Work Sequence for Piping Planning & Design

Work Sequence Piping Planning & Design Expertise

5.6

6

7

Relaxation Of Space Requirements

29

DETAIL PLANT LAYOUT

30

6.1

Plant Elevation

30

6.2

Paving

30

6.3

Classification Of Roads And Accesses

31

6.4

Road

32

6.5

Underground Facility

34

6.6

Top Elevation Of Foundation

34

6.7

Minimum Distance Between Equipment And Road

35

6.8

Structure Layouts

36

MAINTENANCE CONSIDERATION

45

7.1

Classification Of Maintenance Work

45

7.2

Design Of Maintenance Provisions

46

7.3

Detailed Maintenance Considerations

48

8

PIPE ROUTING

52

9

PIPING SYSTEMS DESIGN

53

9.1

Process Piping

53

9.2

Pressure Relief Piping

53

9.3

Instrument Air

54

9.4

Drain Systems

55

9.5

Fire Water System

56

9.6

Utility Stations

57

9.7

Sample Connections

57

9.8

Heat Tracing

58

9.9

Potable Water

58

10

11

9.10 Emergency Shower And Eyewash Fountains

58

EQUIPMENT PIPING DESIGN

59

10.1 Vessel Piping

59

10.2 Heat Exchanger Piping

60

10.3 Pump Piping

62

10.4 Compressor Piping

66

10.5 Fired Equipment Piping

68

10.6 Filter Piping

69

10.7 Storage Tank Piping

69

PIPE SUPPORT DESIGN

70

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1

INTRODUCTION The main purpose piping designer is to supply detailed information in drawing piping form to enable a plant to be built. Prior to making piping drawings such as plan layout, piping key plan and equipment arrangement drawing are prepared. These three drawing are used as the basis for developing the piping drawings. Generally equipment location drawings are developed by senior-level piping designers during the proposal preparation and are taken over by the project team upon award of the contract. From this point on they are revised and updated as part of the normal process of design development. Equipment should be arranged with the piping layout in mind. Equipment locations and relational arrangements should be evaluated during the piping layout design process. Adjustments and occasionally major changes to equipment arrangement are required to solve major piping arrangement problems. Piping system design is dependent on the input from numerous reference sources prior to the start of piping design. Facility design and layout must meet the customer's expectations as well as comply with safety codes, government standards, client specifications, budget, and start-up date. The site area utilized should be determined based on optimizing safety, operability, maintainability and constructability of the plant.

2

GENERAL WORK SEQUENCE FOR PIPING PLANNING & DESIGN

2.1

Gathering and Identify Information Some information requires in completing steps for piping planning and design work are as follow: •

Piping and Instrumentation Diagram P&ID show essential process lines interconnecting process equipment. P&ID indicates required number, types and sizes equipment for plant operation. And P&ID shows type of lines required for plant design. piping designer can be identify type of lines in three categories:

a. Main process flow lines, b. Equipment interconnecting lines c. Feed and Product lines •

Inter Disciplines Info Info from others discipline are required for considerations in completing equipment layout/ Plot Pan and piping routing such as Civil Engineer provides site elevations, soil condition, prevailing wind direction, drainage plan and grade sloping. Electrical engineer provide underground cable plan. And Mechanical Engineer provides equipment dimensions, equipment orientations and other info from suppliers.

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2.2

Grouping Equipments From P&ID, piping designer should be decide blocking area classifications into : - Offsite •

Loading facilities

•

Storage tank facilities

•

Flare stack

- Onsite/Process site •

Gas compression

•

Separation and Process facilities

- Utilities •

Boilers, Air compressors, Nitrogen plant etc.

•

Power generation

•

Shops, Maintenance, and Warehouse

- Offices

2.3

•

Administrative office

•

Electrical switch room

•

Control Room

Allocating Group Area in Plant Layout After complete grouping equipment, piping designer should allocate available plant area into blocking area classifications based on plant layout consideration (summarized in section 4), equipment spacing requirements (summarized in section 5) and maintenance considerations (summarized in section 7).

2.4

State Location and estimate width of pipe rack Use plant layout and process flow diagrams to make a preliminary assessment of which portion of process lines will be located in piperack and which lines will interconnect directly to nozzles on adjacent items of equipment.

2.5

Identify priority lines piping designer should be make rankings or priority lines based on material line types, pressure lines and size lines. Piping makes rankings from expensive alloys down to the less expensive, carbon steel lines. From high pressure lines/ high rating line down to low pressure/ low rating lines. And also from large size lines down to small size lines.

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2.6

Estimate minimum pipe routing and re-adjust for optimal equipment location After identify rankings or priority lines and , piping designer can be estimate minimum pipe routing and re-adjust for optimal equipment location to meet minimum cost targets. piping designer should make sketch equipment elevation and make underground routing based on inter disciplines info.

2.7

Sketch Piping Arrangement Piping arrangement drawing is a detail drawing that show 3D piping configuration to meet process, safety and maintenance requirement based on plant layout space. Major guidelines in Piping arrangement are Simple arrangement, short lining, minimize pressure drop and the lower pumping cost. This can be achieved by closely coordinated overall design and accurate cost comparison between alternative solutions. And also piping designer must be coordinate with stress analysis engineer to meet safety flexibility arrangement.

2.8

Make piping elevation & details Piping designer should also keep coordinating with Piping Stress Engineer to consider the final results whether the pipe systems are safe and unchanging so that the drawing and model can be built as per constructability elevation and details. After having drawing finalized, the Piping Senior Designer should accommodate the information to the Piping Planning & Design to be checked by inter-disciplines. This will be the time where interdiscipline can communicate, re-check and adjust for overall adjustment.

2.9

Extract piping isometric Piping designer can also supervise the PDS team to build a model which finally can be extracted to piping isometric drawings. These isometrics will be used as a base for Piping Material Engineer to take off the materials requirement for construction phase.

2.10 Make Piping support plan & details Piping designer should begin the pipe supports or special pipe supports planning and detailing drawing. Pipe Stress Engineer has decided the final possibility where the supports can be installed in piping systems. This also takes Piping Material into account of predicting the needs of materials to be used in constructing pipe supports. Experiences have proven that most of these piping supports or special pipe supports materials were not taken off so that at the construction phase the delay of piping construction occurred. Piping systems used

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temporary support using existing materials. So the planning of piping supports should be a responsibility of all Piping Team.

3 3.1

OVERALL PLANT LAY-OUT Block Area Arrangement The following are the blocking classifications, which also rank of the hazard from highest to lowest: - Offsite 1. Loading facilities 2. Storage tank facilities 3. Flare stack - Onsite/Process site 1. Gas compression 2. Separation and Process facilities - Utilities 1. Boilers, Air compressors, Nitrogen plant etc. 2. Power generation 3. Shops, Maintenance, and Warehouse - Offices 1. Administrative office 2. Electrical switch room 3. Control Room

The followings are guideline for the arrangement: 1. The

process area shall be located in the most convenient place for process unit

operation 2. The storage area shall be located as far as possible from Utilities and offices, where most of the time attended by personnel. 3. The Utilities shall be located beside the process area for ready supply of utilities. 4. The Offices shall be located at a safe place in the site to protect personnel from hazard. 5. Flare stack shall be located at the end of the site to prevent hazard to personnel.

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3.2 Roadways a. Roads and access ways shall offer easy access for mobile equipment during: •

Construction

•

Maintenance

•

Fire fighting

b. Process units should be provided with fire breaks of at least 6 m approximatelly every 60m by means of access ways or through equipment lay-out consideration.

c. Normally there are two types of road: •

Primary road 6 m width and 7 m height clearance, means for two way traffic lane and heavy large crane, and act as fire break among process units.

•

Secondary road 4-m width and 5 m height clearance means for one way traffic lane and maintenance crane.

d. Access road for process area shall be arranged 1.5 to 4.5 m apart from the closest equipment edge to prevent vehicle collision

3.3

Pipe racks and Sleepers a. In general, as the principal means of support of the pipe ways: •

use pipe rack for Process area

•

use sleeper for Offsite area

b. The width of the pipe ways shall be base from the piping requirements c. For Pipe rack at process unit the width also to consider the tube length of air-cooled heat exchangers.

d. Pipe rack height shall be limited to three levels.

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4

PLANT LAYOUT CONSIDERATIONS Detail plant layout studies and investigations should be carried out to find an adequate layout by considering, but not limited, to the following: •

Access to the plant site

•

Soil conditions

•

Site elevations

•

Routes for products, utilities, effluent water and chemicals including major underground facilities

4.1

•

Prevailing wind direction

•

Facilities adjacent to the plant site

•

Other local requirements

•

Future expansions

•

Lowest lifecycle cost

•

High hazard operation

•

Critical operations

•

Grouped operations

•

Natural hazard and climate

•

Fire and explosion exposures

•

Classification of hazard

•

Drainage and grade sloping

•

Maintenance and emergency accessibility

CONSIDERATIONS FOR PROCESS UNITS Process units should be located at the center of the plant site.

Process units and equipment in the plant should be located in such a way that the product flow conditions are logical in view of the process flow so that the length of piping, especially for large size pipe or pipe using high grade material, should be kept to minimum.

The process units shall be placed to facilitate access from the fire station by avoiding the routes along the tank facility and other facilities having high fire risk. The process units should be surrounded by roads for free movement of fire equipment, operation and maintenance. An adequate alternate access route should be provided for emergency evacuation. Process units present high risks of possible accidents due to the substantial amount of flammable fluids that they handle and their severe operating conditions. It is preferable, therefore, for process units to be located so as to minimize their hazard to surrounding facilities.

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For the big integrated process units, the clearance between the process unit and the other units and facilities should be such that the process unit can be safely maintained even under all other units and facilities around the process unit are in operation.

To facilitate gravity flows in the drainage systems, the process units should be located preferably at the higher location of the plant site.

4.2

CONSIDERATIONS FOR UTILITY FACILITIES Utility facilities are vital for operating plant at all times, i.e during normal operation, startup, shutdown, maintenance, and emergencies.

The utility generation and storage facilities should be located near the process units especially for large consumers, and should be easily accessible and thoroughly protected. Utility facilities, such as potable water system, air system, and nitrogen system, shall be located together so that the area of these facilities can be classified as non-hazardous area.

Utility distribution systems should be as close as possible to each other in the systems to minimize loss within the system and lowering running cost. Utilities should be distributed and routed via pipeway such as pipe rack, sleeper or underground depending upon the service conditions.

The following utility facilities are typical: 1. Electrical system The electric power receiving station should be located close to the receiving point and the large electric power consumers. The electrical distribution network and arrangement of substations should be based on the result of the electrical design. Electric power generation systems should be normally located in the utility area. 2. Potable Water systems The potable (drinking water) water storage and pumping system should normally be located in the utility area. If the potable water is only used in the administration area, the facility can be placed in the administration area. Potable water system should not be connected to any other water and utility system. 3. Air system Air compression, drying, and storage systems should be located in the non-hazardous utility area.

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4.3

CONSIDERATIONS FOR STORAGE FACILITIES Storage facilities shall be basically laid out so as to minimize the transfer distance. The applicable codes and standards shall apply for safe distances of equipment.

The following safe distances, however, must be provided for the storage areas: 1. Crude Oil Storage Tanks •

Minimum distance from tank edge to fence line or boundary line is 60 m.

•

Minimum distance between tanks (edge to edge) is 91 m. Note that this is governed by the bund capacity/size and exceeds the safe distance recommended by NFPA 30.

•

Minimum distance from tank edge to toe of bund is 24 m with at least 15 m to be sloping away from the tank at 1:100 grades.

•

Minimum distance from toe of bund to property line is 3 m.

2. LPG Spheres •

Minimum distance from sphere edge to fence line or boundary limit is 60 m.

•

Minimum distance from sphere edge to uncontrolled road is 30 m.

•

Minimum separation distance between spheres is 12 m to allow for any changes in the diameter of the spheres.

4.4

CONSIDERATIONS FOR LOADING FACILITIES??? The oil from the OTF shall be piped to a jetty berth located about 4.2 km from the OTF. The loading line shall go from the plant site along the jetty to the end of the pier. Two off 10” loading arms shall be provided at the jetty for oil transfer to the tankers. The existing OPF 10” condensate loading pipeline shall be re-used for the mixed LPG loading. The LPG shall be pumped from the storage spheres via this pipeline to a new LPG loading arm that shall be located at the end of the jetty, the position of which is to be approved by PT Maspion.

4.5

CONSIDERATIONS FOR DIKES The crude oil tanks shall be located on a hard stand surrounded by a bund wall. The capacity of the bund shall be 110% of tank capacity. The hard stand shall slope away from the tank to a sump with a drain line from the lowest practical point provided to drain rainwater from the bund. There shall be a normally closed manual valve on this line located outside the bund. The drainage capacity shall be equivalent to the emergency firewater application rate.

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Drainage from areas likely to contain contaminants (drip trays and condensate tank bund) shall be routed to the drains system for further treatment. Operational procedures shall be developed to manage drainage of the tank bund to ensure the bund is drained immediately following rain.

4.6

CONSIDERATIONS FOR FLARE STACK SYSTEM Flare stack with a knockout drums should be normally sited in a low-level area to optimize the slope in the flare header piping. Moreover, flare stacks should be sited upwind or side wind of the process units and tank yard, and sufficiently far from buildings. For spacing, refer to Section 4.0. The sterile zone should be calculated based on the thermal heat radiation at maximum flow conditions. The height of flare stack should be decided based on the requirements for emission control and heat radiation. No equipment and facilities should be basically located within the sterile zone around the flare stack.

4.7

CONSIDERATIONS FOR FIRE AND SAFETY SYSTEM The fire and safety system should be designed and arranged in accordance with applicable codes and regulations. Typical layouts for major fire protection and safety facilities are as follows: 1. Fire water storage and pump Normally, the fire water pump is located in the utility area at the side of fire water tank(s). 2. Fire water distribution network The fire water distribution network piping should be laid out along the roads. Fire water hydrants and monitors should be installed on the fire main line at specified intervals. 3. Other fire protection systems Other fire protection systems should be provided and arranged in accordance with applicable codes and regulations. Those systems are as follows: •

Water spray system.

•

Air foam system.

•

Fire extinguishers and hose boxes.

•

Fire alarm and gas detection system.

4. Safety showers Safety showers with an eye wash station should be placed at strategic locations close to areas that are possible sources of hazardous fluid leaks.

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4.8

CONSIDERATIONS FOR ROADS The roads and access ways should be designed according to traffic conditions, such as the maximum size of vehicles using them, and frequency of use for operation and maintenance and fire fighting activities. Each facility within the given plant site should be divided into several areas by means of the primary roads, secondary roads, maintenance roads and access ways. Sufficient overhead clearance should be provided to cater for such traffic and in accordance with the applicable codes, regulations and specifications.

Emergency Escape Routes Adequate, properly designed escape routes and refuge areas should be provided for use in an emergency, such as fluid/gas leak, explosion, or fire. The roads will be utilized for the escape routes. The administration areas and future areas (if available) will be utilized for refuge areas. The following are typical escape routes:

4.9

•

Route for escaping from equipment structures.

•

Route for escaping from hazardous areas.

•

Route for escaping from dike areas.

•

Route for escaping to upwind direction.

•

Route for escaping to high elevation areas.

CONSIDERATIONS FOR DRAINAGE SYSTEMS Drainage system design shall be as per the “Design Criteria for Civil and Structure” (specification No. UPD-TJ-P2-CI-SP-1001) and “Specification for Roads, Pavement, Sewage, Drainage & Fence” (specification No. UPD-TJ-P2-CI-SP-1009)

4.10 CONSIDERATIONS FOR PLANT BUILDINGS Typical plant buildings are: 1. Substations Substations should be located at strategic points close to the electric consumers considering distribution power cabling routes and length. Substations shall not be located inside hazardous areas.

2. Analyzer shelter There are three types of analyzer shelter (3 sides only no enclosed structures) as follows: •

An analyzer cubicle provided by the analyzer vendor (prefabricated).

•

An analyzer shelter provided by analyzer package vendor (prefabricated).

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Work Sequence Piping Planning & Design Expertise •

An analyzer shelter fabricated at site.

•

The type selection and location of analyzer shelter should be determined by the instrument design. Piping of hydrocarbon gases to safe location is required.

4.11 CONSIDERATIONS FOR NON-PLANT BUILDINGS AND FACILITIES There are many kinds of non-plant buildings and facilities, which will vary according to the type of plant being built. Such buildings and facilities should be located as follows: •

Upstream of the prevailing wind to avoid any gas emissions from the plant.

•

Close to the public road to the plant site to minimize access to plant area and facilities.

•

Far away from the plant units to keep a safe distance from ignition sources and other hazards.

The following are typical non-plant buildings and facilities: •

Car Park in the plant area. Car park area shall be provided. Open spaces around the facilities in non-hazardous area or side of road are normally used for car parking, unless otherwise specified.

4.12 CONSIDERATIONS FOR FUTURE SPACE Future space provisions should be made in accordance with contractual requirements. Future space is typically reserved for the following facilities: •

Future process plants.

•

Future piping space on pipe ways if required.

•

Future electrical and instrument cable ways if required.

4.13 CONSIDERATIONS FOR PIPEWAY LAYOUTS a. Pipeway Routing Pipeways shall be provided to interconnect piping between the process units and the storage tank system, between process units, etc. Pipeway routes should therefore be planned concurrently with the area allocation planning for the plant facilities and with the road route planning.

b. Pipe Racks Pipeways in the process units and a part of utility facility areas should be on pipe racks to ease equipment and piping layout and to facilitate access from both sides of the pipeway and will be applied to the following piping:

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Process interconnecting piping between process units (interconnecting pipe rack).

•

Process and utility piping within process units and utility units (unit pipe rack).

•

Utility piping from utility facilities such as the generators, air compressors, etc. to process units.

•

Free drain for specific service such as flare and blow down headers.

The pipe racks should be arranged so that they cross all process unit areas in as straight a line as possible, at the centre or at the end of process areas, so that access to each unit can be made without passing through below the pipe rack.

The elevation of pipe racks should be determined considering the following requirements: •

Overhead clearance for maintenance access.

•

Required space between two tiers of piping.

•

Height difference between interconnecting and unit pipe racks.

c. Pipe Sleepers Pipeways in areas other than the process unit and a part of utility facility areas should be on pipe sleepers for economical design. A pipe culvert or pipe bridge should be used at road crossing.

d. Elevated Pipe Supports Pipe stanchions or pipe supports are normally provided for the following piping: Flare piping from the process units to the flare system. Piping system at the tankage area.

4.14 CONSIDERATIONS FOR EQUIPMENT LAYOUTS The main considerations when deciding the layout of typical equipment are described below. Operational patrol route should also be considered into equipment layout and access plan.

a. Fired Heaters 1. Location Fired heaters should be located upwind of other process equipment, such as vessels, pumps and compressors handling light hydrocarbons so that the possibility of vapor being carried toward open fires can be minimized. Normally, fired heaters should be located at the corner or end of a process unit to provide an emergency access for fire fighting vehicles and evacuation from the area.

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2. Access and Maintenance Space should be reserved around heaters for removal and installation of heater tubing for repair and replacement. The space required will varies depending upon the type of heater, length of tubing and maintenance procedure.

b. Towers 1. Location Towers should be located beside a pipe rack, normally as a set with bottom pumps. The related overhead condenser and overhead drum should be placed beside the tower. 2. Access and Maintenance Manholes of towers should be oriented toward the maintenance access side. A dropout area should be provided for each tower for installation and removal of trays and internal packing.

c. Vessels 1. Location Vessels should be located to satisfy all process requirements. Normally, vessels should be located alongside pipe racks in the order of the processing sequence. Horizontal vessels should be normally located so that the longitudinal directions of the vessels and the pipe rack are perpendicular to each other. Vertical vessels should be located close to a pipe rack whenever possible to shorten the length of piping. The depth of underground drip vessels should be such that drainage can be collected by gravity without a pocket. These vessels should be installed in concrete pits as secondary containment to avoid leaks to soil and ground water.

d. Shell And Tube Heat Exchangers 1. Location Generally, heat exchangers should be located perpendicular to the related pipe rack with the channel side facing toward the maintenance access side to allow easy removal of the tube bundles. Heat exchangers can be stacked on other heat exchangers so that the plant area is effectively used, but stacking should be limited to two levels. The elevations of the heat exchangers should normally be established during piping design, except when there are specific process requirements, such as for liquid level of reboilers, gravity flow, seal height in vacuum service, NPSH etc.

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2. Access and Maintenance Adequate clearance shall be provided in the direction that the tube bundle will be withdrawn. If a heat exchanger is installed under a structure and its tube bundle can not be pulled out by a crane, a hoisting monorail beam should be installed to withdraw the tube bundle. Piping or cables should not be laid out over the channel or shell cover for easy lifting of the tube bundle for maintenance.

e. Pumps 1. Location Generally, pumps should be grouped and located in a line near relevant vessels and pipe racks. Normally suction of pumps should face toward the inlet nozzle on suction vessels to simplify piping arrangement. The pump drivers should face toward the pipe rack to simplify the installation of power cabling. No pumps shall be located under a pipe rack. Pump foundations should be high enough to drain out, but not so high that pump NPSH is significantly changed. When two or more similar type pumps are located close to each other, one of the following line-up methods should be applied: •

Line-up by discharge nozzle center line.

•

Line-up by motor side foundation edge.

•

Line-up by pump side foundation edge.

2. Access for Operation and Maintenance For easy operation and maintenance of pumps, access should be provided at the front and back of each pump. Also sufficient space should be provided around pumps for cleaning of suction strainer, alignment, lubrication etc. If it is necessary to lift heavy components and can not be directly handled by forklift, mobile crane or portable hoist, an adequate size of monorail shall be provided.

f. Compressors 1. Location Normally, compressors should be located by position in the processing flow sequence, together with other related equipment, such as the suction drum, inter-cooler, after-cooler, etc. Compressors should basically be installed on a concrete foundation at grade to support the heavy deadweight and large dynamic force they generate. However, if an advantage is

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foreseen in the piping routing arrangement, the compressor should be on a tabletop concrete structure. The necessity of a shelter is for compressors depends on the local weather conditions and operation and maintenance requirements. A compressor shelter when provided should be an open-air type to avoid accumulation of flammable gases in the shelter.

2. Access and Maintenance For easy access and maintenance, the compressor should preferably be located close to maintenance access way. An adequate lay-down space should be provided for maintenance or overhauling, and clearance necessary to remove compressor components shall be provided around the compressor according to the requirements of the compressor vendor.

3. Auxiliary Equipment The local control panel, if any, should be located close to the compressor. The lube oil and seal oil console unit should be located as close as possible to the compressor, in accordance with the compressor vendor’s recommendations.

4. Special Considerations For reciprocating compressors, the results of the pulsation analysis should be reflected in the layout around the compressors, piping and other related equipment.

g. Air Cooled Heat Exchangers (AFC) 1. Location Air-cooled heat exchangers (normally called as “AFC”: Air Fin Cooler) may be located on the top of pipe racks or structures wherever possible to save plot space. Pumps and other similar equipment handling flammable fluid shall not be located beneath the AFC so as to prevent fires spreading due to leakage from such equipment. The elevation of the AFC should suit process requirements, such as for a gravity flow to the overhead condensate reservoirs. To minimize the piping length between the AFC and the connected equipment the number(s) of pass should be considered in the plant arrangement. Note: Position of inlet and outlet nozzles for even number pass shall be same side.

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2. Access and Maintenance Operation and maintenance platforms/walkways are to be provided for AFC as follows: •

A platforms/walkways at both ends of the tube bundle headers.

•

A platforms/walkways beneath the fans and motors.

•

A platforms/walkways on top of induced draft fan AFC.

Grating should be used for the platforms/walkways beneath fans and motors. The elevation of the AFC should be determined to avoid hot air re-circulation. The high level platforms of tower etc. planned to locate near AFCs should be placed to keep adequate distance to avoid hot air exhaust flow. All AFC’s shall be equipped with removable bug screen which fully enclose the cooler structure (sides and bottom). Washing apparatus for air cooler shall be provided such as utility station, hose, etc.

5

PLANT AND EQUIPMENT SPACING

5.1 OBJECTIVE The objective of the plant spacing requirement is to ensure that the most economic use is made of the available plot area, compatible with the safety of equipment & personnel, environmental aspects and the vulnerability of the Plant. This will minimize interruptions to business in case of a fire or explosion in the plant. To achieve this objective, the following precautions must be considered in addition to the regular requirements regarding accessibility for normal operation and maintenance: 1. Protecting adjacent facilities in the event of a fire or explosion 2. Limiting the escalation of fire or explosion and preventing larger losses 3. Segregating high risk facilities and probable ignition sources 4. Protecting critical emergency facilities 5. Accessibility for emergency operation 6. Providing accessibility for evacuation of personnel 7. Providing accessibility for fire fighting 8. Ensuring the security of installations from outside hazards 9. Minimizing danger and inconvenience to personnel and property beyond the boundary fence.

In addition to the above, required spaces for the plant and the plant layout shall be designed to meet the requirement for operability, accessibility and maintainability, constructability, and for fire fighting shall be provided. WORK SEQUENCE

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5.2

BASIC SPACING The basic spacing for equipment and facilities are summarized in table as follow:

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5.3

OVERALL PLANT SPACING REQUIREMENTS

The information in that chart shall be supplemented by the following explanatory notes:

A1.

Property Boundary Lines

The basic spacing protects personnel and property outside the property boundary line in the event of a fire or explosion. It also protects the facilities inside the property line from external hazards. The basic spacing is pertinent to public and private residential areas, and may be reduced if an industry site neighbors the plant site.

B1.

Main Plant Entrance

The basic spacing protects personnel when they pass through the main entrance in the event of a fire or explosion in the process area, tankage area, loading facilities and other facilities that are ignition sources.

C1.

Non plant Buildings

The basic spacing protects personnel occupying non plant buildings from the effect of a fire or explosion in the process area, tankage area, loading facilities and other facilities that are ignition sources.

E1.

Main Electrical Substation

The basic spacing protects critical electrical equipment in the main substation in the event of a fire or explosion mainly in the process area. For the small installations where the main substation and unit substation are integrated, the spacing for unit substation described in Appendix-3 (Onsite Spacing Chart)

F1.

Main Fire Pumps

The basic spacing guards against loss of the main fire pumps from fire exposure.

G1.

Process Unit: High-Hazard Service

The basic spacing minimizes damage to other plant areas or equipment in the event of a fire or explosion in the high-hazard process area and vice versa. The spacing shall be measured from the edge of each item of equipment in the process area. If high-hazard and other process plants are integrated to simplify operation and economize on the installation cost, such combined process area shall be treated as one high-hazard process unit.

H1.

Process Unit: Intermediate-Hazard Service

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The basic spacing minimizes damage to other plant areas or equipment in the event of a fire or explosion in the intermediate-hazard process area and vice versa. If intermediate-hazard and moderate-hazard process plants are integrated to simplify operation, such combined process area shall be treated as one intermediate-hazard process unit.

I1.

Process Unit: Moderate-Hazard Service

The basic spacing minimizes damage to other plant areas or equipment in the event of a fire or explosion in the moderate-hazard process area and vice versa.

J1.

Power Generation

The basic spacing protects critical equipment from a fire or explosion in process area, also protects personnel in the non-industrial building area from a fire or explosion in these f acilities.

K1.

Primary Roads in Premises

The basic spacing protects personnel and vehicles traveling the primary roads if a fire or explosion occurs in facilities handling flammable materials and toxic materials.

Also, the basic spacing protects the plant from sources of ignition on those the roads, such as vehicles. For a small-scale plant, the primary roads can be read as plant roads described in Appendix-3 (Onsite Spacing Chart).

L1.

Offsite Main Pipeway

The basic spacing minimizes the hazards to offsite piping in the event of a fire in a major plant area.

M1.

Atmospheric Storage Tanks

The basic spacing protects personnel and facilities in the storage tank areas in the event of a fire or explosion in the process area and vice versa. The detail spacing for tanks such as between tanks, between the tanks and dikes, etc. shall be in accordance with the applicable local regulations. Normally, local regulations are based on NFPA30 or IP3: Refinery Safety Code (IP: Institute of Petroleum) with required supplements. The flash point of the stored fluids is used to classify the storage tanks and apply spacing requirements accordingly.

N1.

Offsite Major Pump Areas

The basic spacing protects these offsite major pumps in the event of fire or explosion in the process areas and storage tanks.

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O1.

Elevated Flares

The basic spacing protects personnel and facilities inside and outside the plant boundary line from the thermal heat radiation in the event of a large discharge of vapor to the flares. This spacing also protects the process unit from fire if vapor is released to the atmosphere in the process units.

P1.

Wastewater Treating Facilities

The basic spacing protects the high risk items of the wastewater treating facilities such as oil separator etc. from the process areas and other sources of ignition. The basic spacing also considers the unpleasant effects on personnel from mal-odors.

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5.4

ONSITE SPACING REQUIREMENTS

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The information in that chart is supplemented by the following explanatory notes. (Note that equipment items not specifically describe mentioned as “Non-flammable” are intended for flammable service.)

A2.

Fired Heaters

The basic spacing separates equipment handling flammable vapors from a permanent source of ignition, such as a fired heater, and affords protection in the event of a major heater fire. The spacing between fired heaters and related equipment with operating temperature below AIT, can be reduced to the minimum distance necessary for maintenance and fire fighting.

Fuel gas KO drums shall be located not less than 7.5 meters from fired heaters. The air intake for the forced draft fan for the fired heaters should be located on the outside of hazardous area. The requirements concerning the fired heaters and auxiliary equipment, such as a forced draft fan, induced draft fan and stack, are the space for maintenance and operation.

B2.

Process Pumps Operating above AIT or 316°C

Pumps operating above AIT or above 316°C are a fire risk. So, the basic spacing provides access for fire fighting and is designed to minimize damage to other equipment. Pumps operating above AIT can be grouped and can be spaced 1.5 m apart as required for operation and maintenance.

C2.

Process Pumps Handling C4 and Lighter

The basic spacing provides access for fire fighting and is designed to minimize damage to other equipment. Pumps in the same category (C2) may be spaced as dictated by operation and maintenance requirements. Gas compressors rated below 500kw are included in this category for spacing purposes.

D2.

Process Pumps Operating below AIT

The basic spacing provides access for fire fighting and is designed to minimize damage to other equipment. Pumps in the same category (D2) may be spaced as dictated by operation and maintenance requirements.

E2.

Compressors and Expanders for Flammable Gas Service

The basic spacing is not applied between compressors since normally compressors are installed together with their auxiliaries in a designated area. The spacing provided shall therefore be that required to facilitate operation and maintenance.

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F2.

Diesel Engine for Pumps and Compressors

The basic spacing for this category of pump and compressor protects it against other hazardous equipment, since the drivers are regarded as a source of ignition. However, the spacing between other equipment operating within AIT can be reduced. The basic spacing between gas compressors and gas turbine/engines and diesel engine drivers is not applicable. The air intake for these drivers should be from outside the hazardous area.

G2.

Heat Exchangers Operating above AIT or 316°C

The basic spacing is designed to minimize damage to other equipment in the event of fire. All heat exchangers operating above AIT can be grouped together, in which case the basic spacing is not necessarily applied and can be reduced to that necessary for operation and maintenance.

H2.

Heat Exchangers below AIT or 316°C

The basic spacing provides access for operation and maintenance. There are no limitations on spacing exchangers from pipe racks.

I2.

Air-Cooled Exchanger for Hydrocarbon Service

The basic spacing is designed to minimize exposure of the mechanical components of air-cooled exchangers to fire since they are more vulnerable to fire damage. Moreover, the basic spacing is designed to minimize the spread of fire beneath the air-cooled exchanger by a forced draft effect to other equipment in event of a fire. Leakage of hydrocarbons from air-cooled exchangers leads to fires at high temperature equipment or piping beneath the air-cooled exchangers. The basic spacing may be ignored if air-cooled exchangers are installed beyond 15 meters from the top of flammable equipment. To calculate the spacing between an air-cooled exchanger on a structure and another items of equipment located at grade, the horizontal distance between the equipment as shown on the plot plan view shall be used.

J2.

Air-cooled Exchangers for Non-Hydrocarbon Service

The basic spacing is the same as I2. Leakage from air-cooled exchangers in this service does not affect equipment beneath the aircooled exchangers.

K2.

Towers & Drums

The basic spacing provides access for fire fighting, operation and maintenance and is designed to minimize damage to the other equipment. Towers and drums handling nonflammables are

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included in section N2. The spacing between a tower and a vertical reboiler is for maintenance purpose only.

L2.

Onsite Pressure Storage Tanks

The basic spacing minimizes exposure of the unit equipment to a potential source of severe fire, and blast damage in the event of an explosion. The detailed spacing and provision of dikes etc. shall be in accordance with applicable local regulations.

M2.

Onsite Atmospheric Storage Tanks for Flammable Service

The basic spacing minimizes exposure of unit equipment to a potential source of tank fire, and outbreaks of fire and explosion in process equipment, and vice versa. Onsite atmospheric storage tanks are normally the cone roof type and the floating roof type for hydrocarbons.

N2.

Equipment Handling Nonflammable Materials

There is no spacing requirement for this item, except for access for operation and maintenance. The basic spacing for toxic chemical handling equipment is for operation, maintenance and emergency escapes.

O2.

Shutdown Valves (SDV)

The basic spacing is the distance between the SDV and the equipment to be protected. SDV can be located adjacent to other equipment. Note that the battery limit valves installed at the unit limit for use during plant shutdowns are not included in this category.

P2.

Unit Substations

The basic spacing is fixed by the hazardous area classification considerations. The basic spacing provides protection to the electrical equipment in the event of fire.

R2.

Onsite Main Equipment Structures

There are no basic spacing requirements. Space is provided merely for operation and maintenance. The onsite main equipment structures are protected by mean of fireproofing when necessary.

S2.

Onsite Main Pipe Rack

There are no basic spacing requirements. Space is provided merely for operation and maintenance. The onsite pipe racks themselves are protected by means of fireproofing when

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necessary. The sub pipe racks in front of the fired heaters are not included in the onsite main pipe racks because of their proximity to the fired heaters.

T2.

Plant Roads

The roads around and inside the process areas shall be considered in this category for spacing purposes. The plant roads are normally restricted to vehicle traffic by barriers and sign at the entrance. The basic spacing protects equipment and facilities from vehicle collisions.

U2.

Analyzer Shelter

The basic spacing protects instruments in the analyzer shelter in the event of fire. Analyzer shelter means those shelters containing analyzer equipment which require analyzing operation by operator.

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5.5

INCREASING THE SPACE REQUIREMENTS The spacing requirements in this specification are for common application, and the spacing when the following conditions arise: •

Special process hazards that justify increased spacing.

•

Special plant maintenance or installation considerations which may necessitate increased spacing.

•

Future development plans, both inside and outside the boundary fence.

•

Proximity of adjacent property and consequential environmental and public relations effects.

•

5.6

Political security factor.

RELAXATION OF SPACE REQUIREMENTS The relaxation of spacing may be permitted to meet the specific conditions such as process requirements; area limitation etc. with owner’s approval if the f ollowing provisions are made: •

To add additional fire fighting provisions such as water spray, water curtain, steam curtain, fire fighting equipment, emergency shutdown device, etc.

•

To provide isolation wall to separate equipment from the hazardous sources.

•

To provide additional escape routes.

•

To provide additional fireproofing.

•

To add drainage system

•

To add remote/safe shutdown device

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6

DETAIL PLANT LAYOUT

6.1

PLANT ELEVATION

1. EL. ± 0 = MSL + 2000 mm

2. EL. (-) 200 mm max is the lowest point (top of the open ditch etc.) of the process and utility area.

6.2 PAVING 1. Part of process, utility and buildings area will be paved with concrete as required. 2. Maximum catchments area for surface drainage of concrete Kerbed area should be 300 m2 or smaller. 3. The surface slope in the Kerbed area shall be not less than 1 %. For other grading area should be 1/200 to 1/500 minimum slopes.

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6.3

CLASSIFICATION OF ROADS AND ACCESSES

Roads and accesses are classified as follows: 1. Primary roads •

Accesses between the plant site main gate and main plant area.

•

Accesses between the truck gate and truck loading station.

2. Secondary roads •

Accesses around units and facilities.

•

Accesses around the pump station for storage tanks.

•

Accesses around waste water treating facilities, flare.

3. Maintenance roads (access way) •

Accesses to flare stacks, other auxiliary facilities in offsite area.

•

Access between the entrance gate for large, heavy and lengthy equipment to strategic areas within the plant site, such as the process area and utility area.

•

Access for future expansion area(s).

•

Access for AFC and compressor in process and utility area.

•

Access to electrical transformers.

•

Access to switchgear building equipment door.

•

Access to instrument and telecom room equipment doors.

4. Fire truck access A minimum 4 metre wide access shall be provided for fire truck access. If the 4 metre wide access is longer than 100 metre, a minimum 6 metre wide section 10 metre long shall be provided for vehicles to pass each other.

5. Personal access •

The dimension and headroom clearance for personal access shall be in accordance with the following table: Personal Access Access width

0.75 metre

Headroom clearance *

2.1 metre

* If there is a platform on the top of a vessel and the vessel is located under a structure and the platform is mainly used for maintenance, the headroom shall be reduced to the lower side of the upper level floor.

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The main personal accesses are: o

Access from central control room to the plant.

o

Access to and around major machinery, such as compressor, large pumps, etc.

o

Access in front of a group of pumps.

o

Access for a group of control valves.

o

Access between pumps.

o

Access to PSV.

o

Access to isolation valves for maintenance.

o

Access for operating valves that are merely manipulated, including access for operating drain valves.

6.4

ROAD

1. Width of road shall be as follows: •

Primary roads

: 6 m + 1.0 m shoulders (max. slope 8%)

•

Secondary roads

: 5.5 m + 1.0 m shoulders (max. slope 8%)

•

Maintenance roads

: 4 m without shoulders (max. slope 8%)

(access way) (based on 50 ton crane)

2. Headroom clearance of road shall be as follows: •

Primary roads

: 6.1 m

•

Secondary roads

: 4.875 m

•

Maintenance roads

: 4.2 m (as minimum)

(access way)

3. Radius of road corner to be shown as follows: •

6 m road

: R = 12 m

•

5.5 m road

:R=8m

•

4 m road

:R=6m

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4. Lighting electrical cables and fire fighting pipe lines shall be installed underground of the shoulder area.

TYPICAL SECTION FOR U/G FACILITIES ALONG ROAD

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6.5

UNDERGROUND FACILITY

The following lines and systems shall be underground: 1. Electrical Cable. General area lighting & perimeter lighting as specify on UPD-TJ-P2-EL-SP-1011 "Specification for Electrical Installation". 2. Drain Open Oily Water (DO) and Drain Closed (DC) lines for process and utility area. 3. Fire Water ring main. 4. Amine drain header. 5. Drain Sanitary (DS) lines.

6.6

TOP ELEVATION OF FOUNDATION

Elevation shall be adjusted if the relevant elevation above is inadequate for process and mechanical reasons such as draining, flange bolting, spectacle blind handling, etc.

Item

Elevation

Column

: HPP +300 mm

Drum Vertical

: HPP +300 mm

Drum Horizontal

: min. HPP +300 mm

S/T Heat Exchanger

: min. HPP +300 mm

Pump

: min. HPP+300

Compressor

: by vendor

Tank

: min. HPP +500 mm

Pipe Stanchion

: HPP +300mm

Operating Platform

: HPP+150mm

Package Equipment

: min. HPP+150mm

Pipe Sleeper

: min. HPP +300 mm

Pipe Support (on paved area)

: min. 25 mm

Pipe Support (not paved area)

: HPP+150mm

Steel Pipe rack & Structure

: HPP +300mm

Ladder Stairway

: max. 200 mm

Notes: (1) The height of the top surface of foundations for equipment and structures above the high point of the paving shall be as follows.

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6.7

MINIMUM DISTANCE BETWEEN EQUIPMENT AND ROAD

A minimum distance of 5 m shall be maintained between the edge of primary and secondary roads (included shoulder) and hydrocarbon containing equipments.

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6.8

STRUCTURE LAYOUTS

6.8.1

CONSTRUCTION OF STRUCTURES

1. Type of floor materials a. Grating floor: minimum use for the following areas & general purpose •

Maintenance floor for Air Fin Coolers (AFC's).

•

Compressor maintenance floor.

•

Areas requiring ventilation for safety considerations.

•

Grating shall not be used in areas of heavier than air hydrocarbon where pooling can occur.

b. Concrete floor: Specific use for the following areas: •

Toxic fluid spill is expected and required to be collected at the floor.

•

Fire isolation from lower level is required.

•

Frequent maintenance by mobile equipment is required.

•

Clean and silent conditions are required for operation.

2. Base level of floor elevation The base level of floor elevation shall be as follows: a. Grating floor: Top of grating. Note: The minimum headroom for personnel (2.1 m) can be calculated from the top of floor elevation even though this reduces actual headroom a little.

3. Floor drains Drainage to the floors in the plant areas and buildings shall be collected in accordance with following concept: a. Oily and chemicals are frequently drained. •

Need ability to collect any draining and pipe to ground level for emptying. (Refer to UPDTJ-P2-CI-SP-1001 "Design Criteria for Civil and Structure").

b. Limited amount of oily and chemicals not harmful to personnel. •

Provide a portable can or use of drain hose.

c. Rain water and small steam trap drain such as for line tracing. •

Grating floor: no provision is required.

•

Checkered plate floor: small opening holes on floor plate.

•

Concrete floor: curb and slope to down spout or slope to edge depending upon the service conditions.

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4. Stairs and ladders provisions Elevated floors from the ground shall have stairs and, or ladders based on the following application criteria: a. Stairs Stairs shall be provided for those floor(s) requiring frequent access for operation and maintenance using hand tools, etc., such as for the following: •

Floors for compressors or turbines.

•

Floors for vacuum filters.

•

Floors for filling/removing of packing materials during operation.

•

Floor for AFC.

•

Need to carry chemicals, additives, catalyst & supplies as part of routine duties.

b. Ladders Ladders shall be provided for the floor(s) used for operation and routine maintenance check and patrol that normally does not involve using hand tools.

5. Maximum height of ladder and stairway

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For Stairway

•

For Ladder

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•

6.8.2

Ladder will be designed SIDE STEP.

PIPE RACKS

1. Headroom clearance The headroom clearance for a pipe rack (from the grade to the lowest part of pipe rack including piping) shall be as follows:

2.

•

Fire truck access

:

4.5 m

•

Maintenance equipment access

:

4 m (as minimum)

•

Personal access

:

2.1 m

Future piping space Sufficient space shall be provided in the pipe rack design for piping, instrument and

electrical cables, if there are requirements to provide future facilities spaces.

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3.

Typical Layout for process and utility area main piperack

Note: a. Removable bug screen are provided. b. Handrail around work area is provided. c. Power outlet for hand tools is provided. d. No electrical equipment installed under flare header. e. No equipment installed under piperack.

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4.

Typical Layout for process and utility area sub piperack

5.

Configuration of AFC on the piperack If the machinery mount is installed under the AFC, AFC structures shall be provided with

maintenance platforms under the machinery mount such as the motor, gears, fan, etc. The maintenance platform shall have a walkway at the centre of the AFC so that mechanical components can be removed. If AFCs are installed on the ground and machinery mount is low enough for maintenance from the ground, a permanent maintenance platform is not required. Obstruction to Air Fin Cooler's outlet shall not be allowed. Space shall be provided for tube bundle removal/replacement.

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6.8.3

EQUIPMENT STRUCTURES

1.

Design of equipment structures

Equipment structures need up and down access for operation and maintenance. Therefore, the equipment structures shall be designed to ease operation and maintenance wherever required considering the following: •

Minimize number of structures by combining other structures in one structure.

•

Lower floor elevation.

•

Minimize floor surface area.

•

Joining two or more close structures to provide access from one to the other.

2.

Layout of equipment structures

Equipment structures shall be laid out as economically as possible without compromising operation, safety and maintenance requirements. The following are typical structure layouts: •

Independent structures.

•

Common structures with neighbouring pipe racks.

•

Pipe racks used for equipment structures.

3.

Configuration of structure

•

One stairway shall be installed for one structure.

•

Escape ladder shall be considered from the safety protection point of view. Such is case of gas leaks from valve manifold(s), pump located underneath the structure and any other possibility of fire cases.

An actual requirement of escape ladder for individual structure will be confirmed during model review by company.

4.

Hoisting beam S/T heat exchangers in structure shall be installed as follow:

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6.8.4

SHELTERS

1.

Shelters for weather protection

Basically, almost all equipment and machinery for industrial service are designed for weatherproof construction. Therefore those equipment and machinery should be placed outdoor unless otherwise specified. If there are equipment and machinery specifically designed for indoor use shall be placed in the shelter.

2.

Shelter for acoustic abatement

In principle, the machinery manufacturer's acoustic abatement devices shall be applied. However, if the allowable noise level cannot be maintained by the acoustic abatement devices, the machine shall be placed in a shelter having sidewalls. In this case, the noise level shall be measured from the outside of the shelter wall.

3. •

Compressor Shelter Compressor and driver may be installed on the concrete table top foundation. Also, platform may be installed for reason of operating and maintenance.

•

Compressor and driver shall be located in the shelter structure with overhead or hoist, capable of lifting heaviest component.

•

S/O and L/O consoles may be located out of shelter structure, however lube oil console shall be equipped with a roof.

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The overhead traveling crane shall be capable of moving to a point over top of the drop area to lower parts down to grade or waiting truck.

4.

Shelters shall be designed such that rain water ingress to WC drain system is minimized.

6.8.5

OPERATION AND MAINTENANCE FLOOR

1.

Centrifugal compressor maintenance floor

Centrifugal compressors installed on high elevation shall be provided with a maintenance floor. 2

The maximum live load is 2.87 KN/m as per civil & structure design criteria on the maintenance floor with condition that all parts of compressor not to be directly supported by the compressor deck.

2.

Unit battery limit valve platform

A valve platform shall be provided for the unit (battery) limit valve manifolds on the pipe rack. The platform shall have a stairs accessible from grade. If unit battery limit valves can be placed at the ground, the platform is not required.

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3.

Unit battery limit valve platform

A valve platform shall be provided for the unit (battery) limit valve manifolds on the pipe rack. The platform shall have a stairs accessible from grade. If unit battery limit valves can be placed at the ground, the platform is not required.

6.8.6

WALKWAYS

1.

Connecting walkways

Connecting walkways shall be provided at the following locations if the floor at both ends is elevated by less than 2 m: •

Between equipment structure floor and 1'' level of a tower platform that has a level gage, etc. requiring frequent monitoring during operations.

•

Between the 1" levels of tower platforms for the same reason mentioned above.

•

Between an equipment structure floor and AFC maintenance platform to permit common usage of the equipment structure stairs for access to the AFC.

•

Between an AFC maintenance platform and valve platform if both platforms are on the same pipe rack and they are closer than 5 m apart.

•

Between an equipment structure and valve platform at the process unit battery limit if they are closer than 3 m apart.

2.

Crossing walkways

Crossing walkways shall be a combination of stair, ladder, platform, concrete cover etc. depending upon the needs. Crossing walkways shall be provided at the following locations if there is no alternative access: •

At no more than 100 m intervals across a road in the offsite area if there is a long sleeper pipeway running parallel to the road.

•

At no more than 100 m intervals across an open ditch if the open ditch is wider than 750 mm.

•

Across an intermediate dike.

•

Across sleeper pipeway.

•

At no more than 40 m intervals across a dike if there are intermediate dikes crossing and pipeway crossing inside the dike.

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7

MAINTENANCE CONSIDERATION The maintenance and operation activities to be considered into the plant layout design are as follows: •

Removing and reassembling equipment components.

•

Filling and withdrawing internals, packing and catalyst.

•

Filling lubricants and adjusting machinery.

The preventive and predictive maintenance work, including the provisions for machine monitoring, corrosion monitoring etc. are not covered.

7.1

CLASSIFICATION OF MAINTENANCE WORK There are several classifications of maintenance work as mentioned below. Prior to finalizing the plant layout, the maintenance requirements for all equipment and machinery shall be checked and reflected into the plant layout.

The maintenance work for a typical project is classified as follows according to timing and activity:

1.

2.

3.

Classification by Timing and Activities. •

Daily maintenance work.

•

Periodic maintenance work (weekly, monthly, etc.).

•

Shutdown maintenance work (yearly/scheduled, unexpected, etc.).

•

Operational work.

Classification by Equipment/Devices to be used. •

Maintenance done manually without any lifting device.

•

Maintenance using lifting device.

•

Maintenance using mobile maintenance equipment.

•

Maintenance using permanent maintenance equipment.

Classification by Work Place to Carry out Maintenance Activities. •

Maintenance at place installed.

•

Maintenance at drop out area and/or at maintenance space around equipment.

•

Maintenance at workshop.

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7.2

Maintenance at manufacturer’s shop.

DESIGN OF MAINTENANCE PROVISIONS The plant shall be designed to enable easy, economic and safe maintenance operations. The maintenance equipment and tools to be used shall be easily operable and safe. Maintenance provisions shall be designed in accordance with the concept outlined below.

1.

Use of Mobile Lifting Equipment The plant shall be designed to maximize the use of mobile lifting equipment. To utilize mobile lifting equipment, an adequate access shall be provided at first in the plant layout so that the mobile lifting equipment can safely and easily approach the subject equipment, and be fully operated for the maintenance work.

2.

Use of Permanent Lifting Equipment Overhead cranes are normally installed in workshops/warehouses for heavy duty service, and in compressor shelters and similar buildings where mobile lifting equipment can not access.

Permanent lifting equipment, such as jib cranes and gantry cranes shall be provided only when required for particular service where maintenance operation by mobile lifting equipment is unsuitable.

3.

Provisions of Lifting Devices •

Lifting devices directly attached to equipment and machinery. Permanent lifting devices shall be directly attached to the equipment itself for the components weighing more than 22 kg to facilitate maintenance work. Typical examples are as follows: o

Davits and/or hinges Filters, towers, vessels etc. to handle manholes/shell cover

o

Top davit Towers, vessels and reactors etc. to lift internals/packing

o

Lifting lugs

o

Covers of shell and tube type heat exchangers etc.

o

Bolt holes

o

Tube sheets of exchangers etc.

o

Eyebolts or eye-plates

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Work Sequence Piping Planning & Design Expertise o

Motors, pumps, etc.

o

Requirements for such permanent lifting devices may be specified in the specification/data sheets for applicable equipment.

•

Lifting devices installed over equipment. Lifting devices such as monorail beams, lifting lugs, jib, etc. will be provided for equipment.

A monorail beam shall be provided for shell/tube heat exchangers, if a mobile crane or a tube bundle puller cannot be used due to space limitations (width, height and depth).

The trolleys, hoists and chain blocks attached to monorails beams are normally stored in the warehouse. However, a permanent hoisting device shall be installed where frequent or periodic maintenance operations are required such as for chemical filling and batch operation.

•

Lifting devices installed for erection purposes. Lifting devices, such as lifting lugs for vertical vessels and towers, shall be provided in accordance with the rigging subcontractor’s recommendations. After erection, the lifting lugs shall be removed if they obstruct the permanent facilities or maintenance work.

For safety reasons no equipment shall be lifted over top of operating equipment.

Any equipment that is located near to the pipe rack that can not be easily accessed shall have lifting davits and beams to facilitate transfer to central corridor of pipe rack for transport.

All shell and tube exchangers located under platforms, shelters, beams or other overhead obstructions shall have a monorail beam system to facilitate the removal of the exchanger bundle.

4.

Provisions for Specific Maintenance The following maintenance work involves very specific activities. Since it is almost impossible to cover every single situation by this specification, the specific

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requirements for maintenance equipment and tools shall be studied and provided when such maintenance work is required during the plant operation.

•

Replacing the entire equipment. This involves replacing the entire piece of equipment, such as a tower, or vessel.

•

Replacing component of equipment. This involves replacing the top or bottom section of a tower and related equipment and machinery to new one when corrosion allowance is consumed. Also replacing bundles of air-cooled exchangers is included in this category.

7.3

DETAILED MAINTENANCE CONSIDERATIONS The specific maintenance considerations for plant maintenance are as follows:

1.

Drop Areas A sufficient space shall be provided for each drop area to simplify maintenance work. The drop area shall be flat and have sufficient bearing strength to receive equipment components to reload them. The drop areas should face the road wherever possible to minimize transportation access to a road.

•

For towers, an adequate drop area shall be provided for tray and internals in front of the tower facing a road.

•

For rotating machinery installed at an elevated location, such as compressors and turbines an adequate drop area shall be provided to receive the components directly on the ground or onto a waiting truck, etc. If the maintenance will be done on equipment components in the drop area, an adequate space shall be reserved around the drop area for the maintenance.

2.

Maintenance Access •

Access from road An adequate maintenance access shall be provided from a nearby road to the equipment requiring maintenance. The maintenance access shall be wide enough and sufficient overhead clearance to transport the equipment components, and everything else associated with the maintenance work. If mobile equipment is

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used, the maintenance access shall be graded flat and have sufficient bearing strength to support the mobile equipment when fully loaded.

•

Access ramps If the mobile equipment must cross a curb, the f ollowing ollowing provision shall be made.

•

o

for frequent maintenance

o

for infrequent maintenance

: :

a permanent access ramp

a temporary access ramp

Stairs and Ladders Permanent stairs shall be provided for frequent maintenance by maintenance personnel that must carry parts, portable maintenance equipment, hand tools, etc. Permanent ladders shall be provided for routine checks and inspections by maintenance personnel and operators that are normally not required to carry portable maintenance equipment, etc.

3.

Maintenance Space Maintenance space around equipment shall be wide enough and have adequate overhead clearance for the maintenance work as follows. •

For shell shell and and tube tube type heat e exchangers xchangers with removable tube b bundles undles o

Open space in front of the heat exchangers for pulling out the tube bundle. If there is a handrail in front of the heat exchanger, the handrail shall be of removal type at that point where the tube bundle will be pulled out of the heat exchanger.

o

Open space to place movable parts such as channel cover, shell cover, floating head cover around the heat exchangers.

•

For mixers and agitators o

•

For filters o

•

Open space for replacing the shaft and impellers.

Open space for removing and installing filter elements.

For fired heaters o

Open space for removing removing and installing heater tubes, soot blowers etc. Roads around fired heaters can be used for this space.

4.

Platform for Packed Vessels

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Platforms for packed vessels such as reactors, absorbers etc. shall be designed to meet the work procedures for filling and emptying of catalysts and adsorbents etc. The platforms shall be wide enough and strong enough for such s uch work.

5.

Maintenance Work Within Hazardous Area Some maintenance work may be done within a hazardous area during normal plant operations. For such work, the following specifications shall in principle apply to the maintenance equipment and tools used:

6.

•

Electrical driven equipment :

Explosion-proof type

•

Hammers, spanners etc.

:

Non-spark type

•

Mobile equipment

:

Exhaust to be equipped with a flame arrestor

Identification of Permanent Permanent Lifting Equipment and Lifting Devices All permanent lifting equipment and lifting devices, such as cranes, monorail beams and hoists shall be clearly and permanently marked the working capacity.

7.

Maintenance of Permanent Permanent Lifting Equipment Equipment and Lifting Devices Devices Permanent lifting equipment and lifting devices shall be regularly inspected and maintained during operation and maintenance periods to eliminate accidents due to the corrosion of beams and bolts, deterioration of wires ropes, etc.

8.

Maintenance for Air-Cooled Exchangers (AFC) The following maintenance considerations apply to AFCs. •

Alignment of the fan and drive unit.

•

Lubrication and greasing.

•

Replacing the bolted bonnet.

•

Plugging the tubes.

•

Cleaning the tubes including external washing apparatus.

•

Removal of fan and drive unit for repair repair and replacement.

It is rare for the AFC tube bundles to be replaced except for very corrosive service. Therefore, this work is treated as a special maintenance operation to be made by using a large mobile crane. An additional maintenance access extended to closed to the AFC’s for a mobile crane is not required for this work and roads around the process units should be used for such maintenance.

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9.

Removing motor/pump In principle, motors for machinery and valves are inspected and repaired at a maintenance shop or a factory. The following provisions shall be considered for motors: •

Access for a forklift or a mobile crane to pick up the motor/pump.

•

A lifting device if there is no access for a forklift or or crane. crane.

•

For large motors, such as for a compressor in a shelter, shelter, the motors shall shall be removed from the side of the shelter by pulling them out with a crane or winch. The motor shall have temporary support and a sliding device underneath it such as pipe rollers. Large motors should be placed outdoors at the maximum extent possible to lift by a mobile crane.

•

For any pumps and and motors inside shelter will will be provided with lifting davits.

•

Access for others.

•

Access required for scissors lift mobile mobile type, for lighting.

•

Solar panels will need routine cleaning, then access is required. required.

•

For cable installations access access required for additional cable pulling pulling on racks below floor, etc.

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8

PIPE ROUTING •

Piping shall be routed to provide a simple, neat and economical layout with adequate flexibility and allowing for adequate support.

•

Expansion of piping should be accommodated wherever possible by the natural flexibility of the pipework. If necessary the route of the piping should be modified, or expansion loops should be incorporated, to obtain sufficient flexibility.

•

Piping shall be routed to provide a common point of support where possible.

•

Piping shall be designed and supported allowing valves and equipment to be dismantled or removed, without requiring temporary supports or the removal of piping other than designated removable spools.

•

Insulated removable spools shall be equipped with suitable lifting lugs.

•

Equipment piping shall be arranged to provide sufficient headroom and clearances for operation and maintenance. Detail for equipment piping design, section 8.0

•

Piping shall be arranged and supported so that blinds required for maintenance can be readily installed.

•

Piping shall be arranged to allow control valves with ring joint flanges to be removed without damage to the valve, flange or connected piping.

•

Piping shall be run at all times so as to avoid pockets.

•

Piping carrying safety services (firewater, hydraulic fluid) shall be routed to minimize the possibility of blast or fire damage rendering the respective system inoperable.

•

Piping shall be kept clear of escape routes, access ways, lay down and maintenance areas, manholes, access openings, inspection points, hatches, davits and areas required for instrument withdrawal.

•

Where required, the distance between pipes shall be increased to allow for movements caused by expansion. Sufficient space shall be provided between adjacent lines to prevent the lines (including insulation) from touching adjacent lines, electrical conduits or structures due to expansion or contraction.

•

•

The distance between pipes shall allow for the turning of a spectacle blind, if present. For the minimum clearances to be provided in the design and layout of piping refer to “Specification for Plant Layout and Spacing” (Document No: (Project Name Code)-.....-.....PI-SP-.....).

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9 9.1

PIPING SYSTEMS DESIGN PROCESS PIPING a.

Sample connections, corrosion probes, chemical injection connections, etc, shall be provided as shown on the P & ID’s.

b.

No cast iron pipe or piping components shall be used in hydrocarbon services.

c.

Unions in hydrocarbon service are not permitted; in all cases flanges shall be used. Refer to piping material class for details.

d.

Where a line with a lower pressure rating connects to a line or equipment with a higher pressure rating, the line will take the class of the higher rating, up to and including the first block and check valve, or up to and including the second valve when double block valves are used.

e.

Hydrocarbon lines passing through safe areas should be of a fully welded construction.

9.2

PRESSURE RELIEF PIPING a.

All process – relief valves and relief regulators shall be piped to a flare system, or other disposal system as indicated on the P & ID.

b.

Relief valves discharging to atmosphere must be provided with a pipe stack ending at least 3 m above any platform within a 7.5 m radius. Provide a 6 mm weep hole in bottom of stack to prevent liquid accumulation.

c.

Pressure relieving systems shall be designed in accordance with API RP 520 (Parts I and II) and API RP 521.

d.

The relief device may be placed either on top of vessel, or on main line connecting piping if that piping is adequate as relief valve inlet piping per API RP 520 part II.

e.

Flare headers shall contain no pockets, and shall be sloped to the flare drums with a slope of minimum 1: 1000.

f.

Relief device and discharge piping shall be higher than the flare header and shall discharge down into the header. Discharge piping shall be designed so that no liquid traps exist. However, sub-header located lower than a main header is allowed for gas

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services either with a drain pot or steam tracing up to the highest point of the subheader.

g.

Relief valves shall be located to permit testing and removal from floor level or from a fixed platform.

h.

Discharge piping shall not be smaller than the safety or pressure relief valves outlet, and shall be supported independently from the safety valves.

i.

Relief valves discharging to flare headers shall have blocks upstream and down stream when a spare relief valve is provided. A bypass valve will be provided when required for use in purging or venting equipment and systems.

j.

Reducers on relief valve inlet and discharge piping shall be located in the minimum distance from a relief valve. However, block valves with the same size as the relief valve connections will be located between reducers and the relief valve, if pressure drop consideration permit. Bleeder valve shall be provided between the inlet block valve and the relief valve where the inlet piping is 2 inch and larger.

k.

When dynamic loading may be expected due to discharge from relief valves generating pulsating flow, high velocity flow, flashing liquids, pressure conditions, or mechanical vibrations, the piping shall be carefully designed and checked to ensure that the pipe size, configuration, mechanical strength, supports and restraints will prevent excessive stresses, loads and vibrations.

9.3

INSTRUMENT AIR a.

Instrument air piping shall be designed and routed to minimize low pockets and dead ends. A drain valve shall be provided at unavoidable low points in the header.

b.

Branch connections shall be taken from the top of the header and each shall be provided with an individual block valve, in accordance with the P & ID’s.

c.

A block valve shall be located in the horizontal run at the high point of each branch line and in the lead to each individual instrument.

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d.

Air distribution piping shall be arranged with headers and sub-headers such that the system covers all location of air users, as advised by the instrument group.

e.

The extent of supply by the piping group, for instrument air systems, shall be the outlet of the branch isolation valve, which will be supplied with a screwed plug, at the distribution header or sub-header. Continuation of supply from the branch isolation shall be by the instrument group.

f.

Where large high – speed valve actuators are employed, distribution pipe size shall be checked with instrument engineers.

9.4

DRAIN SYSTEMS 9.4.1

OPEN DRAIN a.

The open drain system shall be in accordance with civil specification No: (Project Name Code)-.....-.....-CI-SP-..... “Specification for Road, Pavement, Sewage, Drainage and Fence”.

b.

Each open drain shall have a liquid seal.

c.

Only equipment drains specifically designated on the P & ID shall dump in to the open drain system.

9.4.2

CLOSED DRAIN

a.

Closed drain headers shall be piped to the closed drain sump with a minimum slope of 1: 500.

b.

Closed drains shall service all items of equipment from which solvent of hydrocarbons may be drained. This will include vessels, tanks, pump cases, and heat exchangers.

c.

Only drains specifically designated on the P & ID shall dump into closed drain system.

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d.

Closed drains where indicated on P & ID shall serve instruments such as level gages, level controllers and level switches, which require draining for normal operating and maintenance.

9.4.3

STORM SEWERS

a.

The entire plant area shall be under-laid by a system of storm sewers and concrete culverts. All surface area of the plant not drained by area drains shall be graded and sloped to drain to the storm sewers.

b.

Design, layout, sloping and installation of the storm sewer system shall be an integral part of the site development and grading plan.

c.

For further requirements for the design and installation of storm sewer, see Civil and “Structural Design Criteria “ (Project Name Code)-.....-.....-CI-SP-.......

9.4.4

AREA DRAINS

a.

Area drains for the plant shall be in accordance with Civil and Structural Design Criteria “(Project Name Code)-…..-…..-CI-SP-…..”.

b.

All building gutters and down-spots shall drain directly to storm sewers, by passing the area drain systems.

c.

Compressor and pump building floor drains shall connect to the area drain system.

9.5

Fire Water System a.

All fire water piping shall conform to specification No: “(Project Name Code)-…..-…..LC-SP-….. “Fire Fighting and Suppression Design Basis”, and the individual piping material

as

per

specification

No:

“(Project

Name

Code)-…..-…..-PI-SP-…..

“Specification for Piping Material Class”. b.

All fire water piping will be buried to the extent possible, see specification No: “(Project Name Code)-…..-…..-PI-SP-….., “Specification for Under Ground Coating Wrapping”.

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c.

Block valves in underground firewater lines shall be designed and installed as follows: •

The valves shall be installed in reinforced concrete boxes of sufficient size to permit access to servicing.

•

The boxes shall have suitable covers. The valve stems shall be provided with enclosed extensions to permit them to be operated from above grade. A valve position indicator shall be installed above grade to indicate full open and closed positions.

•

Above ground portions of the box, valve hand-wheel, and stem extension shall be painted with red point. Valves shall be properly identified by metal tag or assign to indicate the area served.

d.

Block valves on above ground fire water lines shall be designed and installed as the normal non operating valves.

9.6

Utility Stations a.

Utility hose stations consisting of water, air and nitrogen where required, shall be located to provide coverage for the operating area of each process unit within a 30 m radius from each station of grade and within a compressor shelter. In addition, air hose connection shall be provided at elevated structures where air driven tools will be provided. The detailed assembly of utility station shall be submitted for company approval.

b.

All utility hose connections for servicing equipment shall be as indicated on the P & ID.

c.

Utility station shall be installed from separated headers so that they remain in operation during a unit shutdown.

9.7

Sample connections a.

Valve sample connections shall be installed at points required for plant operation to facilitate plant test as indicated on P & ID.

b.

Sample connection assemblies shall be in accordance with detailed sheets.

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9.8

Heat Tracing Heat tracing shall be provided only as indicated on the P & ID. Details of heat tracing must be submitted for Company approval.

9.9

Potable Water The potable water system shall be isolated from all other systems. Potable water shall serve only drinking fountains, safety shower-eyewash, lavatory, toilet and change room facilities.

9.10 Emergency shower and eyewash fountains a.

Emergency showers and eyewash fountains shall be installed where there is a risk of the plant operators coming into contact with hazardous fluids.

b.

All emergency showers and eyewash fountains shall operate on potable water; the water pressure and temperature shall be controlled to prevent injury to users.

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10 EQUIPMENT PIPING DESIGN 10.1 Vessel Piping a.

Unless specifically required and shown on the P & ID, block valves are not required at process vessel nozzles. In case of emergency shut down valve(s) shall provided. The valve shall be installed in the line horizontally as practically close to the vessel nozzle, with the consideration of the reliability, operability, and maintainability.

b.

Where P & ID shows that valve(s) have to be located directly against the process vessel nozzles, but in case physical interference will occur for example, bottom outlet valves from vessels with skirts, the vessels may be located outside of the skirts for proper operation or maintenance of the vessels. (No flanges or valves including drain valve, may be located inside vessel skirt.)

c.

In general, valves shall be located directly against the nozzle or flammable liquid or liquefied gas service unless approval for exception is obtained. Valves shall be steel, and fire–safe if ball type.

d.

Normally no valves are used in re-boiler piping, or tower transfer lines. Provide valve in such piping only when shown on the flow diagram.

e.

Piping shall be arranged and supported so that temporary spectacles or blinds and spacers can be readily installed at vessel nozzles, unless there is a suitable location for inserting a temporary blind for isolation.

f.

Piping which requires supporting at or near a vessel shall preferably be supported from brackets attached to the vessel shell near the vessel nozzle.

g.

Inlet piping and nozzles shall be oriented to avoid impingement of inlet streams on the vessel wall, or against liquid level controller and gage glass connections.

h.

All vessels which require numerous level gages, level controls, level alarms, etc., shall be provided with a “standpipe” for mounting these devices. When shutdown devices are required, they may be installed on the same standpipe with control and alarm instruments. In hot and cold services, provisions shall be made as necessary for thermal expansion of the standpipe.

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i.

Instruments shall be individually valved to permit maintenance of each instrument. In general, instrument process connection valves shall be as specified in applicable individual piping material class.

j.

Instrument piping shall be provided with vent or drain facility to release pressure and fluid to permit instrument removal for maintenance purpose, if the instrument has no facilities.

k.

Pressure gage and liquid level gage connections on all valves or standpipe shall be oriented so that the instruments face the main operating aisle. Manual drain valves, when provided, shall be located so that an operator can observe the liquid level gage while manually adjusting these valves.

l.

Valved vents with plug or blind shall be provided at a high point for each vessel. The vent connection may be located on the adjacent piping if it is not suitable to provide a vent connection on the vessel.

m. Vents shall be of adequate size to allow venting the vessel without pulling a vacuum.

n.

Valved drain shall be provided at a low point for each compartment in all vessels. The drain connection may be located on the liquid outlet piping, upstream of the first block valve. However, if such outlet connection is not located on the low point of the drum or projects inside the vessel, a separate drain connection shall be provided. Drain arrangement shall permit complete drainage without internal pressure assistance.

10.2 Heat Exchanger piping a.

Heat exchanger piping shall be designed and supported so those channel covers and tube bundles can be removed with minimum dismantling of connection piping. Piping arrangement shall not be located at tubes bundle-removing area.

b.

In general all streams which are to be heated should preferably enter at the bottom of the exchanger, and streams to be cooled should enter at the top of the exchanger.

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c.

Process piping to and from kettle or thermal siphon re-boilers shall be as simple and direct, as thermal expansion analysis will allow.

d.

Piping shall be arranged for equal flow through parallel flow exchangers or sectioned air-cooled exchangers or cooler boxes. Inlet and outlet headers must not be located over and under the tubes area of air cooler heat exchanger.

e.

A ¾ inch minimum size thermal relief valve shall be installed on the cooler side of all shell and tube exchanger which are so connected that the cooler side can be closed off full of liquid while the hot fluid continues to enter the other side of the equipment for on-stream maintenance during operation. However, no thermal relief valve shall be provided on a water line of water coolers unless in-service maintenance is expected. A relief valve shall also be provided on the low pressure side of each exchanger if a leak from the high pressure side would cause the design pressure of the low pressure side to be exceeded. Thermal relief valves shall have a block valve on the inlet side for isolation.

f.

In case shell and tube exchanger are located 4 meter or more above grade, and if valves or valves arrangement have to be located close to the nozzles, it shall be provided with operating platform with removal handrail. Temporary platform for maintenance will be provided during maintenance, if necessary.

g.

Valved vent and drain connections shall be installed on both the tube and shell sides of each exchanger at high and low points respectively, when inlet and outlet valves are provided. Vents and drains may be in piping between the exchanger and inlet and outlet valves.

h.

Drain connections shall be 1-1/2 inches (minimum) for shell and tube and 1 inch for air cooled exchangers and concentric pipe exchangers. Drains for chemical services shall be piped to a drain system as specified on the P & ID.

i.

Heat Exchanger Thermowells

j.

Thermowells shall be provided for inlets and outlets when required for monitoring process stream temperature or for checking performance of heat exchangers, and shall be located in adjacent the nozzle.

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k.

The valves or piping arrangement shall be arranged around the heat exchangers, taking into consideration maintenance including disassemble of covers and removal of tube bundles.

10.3 Pump Piping 10.3.1

GENERAL a.

Piping shall be arranged and connected in such a manner to minimize a number of fittings that must be disconnected for pump maintenance.

b.

In manifolding two or more pumps to a common suction or discharge header, valving should be at hand height near pump nozzles to avoid chain operator, except where material in headers may congeal or freeze in dead end, then valves must be located so as to prevent dead end cooling while spare pump is not in operation. Where pumps are connected with common headers, any likely variation in piping temperature due to spare equipment not operating shall be considered.

10.3.2

PUMP SUCTION PIPING

a.

Pump suction lines shall be arranged as short direct as possible, still providing flexibility and support to minimize pipe loads at pump nozzles. Double suction pumps require a straight section of piping five (5) times the pump suction nozzle size.

Suction piping should be designed to avoid high pockets, especially for saturated liquid services. If a pocket is an avoidable, a proper venting line shall be provided at that high point. For pumps handling volatile liquids such as LPG, the vent connection shall be connected to a suction vessel without pockets.

b.

Where reduction in the pump suction line size is required, it will be located upstream of a suction valve if pressure drop and NPSH consideration permit. Eccentric reducers with the straight side up shall be used in horizontal suction lines to avoid forming an air pocket. A drain valve shall be provided if a low pocket is formed in this arrangement. Reducers located in vertical suction lines should be concentric.

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c.

Permanent strainers shall be provided on pump suction lines for fouling services or services handling fluids that may contains solid such as coke. All internal parts of permanent strainers shall be of corrosion resistant material suitable for the service and shall be designed to withstand the pressure forces resulting from blocked mesh. The open area of the screen shall be at least 2 times the internal pipe area. Permanent area strainers shall have a pressure tap located downstream of the screen element.

Temporary startup strainers using stainless steel mesh shall be provided in pump section lines, except where permanent strainers are provided. The strainer area for temporary strainer shall be at least 1.5 times the internal pipe area and shall be mesh screen backed up by perforated metal. All startup strainers may be removed after piping is free of debris.

Strainers shall be located between the pump and the first block valve, as close to the pump as possible. Piping shall be designed so that strainers can be removed or installed without springing the pipe.

The type of strainer shall be selected considering economics, piping arrangements, easy handling during use, etc. strainers shall have a visible handle tagged “Screen” and mesh size.

d.

Pump suction piping shall be supported with adjustable pipe supports located to avoid the need of temporary support during pump removal, preferably supported directly from the pump foundation block.

e.

A pressure/ temperature rating of suction piping shall basically be decided based on design conditions of the suction side. When a spare pump is provided and a pressure/ temperature rating of suction pipe is lower than that of discharge piping, the rating of piping between a suction valve including the valve itself and a pump suction nozzle shall be decided considering overpressure due to inadvertent closure of the suction valve.

It should be noted that as standard operating practice, spare pumps should be in a standby condition with liquids filled in the pump and with the suction valve open. Overpressure by as much as 33% above the service limit of a pressure/ temperature rating of suction piping is allowed. If over pressure exceeds 133

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percent of the service limit, a pressure/ temperature rating of the suction side shall be decided as follows: 1. When a pressure/ temperature rating of discharge piping is class 300 and lower, and the size of a suction pipe downstream of a suction valve is 12” and smaller, the pressure/temperature rating of the suction side is same as that of the discharge side. 2. When a pressure/ temperature rating of discharge piping is class 300 and lower, but the size of a suction pipe downstream of a suction valve is 14” and larger, the pressure/ temperature rating of the suction side is that of the suction piping upstream of the suction valve. 3. When a pressure/ temperature rating of discharge piping is class 600 and higher, the pressure/ temperature rating of the suction side is that of the suction piping upstream of the suction valve.

For case (2) and (3), above the suction valves shall be locked open in order to avoid overpressure caused by leakage through discharge and check valves, or flow through a check valve bypass if the suction valve is closed.

10.3.3

PUMP DISCHARGE PIPING

a.

A shut off valve shall be provided in the discharge piping. The size of valve is the same as the pump discharge nozzle when pressure drop consideration permit.

b.

A check valve shall be provided in the discharge piping of each centrifugal pump between the pump and the shutoff valve. Where the possibility of the hydraulic shock exists, a non-slamming type check valve shall be used, and support loadings shall be checked. For plunger pumps, the discharge check valve shall be block valve size and of the piston type.

c.

When a spare pump is provided, a small line bypassing a discharge check valve, called a warm-up or cool-down bypass, shall be provided for the following services: 1. Where the operating temperature exceeds the criteria given by the mechanical engineers. 2. Where process fluids will solidify become too viscous or freeze at atmospheric temperature.

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3. Where the operating temperature is less than 0 ºC. 4. Where handling fluids having a high vapor pressure at an ambient temperature such as LPG pumps.

This bypass line is connected between the pump discharge nozzle and the line downstream of the check valve. If pumps are of multi-stage type, have a large casing, or are of top-top type, then bypass line should also be connected to the bottom casing drain nozzle upstream of a casing drain valve according to the vendor’s instruction.

10.3.4

PUMP VENTS AND DRAINS

a.

All pumps except for self-venting pumps shall be equipped with high point vent valves preferably at the top of the case or cylinder.

b.

All pumps shall be equipped with drain valves installed preferably at the bottom of the case or cylinder but in any event at appoint that permits complete liquid removal.

c.

Discharges of vents and drains shall be routed as indicated on the P & ID.

d.

A closed drain shall be provided between the block and check valves in lines containing highly corrosive or toxic fluids

10.3.5

PUMP INSTRUMENT CONNECTIONS

A pressure gage connection shall be provided on discharge of all pumps. A suction pressure gage shall be located downstream of the permanent suction strainer.

10.3.6

ACCESS TO PUMPS

Piping at pumps and turbines shall be arranged to avoid interference with operation or maintenance access. Removable spool piece shall be provided as appropriate, such as at end suction pump inlets, to permit maintenance without major piping disassembly.

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10.3.7

WEIGHT AND THERMAL STRESS Suitable supports or anchors shall be provided so that excessive weight and thermal stresses will not be applied to the casings. Careful design consideration shall be given to piping configuration to minimize these stresses.

10.4 Compressor Piping 10.4.1

GENERAL a. Compressor piping shall be installed to minimized pulsation, in keeping with good industry practice. Particular consideration shall be given to design of piping subject to vibration from dynamic loading associated with reciprocating compressors. Vendor will provide volume bottles.

b. Suction and discharge piping will run on sleepers at grade, if at all possible. This arrangement permits simple and effective supports of the lines to reduce vibration, particularly on reciprocating compressors. Suction and discharge piping shall be fitted with removable spools located at the compressor nozzle for ease maintenance.

c. Compressors headers and laterals and other piping subject to vibration shall be anchored and guide with pipe clamps. Tee beam support shoes welded to the pipe shall not be used on compressor piping subject to vibration.

d. Headers shall have provisions for future compressor additions if such additions are expected.

e. Lead lines shall be designed as follows: •

Block valves shall be installed outside of the compressor building or enclosure and shall be located only in horizontal piping.

•

Suction block valves shall be line size and shall be full bore.

•

In compressor piping systems containing bypass between discharge and suction or where backflow is possible, pipe, valves and fittings on the suction side downstream of the block valve, and including the block valve, shall have the same pressure rating as that on the discharge side.

•

Pressure relief valves shall be installed in all discharge lead lines upstream of the discharge block valve of the reciprocating and screw compressors.

•

Spectacle blinds will be installed on compressor side of lead line block valves in multiple compressor installations.

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10.4.2

Compressor piping shall be cleaned.

CENTRIFUGAL COMPRESSORS a. Where a centrifugal rotary or screw compressor takes suction from a header, the lateral should be connected to the top of the header. Any unavoidable low points between the header and compressor shall be provided with automatic drain.

b. Temporary strainers should be provided in the suction, located as close as practicable to the compressor inlet and mesh size shall be approved by manufacturer. Differential pressure connections shall be provided upstream and downstream or the strainer for installation of a temporary gage.

c. A quick response check valve with dual plates and center of percussion stop shall be installed as close to the nozzle as feasible damage during surge condition and to prevent back flow during emergency in the discharge of centrifugal compressors connected to a system where backflow through the compressor is possible.

10.4.3

RECIPROCATING COMPRESSOR PIPING

a.

All reciprocating compressor piping shall be analyzed on an AGA approval acoustical analog simulator to optimize piping design for minimum pulsation.

b.

Reciprocating compressors shall have pulsation dampeners, either of a proprietary design or a standard volume chamber for each cylinder.

c.

The pulsation dampeners shall not be used as a knock out drum.

d.

Permanent strainers should be provided in the suction, located as close as practicable to the compressor inlet. Differential pressure connections shall be provided upstream and downstream of the strainer.

10.4.4

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COMPRESSOR VENTS AND DRAINS

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a.

All suction and discharge (lead) lines shall have ¾ inches minimum valve drains installed between the compressor and the lead valves and the headers, unless the leads will drain to the headers by gravity.

b.

10.4.5

All headers shall have drains at each end.

COMPRESSOR INSTRUMENT CONNECTIONS

Connection for temperature and pressure indicator shall be provided upstream and downstream of each compressor stage. Suction pressure gages connection shall be located downstream of the suction strainer.

10.4.6

STRAINERS

a.

Strainers shall be installed in such away that they may be removed without springing the pipe, and shall not be in the up-flow position.

b.

The strainer shall be mesh stainless screen backed up by perforated metal and shall have a visible handle tagged “Screen” and the mesh size. The area shall be at least 2 times the internal pipe area.

c.

All startup, strainers may be removed after piping is free of debris, with Company’s approval.

10.5 Fired Equipment Piping a.

Fuel gas piping shall be arranged for equal flow to each burner and to allow for removal or individual burners. All piping shall be routed to avoid blocking access to observation opening and tube removal areas.

b.

Burner manual control valves shall be located so they can be operated while observing fire through observation ports. Flexible hoses may be used between manual control valves and connection to burners to absorb vibration and simplify disconnection.

c.

Emergency shutoff valves in fuel gas supply headers shall be located at a safe location remote from the fuel users.

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d.

Fuel gas piping shall be provided with knock out pots at ends of headers to prevent condensate from reaching fuel gas burners. Condensate shall be drained off and disposed of in a safe manner.

e.

Manifolds for heater-snuffing steam shall be located not less than 15 m from heater, and preferably in the direction of the control room.

f.

Multi-pass heaters shall have the inlet and outlet piping arranged symmetrically to ensure uniform distribution.

10.6 Filter Piping a.

All filters shall both be spared, or provided with block and bypass valves.

b.

Where bypass valves are provided, the piping shall be designed to prohibit sludge, fines, or other debris from accumulating in dead piping upstream of the bypass valve.

c.

Filters serving individual equipment items which can be taken out of service due to equipment sparing need not have block and bypass valves (example – turbine fuel gas filter serving only one turbine)

d.

Differential pressure gage connections shall be provided upstream and downstream of the filter.

10.7 Storage Tank Piping a.

Piping connected to storage tanks shall have sufficient flexibility to compensate without damage for possible tank settlement.

b.

Piping at grade in storage tank area shall be at least 300 mm clear above grade level to allow for inspection, painting, etc.

c.

Piping through earth dikes shall be coated and wrapped through the dike and 150 mm beyond of each slide.

d.

Piping through concrete fire walls shall be installed through sleeves of a size to pass flanges. The pipe within the sleeve shall be coated and wrapped and the annular space shall be filled with removable packing.

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e.

Fill lines to storage tanks containing flammable liquids shall not be connected overhead.

f.

Piping connected to the tank except nozzles for temperature indicators, propeller mixers and overflow and other connections on the roof shall be valved as close as to the tank as possible. Flanged valves shall be directly connected to the tank nozzles.

11 PIPE SUPPORT DESIGN a. Pipe supports shall take account of the insulation requirements for the piping.

b. Main pipe supports shall generally be spaced at 6m centers, maximum. If the

calculations show less than 6 m interval, then the result of calculations shall be followed. The deflection shall be considered that the line is full of water and that all valves, insulation and other loads are imposed.

c.

Pipe size 2” and smaller ->

maximum deflection: 10 mm

Pipe size 3” and larger

maximum deflection: 15 mm

->

Pipe supports for all critical lines shall be designed based on the loads calculated from the piping stress analysis.

d. As far as possible, standard pipe supports shall be selected. For non-standard pipe

supports, individual pipe supports shall be designed and special support details shall be generated.

e. Spring supports shall be used, if required, to accommodate vertical pipe displacements

while controlling dead weight reactions.

f.

Piping shall not be supported off other pipes, unless when supporting drain valves from major lines.

g. Anchors, guides and hangers shall be used to control movement caused by expansion,

contraction and vibration.

WORK SEQUENCE

70 of 71

Rev. A

Work Sequence for Piping Planning & Design

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