Guidelines on Dometic Gas Piping System

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Guidelines On Domestic Gas Piping System

Disediakan oleh: Jabatan Keselamatan dan Pembekalan Gas Suruhanjaya Tenaga Tenaga Prepared By: Department o Gas Saety and Supply Energy Commission

Diterbitkan oleh/Published by: Suruhanjaya Tenaga (Energy Commission) Tingkat 13, M enara TH Perdana 1001 Jalan Sultan Ismail 50250 Kuala Lumpur Tel Tel : 603-2612 5400 Fax : 603-2693 7791 Email : in[email protected]














PURPOSES These guidelines describe saety requirements in the design, construction, operation and maintenance o uel gas piping and utilisation systems. The requirements are based on applicable legislation and industry standards. The guidelines are intended primarily to guide developers, consultants, contractors, owners and operators o piped uel gas installations in residential premises, and to educate end-users and the public on uel gas saety principles and practices.

CONTENTS

SCOPE These saety guidelines apply to the ollowing piped uel gas installations in residential premises:

Purposes

23

Gas metering (a)

liqueed petroleum gas (LPG) (LPG) storage storage tanks or cylinders and piping ping systems systems up to end-user end-user appliances. ances.

Scope

24

Pipe sizing

(b)

natural gas area stations and piping systems up to end-user appliances.

1

Characteristics o piped gas

25

Pipe installation

These guidelines are not intended to cover in detail all the saety and technical requirements or the uel gas installations

3

Gas piping system confguration

35

Pipe jointing

6

Legal requirements

36

Gas appliance selection

8

Planning or piped gas system

37

Gas appliance installation

9

Gas demand determination

39

Inspection, testing and commissioning

11

Design pressure

41

Operation & maintenance

13

Pressure regulation

43

Recommended preventive maintenance

14

Material selection

15

LPG storage sizing

16

LPG storage saety

22

Pipe isolation

as mentioned above. For urther details on the subject, reerence should be made to applicable regulations and standards mentioned in these guidelines.

programme or gas piping systems

44

Related standards and codes o practice or gas piping system

46

Conversion table

ii

iii




1

1.1

CHARACTERISTICS OF PIPED GAS

The two types o uel gases that are normally piped or reticulated to end-users are liqueed petroleum gas (LPG) and natural gas. Their components and characteristics that have an implication implication on the saety o the installations are described below : Table 1: Gas properties

Physical Properties O Methane, Ethane, Propane And Butane Proper ties

Methane

Ethane

Propane

Butane

CH4

C2H6

C3H8

C4H10

.3

.4

.509

.582

Chemical Formula Specic Gravity (Liquid) Boiling Point °C

-164

-89

- 42

- 0.5

Ignition Temperature °C

620

515

510 – 600

480 - 540

Flammability Limits (Upper) %

16

12.5

9.50

3.50

Flammability Limits (Lower) %

4.0

3.0

2.15

1.55

Ideal Combustion Ratio (A (Air To Gas)

10 to 1

15 to 1

24 to 1

31 to 1

Heat Value Per Cu.Ft (Vapor) Btu

1.000

1.600

2.516

3.280

-

-

21,591

21,221

Heat Value Per Pound (Liquid) Btu

1.2

Liqueed petroleum gas (LPG) •

LPG is a mixture o propane (30 - 40%) and butane (60 - 70%) LPG is stored as a liquid under pressure, is colourless and odourless in its natural state

•

LPG vapour is heavier than air. Thereore, the vapour may ow along the ground and into drains and be ignited at a considerable distance rom the source o leakage

•

LPG orms a ammable mixture when mixed with air within the ammability limit to large volumes o vapour/air mixture and thus cause considerable hazard

•

1.3

LPG is odorised beore distribution, such that any escape o gas may be noticeable by its smell

Natural gas •

natural gas is mainly methane

•

natural gas is not stored at the consumer’s premises due to complexity o storage acilities. Natural gas can only be easibly liqueed under cryogenic conditions

•

•

natural gas is lighter than air. Hence, escaping vapour rises upwards natural gas orms a ammable mixture within ammability limit when mixed with air in the correct proportion

•

iv

natural gas is odorised beore distribution

1




2

1.4

Basically, saety requirements in the design, construction and maintenance o either LPG or natural gas piping

2.1

GAS PIPING SYSTEM CONFIGURATION

LPG piping system

systems at consumer’s premises are the same, except in the ollowing aspects which necessitate dierent 2.1.1 The main components o the sys tem are:

design principles to be used. 1.41

2.1.1.1

Due to its very low boiling point, natural gas is transported in pressurised vapour state rom gas

Storage vessel

processing plants or terminals via pipelines to end-user appliances. There is no natural gas storage at the consumer’s premises. LPG, due to its relatively higher boiling point, is transpor ted by road tankers

LPG is stored at consumer’s premises in pressurised vessels (or bulk storage systems) or

in the liquid state rom reneries or terminals and stored at consumer’s premises in storage vessels

in cylinders, which are maniold together. The design pressure o the vessel or cylinder is

beore it is vaporised and piped to end-user appliances

usually 1725 kiloPascal (kPa) or 250 pounds per square inch (psig). Bulk storage vessels may be installed in any o the ollowing congurations:

1.42

Hence, in LPG systems there is a risk o liquid being leaked or released rom the system. Small volume

•

aboveground - tank is ully exposed aboveground

o liquid LPG leaks rom the storage system will expand to become an enormous volume o ammable

•

underground - tank is ully buried underground

vapour/air mixture, which may give rise to BLEVE (boiling liquid expanding vapour explosion). Since

•

mounded - tank is ully earth- covered above the ground

there is no natural gas liquid at the consumer’s premises, similar leakage o natural gas will give rise to 2.1.1.2

a much smaller volume o ammable vapour/air mixture 1.43 Natural gas vapour is lighter than air whereas LPG vapour is heavier than air. Any leakage o natural

Delivery or service pipeline This line is used or delivering the LPG vapour rom the storage tank to gas appliances.

gas vapour rom the piping system will tend to be easily dispersed and diluted upwards, whereas LPG

Vaporisers are sometimes installed near the tank to vaporise liquid LPG in the line into

vapour leaks rom the piping system will tend to accumulate to the surace below. Thus, preventive

vapour beore the rst stage regulator. This is used only in ‘liquid withdrawal systems’.

measures need to be incorporated in the design and operation o LPG systems to enhance ventilation 2.1.2 Pressure regulators are installed along the line to reduce the vapour pressure progressively rom the

and minimise leaking gas accumulation at lower suraces or depressions at the installation site

tank operating pressure about 414 414 – 690 kPa (60-100 psig) to appliance operating pressure 300 mm 1.5

LPG or natural gas by itsel has no toxicity. However, carbon monoxide (CO) is generated as the result o

w.c. (water column) or 0.5 psig. This pressure reduction is normally carried out in t wo stages (or

incomplete combustion. CO has extremely high toxicity and, in physical properties, it has essentially the

better reliability and saety) such that the gas line pressure in the building is reduced to not more

same relative density as air and, since it is also colourless and odourless, people hardly become aware o its

than 35 kPa (5 psig). A schematic showing a typical conguration o LPG storage and piping system

presence. Poisoning is caused by inhaling only a very small amount and it could result in death.

installed on consumer’s premises is as shown in g. 1 and g. 2.

Fig. 1 : LPG maniolded cylinders storage and piping system

2

3




Fig. 2 : LPG bulk storage and piping system

2.2

Fig. 3 : Natural gas supply system

Natural gas piping system

2.2.2 The pressure rom the main line is reduced at the city gate station to about 1700 - 2070 kPa (250-300 psig) and subsequently at district stations to 400 kPa (60 psig). The pressure is  urther reduced at area

2.2.1 Natural gas is transported  rom the gas processing plant to city gate by means o a main transmission

stations in residential complexes to about 300 mm w.c. (0.43 psig) beore the pipe enters the building

pipeline. Natural gas rom the main transmission pipeline is then reduced in pressure at the city gate

or urther reticulation to gas appliances. Reer to g. 3.

station and distributed to a district or city. In each district or city, urther pressure reductions are achieved at district stations and service stations or area stations beore reaching the consumer gas utilisation acilities.

4

5






3

3.1

LEGAL REQUIREMENTS

The saety and reliability o gas piping or reticulation systems in non-industrial premises are governed by

3.4

Competency o technical personnel and contractors who design, install construct, maintain, repair or operate

the Gas Supply Act 1993 (Act 501) and the Gas Supply Regulations 1997, under the purview o the Energy

piped gas systems are controlled under Act 501 through the registration o competent person and contractor

Commission (Suruhanjaya Tenaga). Act 501 regulates regulates the piping o natural gas downstream o the city gate

respectively.

stations or the piping o liqueed petroleum gas (LPG) rom the lling point o storage vessels or cylinders 3.5

up to end-user appliances or equipment.

Approvals are issued by Energy Commission to contractors beore commencing installation work and ater its completion. Engineering drawings, calculations, certicates o completion and test endorsed by the relevant

3.2

3.3

Gas is dened as ‘methane, ethane, propane, butane, or hydrocarbons which may consist o one or more

competent persons have to be urnished or the approval purposes. Gas ttings, appliances or equipments

o the above gases in the orm o gas or liquid’. Hence, all natural gas or LPG distribution, reticulation and

installed in piped gas systems must also be o the type approved by Energy Commission or other related

utilisation systems in the country are covered by the Act.

government agencies. 3.6

The design, installation, operation and maintenance o piped gas systems must comply with the saety requirements stipulated in the Gas Supply Regulations 1997 as indicated below Fig 4.

In line with the provisions o the Gas Supply Regulations 1997, saety and technical provisions prescribed by the ollowing standards are recognised by Energy Commission as a basis or reviewing and approving piped gas installations and equipment. 3.6.1 Malaysian Standards: •

MS 830 – Code o practice or the s torage, handling and transportation o liqueed petroleum gases. (The code covers the design, construction, location and operation o LPG storage and piping up to the outlet o the frst stage regulator)

•

MS 930 – Code o practice or the installation o uel gas piping systems and appliances. (The code is a saety code which applies to the installation o uel gas piping systems and appliances rom the outlet o the frst stage regulator (or LPG) or the customer’s meter set assembly (or natural gas) up to the gas utilisation device)

3.6.2 American Society o Mechanical Engineers Standards: •

ASME B31.8 – Gas Transmission and distribution piping systems (The code covers the design, abrication, installation, inspection, testing, and saety aspects o operation and maintenance o gas transmission ssion and distribution systems, including gas mains and service lines up to the outlet o the customer’s meter set assembly.)

Fig. 4 : Saety requirements requirements in the gas Supply Regulations 1997

3.7

Saety aspects o gas piping installed in premises dened as ‘actories’ by the Factories And Machinery Act 1967 (Act 139) are outside the scope o Act 501. They all under the jurisdiction o the Department O Occupational Saety and Health (DOSH).

6

7






4

4.1

PLANNING FOR PIPED GAS SYSTEM

5

When planning or designing the gas piping or reticulation system, the ollowing aspects must b e determined

5.1

GAS DEMAND DETERMINATION

The volume o gas accounted or should be determined rom either the manuacturer’s input rating, gas

or veried in advance in order to ensure the system meets all saety and technical requirements o the

supplier, equipment manuacturer or competent personnel. Estimation on equipment’s rating is as shown

legislation and standards as well as it is able to deliver the required quantity o gas:

below in Table 2 (source: rom Table 11, MS 930).

•

or natural gas supply systems, conrmation on the availability o gas distribution line inrastructure

Table 2 : Approximate gas input

and the required supply pressure must be obtained rom the licensed gas supplier •

Minimum Demand o Typical Gas Appliances in BTUs Per Hour

total gas consumption volume o gas appliances (maximum gas volume per hour) must be determined based on existing and anticipated uture appliance demands

Appliance

Demand in BTU/hour

•

consumption pattern o gas appliances (coincidence actor)

Barbecue (residential)

50,000

•

supply pressure required or the proper operation o the gas appliance

Domestic Clothes dr yer

35,000

•

the locations o gas appliances

Domestic Gas Range

65,000

•

suitable space or compartment in the housing area, building and users’ premises that is required or

Domestic Recessed Oven Section

25,000

Gas Rerigerator

3,000

Storage Water Heater up to 30 gallon tank

30,000

the gas piping system installation

•

the land or space in the housing area or building that is required or natural gas regulating station or LPG storage system, inclusive o parking or loading/unloading bay

Source : Tabl e 11 o MS 930 •

when an additional piping is to be connected to existing piping, the existing piping must be checked 5.2

to determine i it has adequate specications and capacity or a new demand

The total connected hourly load should be the basis or storage and pipe sizing or all equipment that may be operating at ull capacity simultaneously. However, a coincidence actor (CF) can be established and

•

sizing o piping to carry the maximum gas ow rate

may be used with the approval o Energy Commission (as per MS 930). Coincidence actor is the ratio o the maximum demand o a group as a whole to the sum o the individual maximum demands o the several components o the group. It is dependent upon the number and types o gas appliances installed. 5.3

A suggested statistical table or determining the coincidence actor or household units installed with gas cooking ranges and water heaters are as shown below in Table 3.

8

9






6

6.1

DESIGN PRESSURE

Piping systems need to have the required structural strength with a reasonable actor o saety to withstand primary stresses arising rom internal gas pressures as well as secondary stresses rom ex ternal orces. Besides

Table 3 : Coincidence actor or household

this, it must also be leak-proo to prevent inadvertent escape o the ammable and explosive gases to the

No. o units

Value o CF

No. o units

Value o CF

No. o units

Value o CF

1

1.0

15

0.225

100

0.152

2

0.680

20

0.209

150

0.143

3

0.538

25

0.198

200

0.138

surroundings. 6.2

In order to minimise the risk o gas leaks, in line with the requirements o MS 930 the maximum operating pressure o piping located inside buildings should not exceed 35 kPa (5 psig) unless approved by Energy Commission and one or more o the ollowing conditions are met: •

•

the piping system is welded. the piping is located in a ventilated chase or enclosed or protection against accidental gas accumulation.

4

0.453

30

0.190

250

0.134

5

0.395

40

0.179

300

0.132

6.3

The design pressure o LPG bulk storage vessels (aboveground, underground and mounded) and portable LPG cylinders should be 1725 kPa (250 psig). This is in line with MS 830 requirements (The normal operating pressure o LPG storage containers is 414-690 414-690 kPa (60-100 psig)).

6

0.353

50

0.171

400

0.128

7

0.320

60

0.165

500

0.126

8

0.293

70

0.161

600

0.124

9

0.271

80

0.157

700

0.123

10

0.252

90

0.154

> 1000

0.120

6.4

LPG storage containers have to meet the strength requirements o applicable Malaysia Standard or international standards such as ASME Section 8 and they require approval rom Department o Occupation, Saety and Health (DOSH). Piping and components specication have to comply with ASME B31.8, MS 830 830 or MS 930, whichever applicable.

6.5

According to ASME B31.8, the piping system should be designed to o perate at pipe material hoop stress levels below the yield strength o the pipe material. The saety ac tor to determine the operating stress level takes into account the risk o third party damages that is categorised by the code according according to its location Class. A location Class 1 reects minimum risk o third party damage whilst location Class 4 reects maximum risk. All distribution pipelines in the country are designed to operate under location Class 4 conditions.

Coincidence Factor (CF) however can also be determined by using Imperial Formula as stated below: 6.6

MS 830 requirements pertaining to the design pressures o sections o LPG piping systems are as ollows:

CF = 0.95 0.3

n

•

piping and components used at pressure higher than storage container pressure, such as on the discharge o liquid transer pumps must be suitable or a working pressure o at least 2410 kPa (350

where n is the number o units o specied premises

psig).

10

11






7

•

piping and components used with liquid LPG or with vapour LPG at operating pressure over 860 kPa

7.1 7.1

(125 (125 psig) must be suitable or working pressure o 1725 kPa (250 psig). •

PRESSURE REGULATION

Piping systems have to be installed with the necessary devices to regulate ow and pressure. Pressure regulators are installed or reducing the gas delivery pressure beore reaching the appliances.

7.2

piping and components or use with vap our LPG at pressure not exceeding 1725 kPa (250 psig) should be suitable or working pressure o 1725 kPa (250 psig).

In LPG systems, a high pressure regulator is installed at the LPG storage container outlet line or reducing the tank pressure o about 550 kPa (80 psig) to 35 kPa (5 psig) or less beore entering the building. When installed as such, the regulator is known as the rst stage regulator o the gas reticulation system.

7.3

A low pressure or second stage regulator is installed downstream o the rst stage regulator to reduce the 35 kPa (5 psig) gas pressure to about 300 mm w.c. (0.5 psig) outlet pressure, which is the normal operating pressure o LPG appliances.

7.4

Preerably, regulators regulators should be installed outdoors or saety reasons. When this is not possible, regulators installed inside buildings should be vented to the outside air, except venting is not necessary or regulators with Over Pressure Shut O (OPSO) with higher 20% higher setting (with built-in vent limiting devices).

7.5

A piping system must have at least t wo acceptable devices (a line pressure regulator regulator plus one other device), each limiting the pressure to a value that does not exceed the maximum working pressure o the downstream system, both o which must ail simultaneously in order to avoid overpressure the downstream system. It is thereore mandatory to have built-in pressure relie devices in the second or nal stage regulator to protect the appliances rom excessive pressures.

7.6

Pressure relieving and pressure limiting devices devices should be set, so that the pressure should not exceed a sae level beyond the maximum allowable working pressure or the piping and appliances connected.

12

13






8

8.1

MATERIALS SELECTION

9

Materials used in the construction o gas reticulation systems must be compatible with the properties o the

9.1

LPG STORAGE SIZING

The capacity o LPG storage tanks or maniolded cylinders must be determined such that enough gas is

gas. They must have the necessary properties such as good mechanical strength, ductility, resistance against

available to be piped to the appliances at all times. The tanks should be sized such that adequate pressure is

gas attack and environmental degradation. LPG and natural gas will cause natural rubber and some plastics

maintained to operate the gas system at the rated gas demand o the appliances. Tank Sweating[1] will occur

to deteriorate. Hence, installers and users should only use hoses and other equipment specically designed

when the container is undersized.

or these gases. 9.2 8.2

Malaysian Standards MS 830 and MS 930 clearly stipulate the list o materials acceptable or gas reticulation

In natural vapourization systems, the gas demand must be equal to or less than the vapourization rate o liquid LPG in the storage container at the worst operating condition. The rate o v apourization o a container is dependent upon the temperature o the liquid and the amount o wetted surace[2] area o the container.

systems as mentioned below.

The temperature o the liquid is proportional to the outside air temperature and the wetted surace area is 8.3

8.4

Pipe material should be steel, copper, or polyethylene and should comply respectively with the ollowing or

the tank surace area in contact with the liquid. Thereore, when the outside air temperature is lower or the

other equivalent specications approved by Energy Commission:

container has less liquid in it, resulting in a lower vapourization rate.

•

steel pipe: ASTM A106 or API 5L Grade B

•

copper pipe: EN 1057.

•

polyethylene pipe: ASTM D2513 or ISO 4437. Polyethylene pipes made to other standards should

9.3

It is necessary to maniold LPG cylinders or tanks to a common supply pipeline in order to obtain the required capacity or liquid vaporisation or to minimise cylinder replacement or tank relling requency (preerably a

include the ISO method o determination o long-term hydrostatic strength at 20°C derived rom

minimum o once in 7 days) or the installation. This entails the provision o operating and standby or reserve

80°C testing.

cylinder banks. 9.4

Carbon steel is the most commonly used piping material with no limitations o piping operating pressures due to its good mechanical properties.

Rules o thumb developed by the industry through experience may be used in sizing LPG storage cylinders. A recommended rule o thumb is that a 50 kg LPG cylinder has an evaporative capacity o approximately 100,000 Btu per hour.

8.5

Medium and high density polyethylene (PE) pipes may be used or buried installations with operating 9.5

pressures o not exceeding 414 414 kPa (60 psig).

To ensure uninterrupted supply o gas, automatic changeover regulators should be used. These regulators change rom the supply cylinder (when there is insufcient pressure) to the stand-by unit automatically

8.6

Copper pipes (seamless) may be used in vapour phase systems only with operating pressures o not

without having to shutdown the system to rell.

exceeding 140 kPa (20 psig). 9.6 8.7

8.8 8.9

Storage container evaporative capacity problem may be overcomed by reverting to liquid withdrawal using

Underground carbon steel vessels and pipes need to be protected rom corrosion by using protective

a LPG indirect-red vaporizer to vaporise the liquid LPG beore the rst stage regulator. The design and

coatings and cathodic protection system.

installation o various types o LPG vaporizers are covered by MS 830.

Pipe ttings should be steel, copper or polyethylene. Pressure containing metal parts o valves (except appliance valves), valves), including excess-ow valves, non return valves, saety relie valves, and manual shut o valve used in piping systems, should be o steel, ductile (nodular) iron, malleable iron or brass.

8.10

Steel should meet the requirements o ASTM A182. Ductile iron should meet the requirements o ASTM A395 or equivalent. Malleable iron should meet the requirement o ASTM A47 or equivalent. All materials used, including valve seat discs, packing, seals and diaphragms should be resistant to the action o LPG under service conditions.

8.11

Cast iron is not permitted to be used as piping and ttings material material because o its brittle properties. PVC and

[1] watercondensation on external surace o containerdue to excessive loweri ng o temperature o LPG liquid in containerto meet demand

natural rubber are also not allowed due to their poor long-term resistance to gas attack.

[2] liquid in contact that spread overthe surace

14

15








10 LPG STORAGE SAFETY

A suitable site or the permanent placement o an LPG storage tank or maniolded c ylinders must be selected

Water capacity o individual container (kl)

to ensure saety o the installation. The ollowing actors should be considered: 10.1

Saety distance

Minimum saety distance (m) A

B

C

D

G

Up to 0.5

none

no

3

6

10

Over 0.5 to 2.5

1

4.5

3

6

10

H see 4.3.3.3

10.1.1

Saety distances are intended to protect the LPG acilities rom the radiation eects o res involving other acilities as well as to minimise the risk o escaping LPG being ignited beore being dispersed or diluted.

10.1.2

(d) in MS 830

Saety distances should be measured horizontally and radially rom the container shells to the

Over 2.5 to 10

1

Over 10 to 135

D1 + D2

specied eature (e.g. an adjacent storage container, building, and property boundary) except that

4

7.5

3

6

10

15

3

6

10

where deection or radiation walls are used, the distance should be measured in a horizontal line around such walls. 10.1.3

Fig. 5: Saety distance o aboveground aboveground bulk stroge container Source : Figure 2, o MS 830

The saety distance requirements or various types o tank installations are spelt out in detail in MS 830. A 4-hour re-rated deection wall o 2 meters height may be installed to reduce saety distance between storage vessel and buildings.

10.1.4

The saety distance requirements or ab oveground and underground/mounded tank installations at consumer’s premises as stipulated in MS 830 are included as ollows:

Water capacity o individual container (kl) Up to 135

Minimum saety distance (m) A 1.5

B 3

C 3

D 6

G 10

H See 4.3.3.3.(d) in MS 830

Fig. 6 : Saety distance o underground / mounded bulk storage containers containers at consumers premises (Underground (Underground and mounded tank installations oer more protection against surrounding res) Source : Figure 4, o MS 830

16

17








10.2

Site topography

10.6

Corrosion protection 10.6.1

To avoid accumulation o liquid or vapour beneath or in the immediate vicinity o a container, the container

Every buried container and pipeline should be protected against corrosion by protective coating

should not be situated in or vertically above a depression on the site, nor should the area under or around

or wrapping o enamels or plastic materials supplemented by an adequately designed cathodic

the container be lled with aggregate with a high percentage o voids. It should be located ar away rom

protection system.

underground and deep open drains to prevent leaking LPG vapour rom accumulating and owing to 10.6.2

sources o ignitions.

Cathodic protection is an electrical technique or imposing a p otential on the protected container or pipeline to counter the tendency or electrochemical ion migration an d stop corrosion almost

10.3

Security and damage protection

completely. The cathodic protection system may be o the sacricial anode or impressed current type but in either case should be provided with a point at which a test can be made to determine

10.3.1

The storage acilities installed at site must be adequately protected against tampering by

the efcacy o the system.

unauthorised persons. This is usually achieved by providing security security encing on the acilities. 10.7 10.3.2

Backlling

The storage and piping s ystem must also be protected against possible damages rom encroaching vehicles by installation o barriers or walls whenever required.

Backlling material immediately adjacent to underground/mounded container should consist o at least 150 mm o non-corrosive inert material such as water-washed sand, ree rom soil, rocks, gravel or ashes and other

10.4

Accessibility

deleterious matter. Backlling sand should have a minimum resistivity o 100 Ω when tested ater thorough moistening with distilled water. The sand should be well padded into place during the backlling operation.

Storage acilities need to be located where there is adequate provision o access and exit routes or gas

Mounded containers should have the upper surace covered with earth to a depth o at least 600 mm.

delivery tankers and also emergency equipment. Escape routes must also be provided or operating 10.8

personnel during emergencies. 10.5

Electrical and electrostatic hazard precaution 10.8.1

Ventilation

According to MS 830, an area classied as “hazardous” is an area in which any ammable atmosphere is continuously present (Zone 0), or is likely to occur in normal operating conditions (Zone 1) or

10.5.1

Storage acilities must have good natural ventilation to ensure sae dilution o leaking gas.

10.5.2

A typical layout plan o a LPG bulk storage acility with saety distance, security and damage

so that a xed ignition source does not all within a hazardous area classied as Zone 0, 1 or 2

protection and good accessibility or relling is as shown below.

surrounding the above points.

in abnormal conditions (Zone 2). A storage container and other specied gas equipment and handling acilities such as relie valve discharge, vaporisers and lling points should be located

10.8.2

Only intrinsically sae electrical equipment (equipment that cannot cause ignition when in contact with ammable or explosive atmospheres) can be used in Zone 0, whilst ameproo/explosionproo electrical equipment (equipment which contains the explosion within housing, preventing the ignition o the surrounding atmosphere) may be used in Zone 1 or 2.

10.8.3

An eective earthing point and/or bonding connection should be provided at the storage site or discharging static electricity rom bulk tank vehicles prior to commencing the delivery operation. In addition, storage containers greater than 2.5 kl water capacity should be electrically earthed as a protection against the accumulation o static electricity.

10.8.4

The placing o storage containers within 1.5 m measured horizontally rom the vertical plane o overhead electric transmission lines should be avoided.

Fig. 7 : A typical layout plan o LPG bulk storage acility

18

19








10.9

Maniolded cylinders location

(e)

a cylinder should be located at a distance o at least 5 m rom ammable or combustible liquid storage and other orms o combustible materials. This distance may be reduced

10.9.1

Cylinders should be located outside o buildings situated on a rm level ground in a well ventilated

to 3 m by using a deection wall o 2 hour re resistance rating.

location (Cylinders should not be installed in a basement or in locations below ground level – the (f)

gas is heavier than air and will “ow” into low points and collect causing a ammable or explosive mixture). The saety distance requirements or cylinders as stipulated by MS 830 are as ollows:

any exterior source o ignition, openings into direct-vent (sealed combustion system) appliances or mechanical ventilation air intakes should be at least 1.5 m in any direction away rom the nearest cylinder or opening to the compar tment whichever is nearer.

Table 4 : Cylinder location and saety distances

(g)

Aggregate water capacity o cylinders in a maniolded group o cylinders (kl)

meet the saety requirements and distances or outdoor installations.

From Fr om bui build ldin ing gA

From pro From prope perty rty boundary B

From a xed ignition source

None

None

Fixed ignition

Up to 2.5

(h)

7.5

7.5

the compartment should be separated rom the rest o the building by surrounding walls having 4 hour re resistance rating. The separation should be absolute in such manner that it will have no openings o access towards the inside o the building

source should not Over 2.5 to 10

a specially built compartment within the building boundary but meeting the ollowing requirements should be considered an outdoor installation and should be required to

Minimum saety distance (m)

proper.

all within Zone 0, 1 or 2 area (i)

10.9.2

According to MS 830 a cylinder installation outside a building should comply with the ollowing

(j)

requirements: (a)

the oor should be o smooth concrete and at least 100 mm higher than the ground. Rough surace that may cause sparking during cylinder handling should not be used.

Source : Table 10 o MS 830

electrical appliances installed in the compartment should be at least suitable or Zone 2[3] application and preerably located above the cylinder.

the water capacity o individual cylinder in a maniolded group o cylinders should

(k)

ventilation openings o at least 300 cm2 per 1 m2 o the oor area should be provided

not exceed 125 ℓ. I more than one maniolded group o cylinders are installed at a

and such opening should be as close to the oor as practicable, so as to prevent leaking

consumer site each maniolded group should be separated rom the border by at least

gas rom accumulating inside the compar tment.

7.5 m. A deection wall o 2 hour re resistance rating and a minimum height o 2 m may be used to reduce this distance to 3 m provided the vapour path should not be

(l)

less than 7.5 m. (See also Figure 9 in MS 830) (b)

a door o at least 1.5 m width should be provided with access orientated towards the outside o the building.

the installations should be enced and locked to prevent unauthorised access and

10.10

tampering.

Openings on storage container shell are provided with protective valves (to protect against inadvertent release o LPG) in accordance with MS 830 provisions. Accordingly, all openings on containers, except those or saety relie valves and those connections protected by an opening not larger than No. 54 drill size (0.0550

(c)

(d)

any opening into the building that is below the level o the relie valve should be at least

inch), should be equipped with excess ow valves or other suitable automatic valves or devices which will

1 m horizontally rom the nearest cylinder.

automatically prevent loss o the tank contents in the event o a connection or line ailure.

one or more cylinders may be installed below a window, provided that there is a minimum distance o 150 mm between the top o any cylinder valve and the bottom o the window opening

[3] speciallysel ected industrial, non-incendive orrestric ted breathing equipment

20

21








11 PIPE ISOLATION

12 GAS METERING

Isolation valves should be installed at strategic locations in the gas piping system to acilitate isolation o

12.1

sections or components o the piping system or servicing and maintenance and during emergency

A meter location agreed upon by the gas utility company should be provided as close as possible to the point where the gas service piping enters the building.

situations. Isolation valves must have manuacturer’s design and operating specications that are compatible 12.2

with the system operating parameters.

The location should be such that the meter, meter connections, gas service piping tee and gas service shut o valve are exposed and accessible or inspection, installation, replacement, removal, locking, unlocking

11.1

Isolation shut-o valve

and reading. 12.3

Isolation shut-o valve should be installed at branch lines, beore regulators and meters, at each riser point, at

11.2

Gas meters should not be located where meters will be subject to damage, such as in public passageways,

appliance points, to enable isolation o each sec tion o the pipe or maintenance) as well as during emergency.

over doors or in locations subject to dripping water or unusual moisture conditions or extreme high

Isolation valves should be o quick-action type such as manually operated ball valves.

temperatures or where the meter will be inaccessible. 12.4

Emergency shut-o valve (ESV)

Gas meters should be located at least 1 m rom sources o ignition. Meters should be securely supported and should be protected against overpressure, backpressure and vacuum.

This valve can be either manually or automatically triggered shut rom a remote location away rom the 12.5

valve unit. The valve is preerably o re-prooed type and should be installed at strategic locations such as

All riser/meter compartments should be naturally ventilated by xed louvers or pre-cast concrete ventilation

necessities beore entering a building, to enable remote shut-o during emergency. They may sometimes be

blocks at the top and bottom o the compartment to atmosphere. The door o the duct opening to the

controlled rom the building control room.

lobby area should be re-rated to the relevant authority’s requirement. 12.6

The service pipe termination and internal piping termination should be in line and parallel to the ace o the door o the riser shat or duct to enable the gas meter and control valve to be installed easily without the need or urther pipe adjustments.

12.7

Diaphragm gas meter installation should comply to MS1766:2004 (Installation o Diaphragm Gas Meters – Specication)

22

23








13 PIPE SIZING

13.1

14 PIPE INSTALL INSTALLATION ATION

Proper sizing o supply pipelines is important so that each gas appliance receives enough gas to perorm

14.1

General requirements

properly. Inadequate sizing o supply pipelines not only will cause inefcient appliance operation but also supply interruptions, which can adversely aect the saety o the system.

The general principles that must be borne in mind when planning a gas pipe installation on residential premises are as ollows:

13.2

Gas piping should be sized to provide the maximum demand, and such that the supply pressure at the gas (a)

utilization equipment is appropriate and greater than the minimum pressure required.

the piping system must be designed so that the gas meter provided by gas supplier can be properly located or or within the building o the owner or each customer.

13.3

Two dierent methods o pipe sizing are presented in Appendix C o the MS 930. These are; (b)

•

NFPA No 54

•

Cliord Method

gas pipes should be located such that the locations o isolation valves are easily accessible to the users to acilitate line isolation during emergency. Each oor or section o a building should be provided with an isolation point, in case o re or leakage at any o the sections.

13.4

The sizing tables in MS 930 contain gas-carrying capacities or dierent sizes and lengths o rigid pipe and (c)

semi-rigid tubing. The tables are in order by type o gas (natural gas or LPG), type o piping (pipe or tube), pressure, and pressure drop allowed.

gas pipes should, as ar as practicable, be run outside the building, especially when the operating line pressure exceeds 35 kPa (5.0 psi). However or maintenance purposes, it is recommended that pipe riser to be installed at accessible and reachable location near corridors or dedicated shats.

13.5

The design parameters must adhere to certain pressure limitations as stipulated in the applicable standards. (d)

For instance, under normal conditions, the maximum design operating pressure or piping located inside buildings should not exceed 35 kPa (5 psi) (as stipulated in MS 930 ) 13.6

gas pipes should preerably enter the building aboveground and remain aboveground and in ventilated location.

(e)

For larger and more complex gas piping systems that are not covered by MS 930, the size o the gas piping system should be determined by standard engineering methods acceptable to Energy Commission. These

gas pipes should be properly painted and labelled or identication identication purposes. The colour or gas pipes should be yellow.

are:

13.7

•

Pole’s Method

•

Cox’s Method

(f)

the pipe route selection should avoid any positions where the pipe could be liable to damage, either during the building construction or when the propert y is nally occupied.

The maximum allowable pressure drop recommended or the design o internal gas piping should be less

(g)

the re resistance o the building must not be impaired.

(h)

the route should, as ar as possible, avoid the need to cut into load-bearing walls or joist.

(i)

pipes may be concealed, but provision should be made or access. Exposed gas pipes would

than 15 percent. 13.8

The maximum gas velocity in the gas pipe should be less than 20 m/s such that the gas velocity should not have negative eects, or example, by eroding the pipe wall or creating nuisance to the public rom excessive noise emissions.

13.9

acilitate leak detection and maintenance. (j)

A recommended ormat or presenting gas reticulation network pipe sizing calculations is as shown below. (Pipe sizing sotwares are readily available rom Universiti Teknologi Malaysia.)

pipe riser ducts must have 2 hour re rated doors and have one side as an external wall with xed louvers or ventilated pre-cast block venting naturally to atmosphere.

Table 5 : Format or gas reticulation network pipe sizing calculations

Inlet Node

Outlet Node

Flow Rate scmh

Length m

CF

Diameter mm

Inlet Pressure kPa

Outlet Pressure kPa

Pressure Drop kPa

Pressure Drop %

Velocity m/s

24

25










(k)

there should be a space o at least 50 mm between a gas pipe and any other services. Where

(t)

each outlet, including pipe terminating with a valve, should be securely closed gas-tight with an

electrical services are being use in the same duct, the gas riser should be separated rom the

approved threaded plug or threaded cap immediately ater installation and should be let closed

electrical services by a gas-tight partition with respect to the electrical services.

until an appliance is connected.

(l)

pipes passing through a cavity must take the shortest route and be sleeved.

(m)

pipes are normally run above ceiling, dropping down to appliances on the oor below it, when no other route is available.

(n)

pipes must not be laid under or through oundations.

(o)

pipes should never run diagonally across walls or oor. They sho uld normally ollow the line o the walls and be kept close to them.

(p) (q)

the piping system must not be exposed to the excessive external stress, vibration or corrosion. the piping system must be installed at a location where maintenance and checking work can be done easily.

(r)

to prevent the distribution o gas leakage throughout the building, piping inside any building must not be installed at the ollowing locations: •

lit shat

•

ues, chimneys and gas vents Fig. 8 : A typical natural gas piping layout on domestic consumer’s consumer’s premises

•

circulating air duct and ventilating duct

•

clothes chute

•

enclosed staircase

•

in rooms provided with high voltage power acilities

•

air handling room

•

unventilated void space

areas through which the riser passes should be well ventilated. This will ensure early detection o

•

re protected/smoke ree/enclosed lit lobby areas

gas leaks, prevent accumulation o gasses to dangerous levels and allow access or maintenance.

•

within protected corridors or passageways which are routes o escape/exit

•

under load bearing oundations and walls

•

at area or location owned or exclusively used by third party (e.g. local authority)

the building should be provided to ensure that minor gas leakage does not cause the atmosphere

•

in case o riser not provided with ventilation, it is best to install gas detector to detect

within the duct to become unsae.

14.2

Pipe shat or duct 14.2.1

14.2.2

Where practicable, gas pipes within the building, including gas risers, should be r un exposed. The

Where a gas riser is to be located in a pipe shat (or duct), permanent ventilation to the outside o














14.2.3

Where shats are continuous, ventilation can normally be achieved by the provision o openings

14.3.2

Piping buried in a ground

at the top and bottom to the outdoors. Th e opening should have a minimum ree area (in inches square) equal to the product o one-hal o the maximum pressure in the piping (in psi) times

Underground pipes also need to be protected against aboveground loading by using protective

the largest nominal diameter o that piping (in inches), or the cross-sectional area o the duct,

sleeves and concrete slabs. When dissimilar metal are joined underground, an insulating coupling

whichever is smaller.

or tting should be used. Piping should not be laid in contact with cinders. Please reer to ourth schedule o Gas Supply Regulations 1997. 1997.

14.2.4

When a pipe shat takes the orm o an enclosure at each storey level, riser pipes should be re stopped as the pass rom one oor to another unless in their own protected shat which is ventilated top and bottom to outside atmosphere. When riser pipes rom a shat or duct enter a at or apartment unit they should b e re stopped at the point o entry.

Fig. 10 : Piping embedded in concrete oor

14.3.3

Pipe in oor channel The channels should be constructed such that the structural strength o the oor is not reduced and the pipes are wholly encased within the oor structure.

Uncoated threaded or socket welded joints should not be installed in contact with soil where internal or external crevice corrosion may occur. Piping which is in contact with soil or other materials, which may corrode the piping, should be protected against corrosion in an approved manner. Fig. 9 : Typical layout o ventilated gas pipe shat/duct

14.4

Pipe penetrating through solid wall or oor














Fig. 11 : Pipe penetrating through solid wall or oor

14.5

Underground pipe damage protection 14.5.1

Proper protective measures should be taken to protect underground gas piping against damage caused by the third party work. In addition, when underground gas piping is installed in sot soil, proper measures should be taken against dierential settlements.

14.5.2

Fig. 12 : Piping buried in ground oor or under concrete external o building

Underground gas piping installation beore the boundary line o private land should have a depth o cover not less than 900 mm. 14.6

14.5.3

Pipe Support

Underground gas piping installation beyond the boundary line o private land should have a depth o cover not less than 450 mm or deeper whichever is required by authority. The cover

14.6.1

The piping system must be supported to avoid the external stress such as vibration, thermal shrinkage and must be installed at a location where maintenance work can be done easily.

should be permitted to be reduced to a minimum o 300 mm i external damage to the pipe is

Gas piping should be supported with the proper size pipe hooks, metal pipe straps, bands or

not likely to result.

hangers. 14.5.4

Pipe casing or protection slab may be used where the depth o cover or underground gas piping is not sufcient to protect the pipe rom damage and should b e approved by authority.

14.6.2

The supports must be o adequate strength and quality, and located at proper intervals, so that the piping cannot be moved accidentally rom the installed position.

14.5.5

For steel underground gas piping installation, a cathodic protection will be used in conjunction with the coating to protect the gas pipe against corrosion.

14.6.3

The building structure should not be weakened by the installation o any gas piping. Gas piping should not be supported by other piping.

14.5.6

Warning marker (concrete marker) should be installed at suitable intervals along the straight and














Table 6 : Support o piping

Steel Pipe Nominal Size o Pipe mm (Inches)

Spacing o Supports m (Feet)

Nominal Size o Tubing mm (Inch OD)

Spacing o Supports m (Feet)

15 (1/2)

1.8 (6)

15 (1/2)

1.2 (4)

20 (3/4) or 25 (1)

2.4 (8)

16 (5/8) or 20 (3/4)

1.8 (6)

32 (1 1/4) or larger

3 (10)

22 (7/8) or 25 (1)

2.4 (8)

Ever y oor level

-

-

(horizontal) 32 (1 1/4) or larger

Fig. 13 : Underground gas piping

(vertical) 14.8.3

Source : Table 2 o MS 930

Clearance rom electrical cable without casing and lightning arrestor should be as per table below:

14.7

Pipe Tracer Wire Table 7 : Clearance rom buried electrical acilities

For polyethylene (PE) underground gas piping installation, a tracer wire is installed along the entire length o gas pipe or the purp ose o locating the gas pipe rom aboveground using a pipe locator. The tracer wire

Buried Facility

should be installed around the pipe surace and the wire ends should be led to aboveground, at every 50 m intervals, where the discontinuity can be detected easily. An insulated copper wire o at least 4 mm or AWG 14 should be used as tracer wire. 14.8

Clearance (mm)

Low voltage cable

> 100

High voltage cable

> 1000

Lightning arrestor

> 1500

Clearance rom Other Buried Facilities 14.9 14.8.1

by segregation or other means. Requirements or clearance (parallel and cross layout distances) rom other buried acilities is as shown in the gure below: 14.8.2

Drain Crossing

When a gas pipe runs close to some other services, contact between them should be prevented

For polyethylene pipe installation, ample clearance must be provided to separate such pipe rom any heat source in order to assure that the surace temperature o the pipe does not exceed 35o C

Drain crossing gas pipe should be installed under the drain as shown in the ollowing gure:














15 PIPE JOINTING

14.10

Connection o plastic piping (polyethylene piping)

15.1

Jointing methods must also be suitable or the particular gas reticulation design. Gas piping joints must have good strength and leak tightness properties. The joint must be able to sustain the maximum end orce due

When plastic piping (polyethylene pipe) is used as underground piping, connection between metallic pipe

to the internal pressure and any additional orces due to temperature expansion or contraction, atigue or to

(steel) and polyethylene pipe should be made only outside, underground and with approved transition

the weight o the pipe and its contents.

ttings. 15.2

Welded joints are normally used or their excellent strength and sealing properties under all operating conditions. However, sometimes sometimes threaded joints may be use or very small diameter pipes operating at low pressures. Threaded joints are very leak-prone, hence, they should not be used in concealed/underground pipe installations as stated in MS 930.

15.3

Although welding is preerred, threaded joints and ttings are permitted or pipe sizes up to and including 4” operating at 35 kPa (5 psig) or less. Pressure piping larger than 4” and all pressure piping above 35 kPa (5 psig) regardless o size must be welded or anged.

15.4

Joints in steel pipe may be welded in accordance with API 1104 1104 or ASME IX. Metallic pipe and t ting threads should be taper pipe threads and should comply with ANSI B2.1.

15.5

Joints in copper pipe should be br azed in accordance with ANSI/AWS B2.2-91. B2.2-91. Copper ttings should conorm to EN 1254.

Fig. 15 : Typical installation o anodeless riser tting

15.6 14.11

Isolation Joint Installation

Joints in polyethylene pipe should be made by heat usion in accordance with manuacturers’ instruction. Polyethylene ttings should conorm to ASTM D2683 or ASTM D3261. Plastic pipe or tubing should not be threaded.

Isolation joint should be installed in the ollowing location: 15.7 •

•

Welders o metallic gas piping or jointers o non-metallic piping must have a valid certicate o qualication

Location where pipes or ttings made o dierent materials are joined in buried portion.

rom the relevant authority such as DOSH or Construction Industry Board (CIDB). For this, welders have to

Transition portion between underground and aboveground piping, in case cathodic

pass perormance qualication tests according to the API 1104 or equivalent code requirements beore they

protection is installed, underground piping is protected with cathodic protection.

can be allowed to do the welding job.
















16 GAS APPLIANCE SELECTION

16.1

The gas appliance operating pressure range and required gas consumption rate must be able to be met by

17 GAS APPLIANCE INSTALLA INSTALLATION TION

17.1

the actual pressure and ow rate in the piping sys tem.

The gas appliance must be o the approved type and is suitable or the type o gas supply (natural gas or LPG) to which it will be connected. The installer should provide the user with all the relevant manuacturer’s instructions.

16.2

All appliances used must be type-approved by Energy Commission. Appliances designed or LPG must only be used with LPG and similarly, appliances designed or natural gas must be used only with n atural gas.

17.2

Gas appliances should not be installed in premises without the connection being tested or gas tightness, ascertaining that all the gas saety controls are in proper working order, ensuring that there is proper

In order to convert existing LPG appliances to operate on natural gas, the gas burner nozzles size must be 16.3

ventilation and the operating pressure is as recommended by the manuac turer.

changed or increased to the meet natural gas characteristics. Appliance conversions must only be perormed by competent persons registered with Energy Commission.

17.3

To enable appliances to be moved to a limited extent or convenience o use or to acilitate cleaning, a exible hose connection approved by Energy Commission should be used. The length o connecting hose or tube rom the gas cock to the appliance should not exceed 1.5 m. The material o the hose or tube should be rubber or copper approved by Energy Commission.

17.4

Adequate ventilation or combustion should be provided by ensuring air change, natural or otherwise in the kitchen as a whole. Separate ues or venting to the outside air are normally not required or domestic cooking appliances unless the kitchen area is ully air-conditioned. In such cases, ues should be designed and installed according to MS 930 requirements. Appliance manuacturers generally oer detailed inormation on proper venting o gas appliances. These instructions must be closely ollowed as specied in the appliance














18 INSPECTION, TESTING AND COMMISSIONING

18.1

Prior to acceptance and initial operation, all piping installations should be inspected and tested by a competent person to ensure that the materials, design, abrication and installation comply with the technical and saety requirements o the Gas Supply Regulations 1997 and recognized standards.

18.2

Inspection should consist o visual examination during or ater abrication, assembly or test as appropriate.

18.3

Corrosion protective coating should be subjected to holiday testing (test o the continuity o protective coating). Coating deects or damage that may impair eective corrosion control should be repaired prior to installation in the ditch as specied by the relevant codes such as MS 830 or National Association o Corrosion Engineers (NACE) Recommended Practice.

18.4

The pressure or leak test medium should be air, water or an inert gas (e.g. nitrogen, carbon dioxide). Gas may be used as the test medium at the maximum pressure available in the system at the time o the test.

Fig. 15 : Typical location o gas cock at cabinet cabinet type top range

18.5

Pipe joints including welds should be let exposed or examination during the test. Expansion joints should be provided with temporary restraints, i required or the additional thrust load under test.

17.6

Gas leak detector installation 18.6

Soapy water solution test may be used to locate leaks i all joints are accessible during the test. The test














19 OPERATION & MAINTENANCE

19.1

Table 9 : Natural gas piping system pressure / leak test requirements

Gas piping systems in service are subjected to various degrading or abnormal operating conditions such as third party activities, corrosive environment, ground erosion, excessive pressure uctuations, malunctioning

Maximum Scope

Type o Test

Test

Operating

Eq u ipm ent

Pressure

Pressure kPa(psi)

Test D ur a tio n (m (m in ut es)

Tes t

M ed ium

kPa (psi)

Above ground

Buried

Pressure gauge

Pressure

Soap

Chart

water

Recorder*

solution

or breakdown o components, material wear and tear, and tampering. It is the duty o the owner or occupier o the premises to saely operate and maintain the system in accordance with manuacturer’s specications. Gas detector**

19.2

From service station up to 2nd stage regulator /

the premises, or where there is no consumer or occupier, the owner o the premises or any person authorised Above 140 (20)

H yd r ost a ti c

Wa ter

H yd yd ro rost at ati c

Wa te ter

345 (50)

60

14 4 0

√

(√)

by the consumer or occupier to be in charge o the gas pipeline or gas installation in the premises.

√

meter

19.3

system. He is responsibilities as provided or under the regulations are as ollows:

/ area to 2 stage nd

His role is essentially to be in charge o the gas pipeline or gas installation in the premises to ensure that certain basic saety and administrative requirements are being adhered to in the operation and use o the

From service station up

The regulations provide or a ‘responsible person’ who may be the licensee or consumer, or an occupier o

Up to 140

Pneumatic/

(20)

leak

Nitrogen

345 (50)

12 0

14 4 0

√

√

√

Air

•

ensuring that the gas pipeline can be continuously identied,

•

immediately taking all reasonable steps to cause the supply o gas to be shut o in the event o him

regulator / meter

Leak(during

Natural

Operating

commisioning)

gas

Pressure

Pneumatik/

Nitrogen

√

√

(√)

knowing or suspecting gas escaping into the premises,














RECOMMENDED PREVENTIVE MAINTENANCE PROGRAMME FOR GAS PIPING SYSTEMS 19.4

Proper maintenance programmes and procedures including procedures or regular leakage surveillance o

Table 10: Natural gas and LPG piping

the system have to be prepared and ollowed by the responsible person. In addition to that, emergency

Maintenance Items

procedures have to be prepared and rehearsed or actual implementation during emergencies involving gas leakage or re. 1 19.5

using gas detector or soap liquid.

Frequency Every Two Years

The piping system must be subjected to a thorough inspection an d tested by registered competent competent persons at least once every three years. Pressure vessels must comply with DOSH requirements. Maintenance and repair works on the system must similarly be perormed by competent persons.

19.6

Detailed visual survey or pipe, connections, valves and equipments by

It is unlawul to remove or disconnect any gas equipment without rst plugging or capping with a screwed

2

Detailed visual inspection or pipe support and surrounding conditions around piping and gas appliances

Annually

3

Inspection or PE/Steel transition joints.

Annually

4

Inspection Inspection and unctional unctional test o valves and regulators. ators.

Annually ly

5

Air-tightness test or leak check testing.

6

Painting & labelling.

joint tting the outlet rom which the gas equipment was removed. All outlets to which gas equipment are not connected should be let capped gas tight on any piping system being installed, altered, extended or repaired.

Every Three Years

Ever y Two Years














RELATED STANDARDS STANDARDS AND CODES OF PR ACTICE FOR GAS PIPING SYSTEM Malaysian Standards (MS): MS 830:2003

Code o Practice or the storage, handling and transportation o liqueed petroleum gases.

MS 930:1986

Code o Practice or The Installation o Fuel Gas Piping Systems and Appliances.

MS 17 1766:2004 66:2004

Code o Practice or the Installa Installation tion o Gas Meters

MS 187 1870: 0: 2005

Gas meters (Diaphragm meters)

MS 1086:1987 1987

Specication or Buried Polyethylene ene (PE) Pipes or the supply o gaseous uels.

MS 153 1535 5

Part 1: 2002

Domestic gas cooking appliances or use with LPG: Specication.

Part 2: 2002

Domestic gas cooking appliances or use with LPG: General

MS 1165: 1989

Specication or pressure regulat regulators ors and automatic changeover devices or LPG

MS 831:1986

Specication or valves or use with domestic LPG cylinder.

MS 773:1999

Specication or exible rubber tubing and hose or use in LPG vapour phase and LPG/air installations

MS 217:1974

Method or the hydrostatic strength testing o liqueable and other compressed gas cylinders.

American Society o Mechanical Engineers (ASME) ASME B31.8:1999 1999

Code or Gas Transm Transmission ission and Distribution Piping Systems

American Petroleum Institute
















CONVERSION TABLE

SURUHANJAYA TENAGA HEADQUARTERS AND SURUHANJAYA REGIONAL OFFICES:

Conversion Table

HEADQUARTERS

Pejabat Kawasan Suruhanjaya Tenaga

Suruhanjaya Tenaga

Tingkat 10, Kompleks Teruntum














ACKNOWLEDGEMENT

We thank the following organisations organisations for their contribution, input and

NOTES














NOTES

NOTES













NOTES

Guidelines on Dometic Gas Piping System

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