Climbing Side”, 0.2 m back (0.15 m in case of discontinuous objects)]. The distance from the centerline to the nearest permanent object in back of the ladder shall not be less than 0.18 m (7 in) except when unavoidable obstructions are present. The clearance in back of each rung shall not be less than 0.1 m (4 in).

FIGURE 7 – Rail Ladder with Bar Steel Rails and Round Steel Rungs (from 29 CFR 1910.27, Figure D)


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The step across distance from the nearest edge of the ladder to the nearest edge of equipment or structure shall not be more than 0.30 m (12 in). Protection against the risk of falling through ladder openings shall be provided by a hatch cover or by guardrails in combination with a swing gate (Note: chains are not sufficient to meet this requirement). If gates are utilized, they shall provide both top and mid rail protection. The hatch cover shall move upwards or horizontally and close automatically (e.g. by spring or gravity) not hindering the passage of the user. Counterweighted hatch covers shall open a minimum of 60 degrees from the horizontal. There shall be no protruding potential hazards within 0.61 m (24 in) of the centerline of rungs or cleats. The relationship of a fixed ladder to an acceptable counterweighted hatch cover is illustrated in FIGURE 8. [EN: Exit in the platform; Trap doors: Protection against the risk of falling through such an opening shall be provided by a trap door or by guard-rails in combination with gate. The trap door shall move upwards or horizontally and close automatically (e.g. by spring or gravity) not hindering the passage of the user.]

FIGURE 8 - Relationship of Fixed Ladder to a Safe Access Hatch (29 CFR -


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9.6.3.4

Ladder Cages or Wells Ladders, cages, and wells shall be designed and installed in accordance with 29 CFR 1910.27. All fixed ladders of more than 3.7 m (12 ft) shall be provided with cages. [EN: ladders of more than 3 m or the distance from the center of the ladder to the unprotected side of a platform (or similar) is less than 3 m, then an antifall device (such as a safety cage or a guided type fall arrester on rigid line) shall be provided]. Cages shall extend a minimum of 1.1m (3.5 ft) above the top of landing [EN: 1.1 m], unless other acceptable protection is provided. Cages shall extend down the ladder to a point not less than 2.1 m (7 ft) nor more than 2.4 m (8 ft) above the base of the ladder [EN: between 2.5 and 3 m], with bottom flared not less than 0.1 m (4 in), or portion of cage opposite ladder shall be carried to the base. Ladder cages shall have a clear width of at least 0.38 m (15 in) measured each way from the centerline of the ladder [EN: Cage diameter shall be between 0.7 and 0.8 m]. Smooth-walled wells shall be a minimum of 0.7 m (27 in) from the centerline of rungs to the well wall on the climbing side of the ladder. Where other obstructions on the climbing side of the ladder exist, there shall be a minimum of 0.8 m (30 in) from the centerline of the rungs. The spacing between vertical bars on the cage shall not exceed 0.24 m (9.5 in). [EN: The spacing of safety cages shall be designed so that the empty spaces 2 are not more than 0.42 m whereby the horizontal width of these space shall not exceed 0.3 m]. When ladders provide access to landings that measure 1.2 m (48 in) or less from the ladder rungs to the platforms guardrails, special means shall be used to prevent personnel from falling over the guardrail. (See FIGURE 9)


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FIGURE 9 – Special Means for Guarding Ladders Ending on Platforms (29 CFR 1910.27 Figure D-9)

9.6.4

Emergency Egress All buildings and structures designed for human occupancy shall be provided with exits sufficient to permit the prompt escape of occupants in case of fire or other emergency. Every building or structure shall be provided with exits of the kind, number, location, and capacity appropriate to the individual building or structure, with due regard to the character of the occupancy, the number of persons exposed, the fire protection available, and the height and type of construction of the building or structure, to afford all occupants convenient facilities for escape. The design of exits and other safeguards shall be such that reliance for safety to life in case of fire or other emergency will not depend solely on any single safeguard. Additional safeguards shall be provided for life safety in case any single safeguard is ineffective due to a human or mechanical failure. Exits shall be arranged and maintained to provide free and unobstructed egress from all parts of the occupied building or structure at all times. Every building or structure, section, or area meant for human occupancy shall have at least two means of egress remote from each other and arranged to minimize any


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possibility that any one fire or other emergency condition may block both. Exits and means of egress shall comply with the requirements of 29 CFR 1910.37 for US projects. Under US code, a single means of egress is permitted for “Special Purpose” industrial occupancies from a story of section in low or ordinary hazard industrial occupancies (e.g. the interior of a GE or fuel handling enclosure is a “high hazard” area) where the distance to the exit does not exceed 15 m (50 ft). Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements, for European Community Countries IEC 60364.

9.6.5

Access and Working Space around Power Generation Equipment Sufficient access and working space shall be provided and maintained around electric equipment to permit safe operation and maintenance of such equipment in accordance with 29 CFR 1910.269. Note: Guidelines for the dimensions of access and working space around electric equipment in generating stations are contained in American National Standard - National Electrical Safety Code, ANSI C2-1987 and in NFPA 70 – National Electrical Code.

9.6.6

Access, Limiting Access, and Providing Sufficient Work Space Around High and Low Voltage Areas Note: The below information is extracted from NFPA 70 – National Electrical Code. This information shall be used for US projects. Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements. For European Community IEC 60364 is to be utilized.

9.6.6.1

Low Voltage (< 600 V) At least one entrance of sufficient area shall be provided to gain access to the working space around electrically energized equipment. For equipment rated 1200 amps or more, and over 1.8 m (6 ft) wide, that contain over current devices, switching devices, or control devices, there shall be one entrance to the required working space not less than 0.6 m (24 in) wide and 2.0 m (6.5 ft) high at each end of the working space. Any doors shall open in the direction of egress and be equipped with panic bars, pressure plates, or other devices that are normally latched but open under simple pressure. A single entrance shall be permitted if :


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a) the location permits a continuous and unobstructed way of exit travel (e.g. away from the equipment), or b) the depth of the workspace is twice that shown in TABLE 3 and the distance from the entrance to the nearest edge of the equipment is not less that shown in Table 3 for the voltage and condition applicable to the equipment. The minimum headroom of working spaces around service equipment, switchboards, panel-boards, or motor control centers shall be 2.0 m (6.5 ft). Where the electrical equipment exceeds 2.0 m (6.5 ft) in height, the minimum headroom shall not be less than the height of the equipment. Live parts of electric equipment operating at 50 volts or more shall be guarded against accidental contact. Acceptable guards include approved enclosures (e.g. “NEMA” enclosures); limited access rooms or vaults; suitable permanent, substantial partitions or screens with limited access; location on a gallery, balcony, or platform elevated and restricted so as to exclude unauthorized personnel; or an elevation of more than 2.5 m (8 ft) above the floor or other working surface. The working space for equipment operating at 600 volts nominal, or less to ground, and likely to require examination, adjustment, servicing, or maintenance while energized may not be less than indicated in TABLE 3. The workspace shall be adequate to permit at least a 90-degree opening of doors or hinged panels. In addition to the dimensions shown in TABLE 3, the working space in front of electrical equipment shall be the width of the equipment or 0.76 m (30 in), whichever is greater. Distances shall be measured from the exposed live parts, or from the enclosure or opening if the live parts are enclosed. Working space is not required behind or on the sides of assemblies, such as dead-front switchboards or motor control centers, where all connections or renewable or adjustable parts, such as fuses or switches, are accessible from locations other than the back or sides. Where rear access is required to work on nonelectrical parts on the back of enclosed equipment, a minimum horizontal workspace of 0.76 m (30 in) shall be provided. Switchboards, panelboards, distribution boards, and motor control centers shall be located in dedicated spaces and protected from damage. For indoor locations, this space is equal to the width and depth of the equipment and extends from the floor to a height of 1.8 m (6 ft) above the equipment or to the structural ceiling, whichever is lower. No piping, ducts, leak protection apparatus, or other equipment foreign to the electrical installation shall be located in this zone. GE PROPRIETARY INFORMATION

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TABLE 3 – Working Spaces

Minimum clear distance [mm (ft)] Condition (a)

Condition (b)

0-150

900 mm (3 ft)

900 mm (3 ft)

151-600

900 mm (3 ft)

1 m (3.5 ft)

Nominal voltage to ground

Condition (c)

900 mm (3 ft)) 1.2 m (4 ft)

Conditions (a), (b), and (c), are as follows: (a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating materials. (b) Exposed live parts on one side and grounded parts on the other side. Concrete, brick, or tile walls shall be considered grounded (c) Exposed live parts on both sides of the workspace [not guarded as provided in Condition (a)] with the operator between. Note: this table is taken from the 2005 version of the NEC article 110, table 110.26(a)(1).

9.6.6.2

High Voltage (> 600V) Buildings, rooms, or enclosures containing exposed live parts or exposed conductors operating at over 600 volts, nominal, shall be equipped with a means of preventing access. A wall, screen, or fence shall be used to enclose outdoor electrical installations to deter access by unqualified persons. A fence shall not be less than 2.1 m (7 ft) in height or a combination of 1.8 m (6 ft) or more of fence and a 0.30 m (12in) extension utilizing three or more strands of barbed wire or equivalent. At least one entrance not less than 0.61 m (24 in) wide and 2.0 m (6.5 ft) high shall be provided to give access to the working space about electric equipment. On switchboard and control panels exceeding 1.6 m (6 ft) in width, there shall be one entrance at each end of the equipment. A single entrance shall be permitted if a) the location permits a continuous and unobstructed way of exit travel (e.g. away from the equipment), or


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b) the depth of the workspace is twice that shown in TABLE 4 and the distance from the entrance to the nearest edge of the equipment is not less that shown in TABLE 4 for the voltage and condition applicable to the equipment. Where bare energized parts (at any voltage) or insulated energized parts (above 600 volts) are located adjacent to the entrance, they shall be suitably guarded with a partition, screen, or other barrier against accidental contact. Entrances shall be equipped with a means of locking Sufficient space shall be provided and maintained around electrical equipment to permit safe operation and maintenance of equipment. The minimum headroom and working space width is the same as defined above for systems energized to 600 volts or less. The working space depth shall be as required in TABLE 4. The workspace shall be adequate to permit at least a 90-degree opening of doors or hinged panels. The minimum clear working space in front of electric equipment such as switchboards, control panels, switches, circuit breakers, motor controllers, relays, and similar equipment may not be less than specified in TABLE 4 unless otherwise specified in this section. Distances shall be measured from the exposed live parts or from the enclosure or opening, if the live parts are enclosed. However, working space is not required behind equipment such as dead front switchboards or control assemblies where there are no renewable or adjustable parts (such as fuses or switches) on the back and where all connections are accessible from locations other than the back. Where rear access is required to work on de-energized parts on the back of enclosed equipment, a minimum working space of 0.75 m (30 in) horizontally shall be provided.

TABLE 4 – Minimum Depth of Clear Working Space At Electrical Equipment Minimum Depth of Clear Working Space [mm (ft)]

Nominal voltage to ground

601 to 2,500

Condition (a)

Condition (b)

Condition (c)

900 mm (3 ft)

1.2 m (4 ft)

1.5 m (5 ft)

2,501 to 9,000

1.2 m (4 ft)

1.5 m (5 ft)

1.8 m (6 ft)

9,001 to 25,000

1.5 m (5 ft)

1.8 m (6 ft)

2.8 m (9 ft)

25,001 to 75kV

1.8 m (6 ft)

2.5 m (8 ft)

3.0 m (10 ft)

Above 75kV

2.5 m (8 ft)

3.0 m (10 ft)

3.7 m (12 ft)


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Conditions (a), (b), and (c) are as follows: (a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating materials. (b) Exposed live parts on one side and grounded parts on the other side. Concrete, brick, or tile walls will be considered a s grounded surfaces. (c) Exposed live parts on both sides of the workspace (not guarded as provided in Condition (a)) with the operator between. Note: this table is taken from the 2005 version of the NEC article 110, table 110.34(A). Unguarded live parts located above the working space shall be maintained at elevations not less than specified in TABLE 5. TABLE 5 - Elevation of Unguarded Energized Parts Above Working Space

Nominal voltage between phases

Minimum elevation

601 to 7,500

2.8 m (9 ft)

7,501 to 35,000

2.9 m (9.5 ft)

Over 35kV

2.9 m (9.5 ft) + 9.5 mm (0.37 in) per kV above 35kV.

Note: this table is taken from the 2005 version of the NEC article 110, table 110.34(E)

9.6.7

Design for Safe Touch Temperature of Equipment Maximum surface temperature exceeding 60°C (140°F) per ASTM C 1055 / EN 563 within the power plant shall be guarded, covered, or equipped with a means to prevent accidental contact where personnel are likely to be in close proximity. Alternative protection can be provided to limit personnel access to high temperature areas with standoff systems or other means of preventing access. Refer to GE DBD Mechanical System for design requirements.

9.6.8

Design for appropriate Equipment Guarding Appropriate OSHA compliant guards shall be provided to protect personnel in the power plant from all exposed hazardous surfaces, e.g. rotating, pinch


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point, electrical, and hot temperatures. Refer to OSHA 29 CFR 1910 Subpart O, Machinery and Machine Guarding, for requirements. For projects in Europe, refer to EN-292 The Machinery Directive

9.6.9

Design to Accept Locks (Control of Hazardous Energy Mechanical and Electrical) All energy isolating devices shall be designed to accept a lockout device. An energy-isolating device is capable of being locked out if it has a hasp or other means of attachment to which, or through which, a lock can be affixed, or it has a built-in locking mechanism. Energy isolating devices are defined as any mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: •

A manually operated electrical circuit breaker

•

A disconnect switch

•

A manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently

•

A line valve

•

A block

•

Any similar device used to block or isolate energy

Refer to 29 CFR 1910.147 for design requirements.

9.6.10

Design of Security Fencing Appropriate security fencing shall be provided to restrict access of personnel and the public to potentially hazardous power plant equipment (e.g. switchyards) Refer to GE DBD Civil/Structural System for design requirements of the Security Fencing.


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9.7

Design of Emergency Eyewash / Shower Stations The installation of emergency safety showers and eyewash fountains are required in locations where personnel may contact chemical, biological, or physical agents that require emergency washing facilities. Eyewash and shower equipment for the emergency treatment of the eyes or body of a person exposed to injurious materials shall meet the minimum performance requirements outlined below in the General Requirements for Emergency Eyewashes / Sowers. Emergency eyewash and shower stations shall meet ANSI Z358.1.

9.7.1

General Requirements for Emergency Eyewashes/ Showers • •

Provide in accordance with TABLE 6. Provide eyewash units in any area where there is a potential for the eyes to be exposed to corrosive, irritating, or toxic chemicals, biological hazards, or physical hazards, such as chips or dust from sanding or grinding processes.

•

Connect showers and eyewash units to potable water.

•

Specific water temperature ranges are not specified by regulation. Coordinate with client to determine desired water temperature.

•

Heat tracing shall be provided for outdoor installations with ambient temperatures below 0°C (32°F) to prevent freezing of piping and equipment.

•

Emergency showers and eyewash units shall be accessible within 10 seconds at walking speed from the potential exposure source. Do not locate in rooms or areas with lockable doors.

•

The water supply to shower and/or shower/eyewash combination units shall be controlled by a shutoff valve, which is visible and accessible for shower testing or maintenance personnel in the event of leaking or failed showerhead valves.

Definitions of the different types of emergency eyewash and shower units used in TABLE 6: •

Combination Shower and Eyewash unit* consisting of schedule 80 hot dipped galvanized steel, chrome plated bronze stay open ball valves with


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chrome plated ball, stainless steel actuators and actuation graphics, ABS plastic shower head delivering a minimum 500 mm (20 in) diameter pattern to the target are 1.5 m (5 ft) above standing level, ABS plastic dual stream head with ABS plastic float off covers secured with stainless steel bead chains, self adjusting 0.5 lb/sec (8.0 gpm) eye/face wash regulator assuring a constant, even flow under varying hydraulic conditions. •

Self-contained, Gravity Feed Eyewash unit** with retractable tray protecting eyewash heads, pinch valve design to ensure positive water flow within one second of activation.

•

Eyewash / Body Wash unit*** consisting of piping which is hot dip schedule 80 steel drain/pedestal mount, 12 mm (0.5 in) chrome plated bronze stay open ball valve with chrome plated ball and stainless steel push plate with actuation graphic, ABS plastic dual stream head with ABS float off covers secured with stainless steel bead chain, self adjusting 0.22 lb/sec (3.5 gpm) regulator assuring a constant, even flow under varying hydraulic conditions, ABS plastic bowl or stainless steel bowl.


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TABLE 6 - Emergency Eyewash / Shower System

Equipment Or Location

Chemical(s)

Wash Station

Boiler Chemical Feed

HRSG

Phosphate (pH control, corrosion inhibitor, remove hardness)

Combination Shower and Eyewash *

Selective Catalytic Reduction (SCR) Ammonia Storage Tank and Injection Skid Circulating Cooling Water Chemical Feed

HRSG

19% Aqueous Ammonia

Eyewash / Body Wash ***

Once-through Cooling

Raw Water Chemical Feed (if provided) Condensate Chemical Feed DC Power Supply

Cooling Tower

Intake Structure ST-G Bldg (Surface Condenser Outlet) Raw Water Storage Tank ST-G Bldg GT-G PEECC Batteries

ST-G Bldg Battery Room

Sodium Hypochlorite Combination Shower and Eyewash * Sulfuric Acid, Inhibitor And Sulfite Sodium Hypochlorite Self-contained, Gravity Feed Eyewash ** (Reduce Biological Fouling) Sodium Sulfite Utilize Station for (Reduce Residual Chlorine) Condensate Chemical Feed * Sodium Hypochlorite Eyewash / Body Wash *** Oxygen Scavenger and Combination Shower and Ammonia Eyewash * Battery Electrolyte Personal Eyewash Station (Saline Solution in Bottles) (e.g. Sulfuric Acid) At Battery Compartment Level and Combination Shower and Eyewash Base * of Access Stairs Battery Electrolyte Eyewash / Body Wash (e.g. Sulfuric Acid) ***

Steam Water Sampling and Analysis Panel

ST-G Bldg Ground Floor

Testing Chemicals

Personal Eyewash Station (Saline Solution in Bottles)

Water Testing Laboratory (if provided) ST HPU

ST-G Bldg Ground Floor

Testing Chemicals

Eyewash / Body Wash ***

ST-G Bldg Ground Floor Fuel Oil Storage Area

Fyrquel (Phosphate Ester)

Eyewash / Body Wash *** Self Contained, Gravity Feed Eyewash **

Fuel Oil Treatment (if provided)

Magnesium Sulfinate (Vanadium Fuels), Hytec 580 made by Ethyl

Corporation

Water Treatment

(Lubricity Additive for Light Fuels – Kerosene, Naphtha) Water Treatment Bldg Acid / Caustic storage

Combination Shower and Eyewash *


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9.7.2

Permanent Emergency Showers Emergency showers shall be designed and located in accordance with the following specifications.

9.7.3

•

Provide quick-acting Ball valve for the shower. Shower valve to remain open after the initial pull until manually closed. Locate the face of the showerhead between 2.1 m (6.8 ft) and 2.5 m (8 ft) above the floor.

•

Provide no greater than 0.6 m (23 in) horizontal distance from the center of the showerhead to the activating mechanism.

•

Provide shower unit with one activating mechanism at no higher than 1.7 m (5.75 ft) above the floor. Identify each shower location with a highly visible sign within the area served by the shower.

•

Provide well-lighted area around each shower location.

•

Provide showerhead and pipe sizing with at least 1.26 l/sec (20 gpm) flow, with the operating valve in the open position. Drains are not generally provided for emergency showers. Address design and operational issues with curbs, sloped floors, and dry drain traps for designs incorporating drains. No obstructions, protrusions, or sharp objects shall be located within 0.4 m (16 in) from the center of the spray pattern of the emergency shower unit. Electrical apparatus, telephones, thermostats, or power outlets shall not be located within 0.45 m (18 in) of either side of the emergency shower unit.

Permanent Eyewash Stations Permanent emergency eyewash stations shall be designed and located in accordance with the following specifications. •

Hand-held drench units are acceptable to be used in conjunction with eyewash units, but NOT as a substitute.

•

Locate eyewash units between 0.83 m (33 in) and 1.1 m (3.75 ft) above finish floor level. Provide minimum 0.15 m (6 in) clearance from walls or nearest obstruction.


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•

If available, connect to a tempered water system preset at 21 ± 2.8°C (70 ± 5°F). If tempered water is not available, connect to cold water system.

•

Provide supply line with an uninterruptible supply at 13.6 kg (30 lbs) per square inch of flow pressure. Provide pipe sizing with a minimum of 0.025 l/sec (0.4 gpm) of flushing fluid for 15 minutes for eyewash units.

•

Identify each eyewash location with a highly visible sign within the area served by the eyewash.

•

Nozzles shall be protected from airborne contaminants. The removal of the nozzle protection shall not require a separate motion by the operator when activating the unit. Provide well-lighted area around each eyewash location.

•

9.7.4

•

No obstructions, protrusions, or sharp objects shall be located within 0.4 m (16 in) from the center of the spray pattern of the emergency shower unit.

•

Electrical apparatus, telephones, thermostats, or power outlets shall not be located within 0.45 m (18 in) of either side of the emergency eyewash unit.

•

Portable bottle eyewash units are not an acceptable alternative for these units.

Portable Eyewash Stations Portable Eyewash Stations shall be provided in accordance with ANSI Z358.1. There are a number of different options available. Handheld versions that are permanently fixed in the location are best for temperate climates / indoor applications. For outdoor cold weather applications (below freezing), a portable unit that is easily carried is acceptable. Note: portable squeeze bottle eyewash units are not acceptable.


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9.8

Design of Work Areas for Appropriate Noise Levels Near field noise levels have been designed to limit the potential for permanent hearing loss to plant personnel. The power plant shall meet near field noise levels as stated in the Guarantee Section of the proposal. Areas of high noise within the power plant shall have warning signs with the requirement that personnel noise protection must be worn when entering into the area. Refer to OSHA 29 CFR 1910 Subpart G, Occupational Health and Environmental Control, for requirements or for EN requirements refer to Directive 2000/14/EC Noise Emission in the Environment. Note: 2000/14/EC applies to electrical generation, but only specified max noise level for units less than 400KW. Units greater than 400KW require marking of the sound level only.


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9.9

Signs and Pipe Marking [This section is taken from the GE REAP 072] In addition to signs that may be required by a specific applicable code (e.g. warning signs required under NFPA 12 for spaces protected by a CO2 fire Protection system), signs are required to warn personnel of hazards anytime the existing equipment design, guarding, or other engineering controls cannot adequately mitigate the risk of injury or illness. To objectively determine the level of residual risk posed by equipment, a risk assessment must be performed by the manufacturer per ISO 14121:1999. For example, if the design of a piece of equipment includes rotating part hazards and engineering controls, (such as guards), do not adequately reduce the risk of injury (as determined by a risk assessment), a sign must be used. [Note that hazards that present a lesser risk to personnel may also warrant signs as determined on a case-by-case basis.] In determining the location / need of signs, hazards including, but not limited to, the following shall be considered:

9.9.1

•

Fire

•

Chemical

•

Electrical

•

Temperature Extremes

•

Confined Spaces

Configuration of Signs Safety signs must include the following five standard components: •

A Safety Signal Word appropriate for sign hazard classification

•

A corresponding Safety Alert Symbol

•

Specific Hazard identification

•

A Safety Message panel

•

Appropriate Safety Symbol/Pictorial

These components must be arranged in such a way the Safety Signal Word and Safety Alert Symbol appear in a rectangular band at the top of the sign, GE PROPRIETARY INFORMATION

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the Specific Hazard and Safety Message on the lower-right portion, and Safety Symbol/Pictorial in a square panel on the lower left as depicted in FIGURE 10. FIGURE 11 lists the Safety Signal Words and corresponding Safety Alert Symbols, and defines when each combination shall be used.

FIGURE 10 Standard Components of Safety Signs and Their Configuration


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FIGURE 11 Guidelines for Use of Safety Signal Words and alert Symbols Safety Signal Word

DANGER

Safety Alert Symbol

Definition

Example

!DANGER indicates an imminently

!DANGER -

hazardous situation, which, if not

High Voltage

avoided will result in death or serious injury .

WARNING

!WARNING indicates a potentially

!WARNING -


Rotating Parts

avoided, could result in death or serious injury .

CAUTION

!CAUTION indicates a potentially

!CAUTION -


Hot Surfaces

avoided, may result in minor or moderate injury.

CAUTION

CAUTION used without the safety

CAUTION - Do

alert symbol indicates a potentially

Not Operate


Without Filter

avoided, may result in equipment property damage, but not

personnel injury.

9.9.2

Element Installed

Colors All colors used to create safety signs must conform to ANSI Z535.1-1998. The background color for the upper portion of the sign including the Safety Signal Word and Alert Symbol must be Safety Black. The background for the lower portion of the sign including the Specific Hazard, Safety Message, and Safety Symbol shall be Safety White. The Safety Signal Word “DANGER” and its corresponding Safety Alert Symbol shall appear in Safety White over a Safety Red band. The Safety Signal Word “WARNING” and its corresponding Safety Alert Symbol must appear in Safety Black over a Safety Orange band. The Safety Signal word “CAUTION” and its corresponding


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Safety Alert Symbol must appear in Safety Black over a Safety Yellow band. The Specific Hazard and Safety Message must appear in Safety Black. Safety Symbols/Pictorials may appear in any of the following colors individually or in combination: Safety Red, Safety Yellow, an d/or Safety Black.

9.9.3

Size The size of the lettering and symbols on safety signs are determined by the length of the message and the distance from which the message / symbol must be easily read. Lettering and symbols must be large enough so that a person with normal vision (including corrected vision) is able to read the sign at a safe viewing distance from the hazard. For this reason, text messages in the Specific Hazard identification and Safety Message portions of the sign should be concise. Per ANSI Z535.4-1998 B3.2.12, multiply the minimum safe viewing distance (in feet) by 0.084 inches to determine the appropriate letter height (in inches). No lettering on safety signs shall be smaller than 2 mm (0.08 in) in height.

9.9.4

Safety Symbols/Pictorials Whenever possible, Safety Symbols/Pictorials shall be used to convey the nature of the hazard, the consequences of not avoiding the hazard, and/or evasive/avoidance actions to be taken. Symbols must be compatible with the word messages on the sign. Only symbols/pictorials that have been designed in accordance with ANSI Z535.3-1998 (6), and validated for recognition per ANSI Z535.3-1998 (7) may be used.

9.9.5

Materials, Mounting, and Placement Safety signs shall be constructed of a material that will provide color stability and legibility under adverse environmental conditions for the duration of the expected life of the product (30 years for most power generation equipment and accessories). Mounting systems must be adequate to keep signs attached for the same time period and make it difficult for signs to be removed. Signs shall be placed in the immediate vicinity of the hazard in such a way that maximizes their visibility. The placement must provide a safe viewing distance, which permits a reasonable hazard avoidance reaction time. Additionally, signs must be protected from foreseeable damage, fading, abrasion, ultra-violet light, chemicals, dirt, and weathering. In general the number of separate signs placed in a single location should be limited to reduce the potential for overwhelming or confusing the operator. Whenever possible, limit the number of signs on a given panel or door to three or less.


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9.9.6

Multi-Lingual Signs The AE / EPC shall inquire if multi-lingual safety signs are required. This decision will be based upon: •

Local codes and regulations

•

Customer request

•

Contract conditions

If it is determined that multi-lingual signs are necessary, signs with 3 sections set horizontally shall be provided as depicted in FIGURE 12. The center section will contain the Safety Symbols/Pictorials. The left section will contain the Safety Signal Word, Safety Alert Symbol, Specific Hazard, and Safety Message written in the local or other appropriate language. The right section will contain the Safety Signal Word, Safety Alert Symbol, Specific Hazard, and Safety Message written in English.

FIGURE 12 Standard Components of Safety Signs and Their Configuration for Multi-Lingual Signs


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9.10 Design of Lighting and Power 9.10.1

Design for Plant Exterior and Interior Lighting The plant exterior and interior lighting shall be designed to provide adequate lighting for access to equipment during operation. Refer to GE DBD Electrical System document for design requirements. Additional information is available in ANSI/IES (Illuminating Engineering Society) RP-7, Practice for Industrial Lighting and the IES Lighting Handbook for US projects. NonUS projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements, for European Community Countries IEC 60364 & IEC 60061. All means of access, walkways leading to working areas, and the working areas themselves shall be adequately illuminated. Refer to the American National Standard A11.1-1965, R1970, Practice for Industrial Lighting, for recommended values of illumination for US projects. Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements. For European Community Countries, refer to IEC 60364 & IEC 60061.

9.10.2

Design for Emergency Power Emergency Power shall be of sufficient DC power to bring the power plant down to a safe condition upon loss of normal AC power and to supply power to the DC emergency lighting system and the turbine’s DC emergency motors. Refer to NFPA 101 for US projects. Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements. European Community Countries shall refer to IEC 60364 & IEC 60061 for specific requirements on how long the lights must work. Refer to GE DBD Electrical System document for design requirements. Note: The ‘rapid restart’ or AC Shutdown is detailed in the GE DBD Electrical Systems document.

9.10.3

Design for Emergency Lighting Emergency Lighting systems shall be sized to provide sufficient emergency lighting to allow for plant personnel to safely leave operational areas. NFPA 101 Life Safety Code requires a minimum 1-foot candle for safe egress from these areas within the power plant during loss of AC power, and it also requires a minimum 0.2-foot candle with the loss of a single emergency


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illumination unit. Refer to NFPA 101 for US projects, Non-US projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements. European Community Countries shall refer to IEC 60364 & IEC 60061 for specific requirements on how long the lights must work. Refer to GE DBD Electrical System document for design requirements.

9.10.4

Design of Protective Grounding Systems Protective grounding equipment shall be capable of conducting the maximum fault current that could flow at the point of grounding for the time necessary to clear the fault. This equipment shall have an ampacity greater than or equal to that of No. 2 AWG copper. Protective grounds shall have an impedance low enough to cause immediate operation of protective devices in case of accidental energizing of the lines or equipment. All non-current carrying metallic objects such as fencing, building steel, equipment enclosure, pullboxes, equipment support structures and other frame work, shielded cable sheaths, metal conduit, pipe, etc shall be grounded to a common earth potential to minimize the effects of shock hazards. Note: Guidelines for protective grounding equipment are contained in American Society for Testing and Materials Standard Specifications for Temporary Grounding Systems to be used on De-Energized Electric Power Lines and Equipment, ASTM F855-1990 and 29 CFR 1910.269(n) for US projects. NonUS projects shall conform to either the US codes or the national codes and standards specified by that country per the contract requirements. , For European Community Countries, refer to IEC 60364 & IEC 60061.


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9.11 Fire Protection Note: The design of the Fire Protection System shall meet the various requirements defined by NFPA or other national codes and standards specified by another country per the contract requirements. Additionally all insurance company requirements in excess of any of these codes shall be met per the contract requirements.

9.11.1

Design of Fire Detection Systems The number, spacing and location of fire detectors shall be based upon design data obtained from field experience, testing, engineering surveys, the manufacturer's recommendations, or a recognized testing laboratory listing. Custom fire detection systems should be designed by knowledgeable fire protection or electrical engineers who are familiar with the workplace hazards and conditions. Fire detection systems shall meet the requirements specified in NFPA 72. Fire detectors must be protected by protective coatings, manufactured from non-corrosive materials, or placed in a non-corrosive environment in order to prevent corrosion. Detectors must also be protected from mechanical impact damage, either by suitable cages or metal guards where such hazards are present, or by locating them above or out of contact with materials or equipment that may cause damage. Fire detector supports shall be independent of their attachment to conduit, wires or tubing. •

Fire detection systems installed for the purpose of actuating the fire protection system shall be designed to operate in time to control or extinguish a fire.

•

Fire detection systems installed with the purpose of warning employees to evacuate shall be designed with alarms to provide a warning for emergency action to allow the safe escape of employees.

•

Fire detection systems should be monitored. Electrically operated sensors are typically used to measure air pressure, fluid pressure, or electrical circuit faults and provide effective monitoring capability.


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9.11.2

Alarm Systems In every building or structure of such size, arrangement, or occupancy that a fire may occur, fire alarm facilities shall be provided where necessary to warn occupants of the existence of fire. The alarm must be recognized above ambient noise or light levels in the affected portions of the workplace. Fire alarm shall meet the requirements specified in NFPA 72 .

9.11.3

Design of Fire Suppression Systems Design for Fire Suppression Systems shall be in accordance with NFPA 850 Recommended Practice for Fire Protection for Electrical Generating Plants and High Voltage Direct Current Converter Stations. Fire Suppression Systems shall be designed in accordance with the applicable NFPA requirements for that system NFPA 11

Standard for Low Expansion Foam

NFPA 11A

Standard for Medium and High Expansion Foam

NFPA 12

Standard on Carbon Dioxide Extinguishing Systems

NFPA 13

Standard for the Installation of Sprinkler Systems

NFPA 15

Standard for Water Spray Fixed Systems for Fire Protection

NFPA 16

Standard for the Installation of Foam-Water Sprinkler and Foam Water Spray Systems

NFPA 17

Standard for Dry Chemical Extinguishing Systems

NFPA 230

Standard for the Fire Protection of Storage

NFPA 750

Standard on Water Mist Fire Protection Systems

NFPA 2001

Clean Agent Extinguishing Systems

The selection of an extinguishing agent or a combination of agents shall be based upon a fire risk evaluation (Note: Guidelines for conducting a Fire Risk Evaluation are provided in NFPA 850 Chapter 3) and shall take into account the type of hazard, the effect of the discharge agent on equipment, and health hazards associated with the discharge agent.


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Refer to GE DBD Mechanical System document for design requirements of the Fire Protection Systems(s). The final design of the Fire Suppression System often requires approval from local fire officials. Appropriate instruction and warning signs shall alert personnel to both location of fire protection system and hazards created by the fire protection system.

9.11.3.1

Design of Water Fire Sprinkler Suppression Systems Automatic sprinkler systems shall meet 29 CFR 1910.159 and NFPA 13 standards in effect at the time of installation. All automatic sprinkler designs shall provide the necessary discharge patterns, densities, and water flow characteristics for complete coverage in a particular workplace or zoned subdivision of the workplace. Every automatic sprinkler system shall be provided with at least one automatic water supply capable of providing design water flow for at least 30 minutes. Piping shall be protected against freezing and exterior surface corrosion. All dry sprinkler pipes and fittings shall be designed and installed so that the system may be totally drained. A local water-flow alarm, which sounds an audible signal on the premises upon water flow through the system equal to the flow from a single sprinkler shall be provided. Sprinklers shall be spaced to provide a maximum protection area per sprinkler. Building structural members or building contents should cause a minimum interference to the discharge pattern and be of suitable sensitivity to possible fire hazards. The minimum vertical clearance between sprinklers and material below shall be 0.45 m (18 in.).

9.11.3.2

Design of Fixed Extinguishing Systems Other Than CO2 and Sprinkler Systems Foam and water spray systems shall be designed to be effective in controlling fire in the protected area or on protected equipment. When selecting the type of foam for a specific hazard, the design shall consider the following limitations: •

Some foams are not acceptable for use on fires involving flammable gases and liquefied gases with boiling points below ambient workplace temperatures.


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•

Other foams are not effective when used on fires involving polar solvent liquids.

•

Any agent using water as part of the mixture should not be used on fire involving combustible metals unless it is applied under proper conditions to reduce the temperature of burning metal below the ignition temperature.

•

Do not use chlorobromomethane or carbon tetrachloride as an extinguishing agent.

•

Only those foams that have been tested and accepted for this application by a recognized independent testing laboratory shall be used.

Drainage facilities shall be provided to carry contaminated water or foam overflow away from the employee work areas and egress routes. This drainage system shall be designed such that contaminated water or foam can be collected for treatment or disposal. A distinctive alarm or signaling system capable of being recognized above ambient noise or light levels shall be designed to indicate when the extinguishing system is discharging. Discharge alarms are not required on systems where discharge is immediately recognizable. On total flooding systems the design shall include a pre-discharge employee alarm, which will give employees time to safely exit from the discharge area prior to system discharge. Systems installed in the presence of corrosive atmospheres shall be constructed of non-corrosive material or otherwise protected against corrosion. Systems designed for and installed in areas with climatic extremes shall operate effectively at the expected extreme temperatures. The design shall include at least one manual station for discharge activation of each fixed extinguishing system.

9.11.3.3

Design of CO2 Fire Suppression Systems (Other than the GE provided Gas Turbine System) Systems shall be designed to comply with NFPA 12. Agents used for initial supply and replenishment shall be of the type approved for the system's application. Total flooding gaseous systems are based on the volume of gas, which must be discharged in order to produce a certain designed concentration of gas in an enclosed area. The concentration needed to extinguish a fire depends on


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several factors including the type of fire hazard and the amount of gas expected to leak away from the area during discharge. At times it is necessary to "super-saturate" a work area to provide for expected leakage from the enclosed area. The design shall assure that the designed extinguishing concentration is reached within 30 seconds of initial discharge. A pre-discharge alarm for alerting employees before system discharge shall be provided on carbon dioxide systems with a design concentration of 4 percent or greater. The pre-discharge employee alarm shall provide employees time to safely exit the discharge area prior to system discharge. The time duration between the alarm and the actual discharge shall be determined via live drills from all foreseeable work locations with the protected space.

9.11.4

Design for Fire Extinguishers in Buildings Approved portable fire extinguishers shall be selected and distributed based on the classes of anticipated workplace fires and on the size and degree of hazard, which would affect their use. Fire extinguishers for use on Class A fires shall be distributed so that the travel distance for employees to any extinguisher is 23 m (75 ft) or less. Fire extinguishers for use on Class B fires shall be distributed so that the travel distance from the Class B hazard area to any extinguisher is 15 m (50 ft) or less. Fire extinguishers used for Class C hazards shall be distributed on the basis of the appropriate pattern for the existing Class A o r Class B hazards.

9.11.5

Design for Use of Fire Retardant Materials in Buildings Appropriate use of fire retardant materials shall be used to allow personnel to safely exit the building in case of a fire incident. Refer to GE DBD Civil/Structural System for design requirements. Additional recommendations on design and requirements for fire retardant materials in buildings can be found in NFPA 850.


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9.12 Reference Materials The master list of codes and standards can be found in GE DBD Section 12 – Codes & Standards, which contains the most up to date information.

9.12.1

ANSI – American National Standard Institute ANSI C2 (1987) National Electrical Safety Code, ANSI Z358.1 (1998) Emergency Eyewash and Shower Equipment ANSI Z535.1 (1998) Safety Color Code ANSI Z535.2 (1998) Environmental and Facility Safety Signs ANSI Z535.3 (1998) Criteria for Safety Symbols ANSI Z535.4 (1998) Product Safety Signs and Labels ANSI Z535.5 (1998) Accident Prevention Tags

9.12.2

API – American Petroleum Institute API 500 Recommended Practice For Classification of Locations For Electrical Installations At Petroleum Facilities Classified As Class I, Division 1 and Division 2 API 505 Recommended Practice For Classification of Locations For Electrical Installations At Petroleum Facilities Classified As Zone 0, Zone 1 and Zone 2

9.12.3

ASME – American Society of Mechanical Engineers ASME B31.3 Process Piping ASME PV CODE 8 DIV 1 (2001) Pressure Vessel - Division 1 (Boiler & Pressure Vessel Code, Section VIII)

9.12.4

ASTM - American Society of Testing & Materials ASTM C 1055 (1999) Standard Guide for Heated System Surface Conditions That Produce Contact Burn Injuries


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9.12.5

IEC / EN Harmonized European Standards Directives

87/404/EEC, Directive 87/404/EEC of 25 June 1987 on the harmonization of the laws of the Member States relating to simple pressure vessels 94/9/EC, Directive 94/9/EC of the European Parliament and the Council of 23 MARCH 1994 on the Approximation of the Laws of the Member States Concerning Equipment and Protective Systems Intended for the Use in Potentially Explosive Atmospheres. (“ATEX”) 97/23/EC, Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment (“PED”) 2000/14/EC Noise Emission in the Environment Directive Standards

EN 1050 (1996) Safety of Machinery – Principles for Risk Assessment. Pr-EN 12437-2,3,4 (1996) Permanent Means of Access to Machines and Industrial Plants. EN 131-2 (1993) Ladders – Part 2: Specification for Requirements, Testing, Marking EN 292-1 (1997) Safety of Machinery; Basic Concepts and General Principles for Design; Basic Terminology, Methodology EN 292-2 (1997) Safety of Machinery; Basic Concepts and General Principles for Design; Basic Terminology, Methodology - Part 2. Technical Principles and Specification EN 353-1 (1993) Personal Protective Equipment Against Falls From a: Guided Type Fall Arresters – Part 1: Specification For Guided Type Fall Arresters on a Rigid Anchorage Line EN 563 (1994) Safety of machinery - Temperatures of touchable surfaces Ergonomics data to establish temperature limit values for hot surfaces EN 60079-10 - Electrical Apparatus for Explosive Atmospheres Classification of Hazardous Areas


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IEC 60061 – Lamp Caps and Holders Together with Gauges for the Control of Interchangeability and Safety IEC 60364 - Electrical Installations of Buildings

9.12.6

IES – Illuminating Engineering Society IES RP 7 Industrial Lighting Facilities (2001)

9.12.7

IP – Institute of Petroleum IP-15 – Institute of Petroleum Area Classification Code for Petroleum Installations (Part 15 of the Institute of Petroleum Model Code of Safe Practice in the Petroleum Industry)

9.12.8

ISO – International Standard Organization ISO 3864 (1984) Safety Colours and Safety Signs ISO 7000 (1989) Graphical Symbols for Use on Equipment ISO 14121 (1999) Safety of Machinery – Principles of Risk Assessment

9.12.9

NFPA – National Fire Protection Association NFPA 10 Standard for Portable Fire Extinguishers NFPA 11 Low Expansion Foam Systems NFPA 12 Carbon Dioxide Extinguishing Systems (2000) NFPA 13 Installation of Sprinkler Systems NFPA 14 Standpipe and Hose Systems NFPA 15 Water Spray Fixed Systems NFPA 16 Installation of Foam-Water Sprinkler and Foam-Water Spray Systems NFPA 20 Centrifugal Fire Pump Design NFPA 70 National Electric Code


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NFPA 72 National Fire Alarm Code NFPA 101 Life Safety Code NFPA 214 Water Cooling Towers NFPA 497 Recommended Practice for Classification of Flammable Liquids, Gases, or Vapors and of Hazardous Locations for Electrical Installations in Chemical Process Areas NFPA 750 Standard on Water Mist Fire Protection Systems NFPA 850 Recommended Practice for Fire Protection for Electric Generating Plants and High Voltage Direct Current Converter Stations (2000) NFPA 2001 Clean Agent Extinguishing Systems

9.12.10

OSHA / EPA 29 CFR 1910 Occupational Health and Safety Standards 40 CFR 68 General Guidance for Risk Management Programs EPA home page: www.epa.gov OSHA home page: www.osha.gov

9.12.11

UK Standards “Classification of Hazardous Locations” published by Institute of Chemical Engineers Rugby, Warwickshire England 1993 authored by AW Cox, FP Lees, and ML Ang IGE SR 25 “Hazardous Classification of Natural Gas Installations” British Standards

BS 5378:PT1 (1980) Safety Signs and Colours – Specification for Colour and Design BS 5378:PT2 (1980) Safety Signs and Colours – Specification for Colorimetric and Photometric Properties of Materials


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