Our Product - LPG GAS PIPE LINE

TECHNICAL SPECIFICATION FOR LPG GAS PIPE LINE

1.1 Cylinder Bank (manifold, click-on adaptor, cylinder pigtail, non-return valve)

A cylinder bank consists of two sets of manifold. On each manifold the required number of cylinders which can meet the total gas demand of the Colony are connected. As stated earlier a bank consists of 2 batteries or sets of cylinders( or 2 manifolds), one in active mode and the other reserve. A manifold is basically a seamless pipe of 1” diameter. Its length is determined by the number of cylinders which are connected to it (about 10”/per cylinder). Threaded nipples are welded on the manifold. Each point of connection of the cylinder to the manifold has got a click-on adaptor, a cylinder pigtail and a non-return valve. An adaptor is like a pressure regulator which is fitted directly onto the cylinder. However, unlike the regulator, the adapter does not reduce the pressure. When adaptor is turned on, gas starts flowing out of the cylinder at unreduced pressure thus coming out of the cylinder at full cylinder pressure. A cylinder pigtail is a flexible wire-braided rubber tube which has a brass nut on both ends. Its one end is screwed on the adaptor and the other end on the non-return valve. When a pigtail is damaged it can be easily replaced by unscrewing the old one & screwing in the new one. A non-return valve, whose one end is screwed on the cylinder pigtail and whose second end is screwed on the threaded manifold nipple, shuts off the gas supply coming out of an individual cylinder to the manifold in case the cylinder pigtail of that cylinder bursts. The non-return valve also shuts off supply if there is a fault in the adaptor or the connection is loose. Thus, there is no interruption in the gas supply system & all other cylinders continue to supply the gas except the cylinder which has a defective adaptor or pigtail. In the meantime, the defective pigtail/adaptor is replaced. When we open the adaptor on each cylinder, gas starts flowing from each cylinder to the common manifold & thus manifold gets a huge supply of gas which is sufficient to meet the demand of entire Colony.

1.2 Pressure gauge, manifold isolation valve

A pressure gauge is installed in each manifold which measures the pressure in the manifold before the first stage regulator. This pressure is same as the full cylinder pressure. After the pressure gauge an isolation valve is installed on each manifold. If you shut off this valve, the entire supply of gas from that manifold is stopped.

1.3 Automatic changeover valve cum regulator

The system has got an Auto Changeover Device (Valve & Regulator) which is interconnected to both the cylinder manifolds (one Main & one Reserve). This is also called first stage regulator and it reduces the pressure from 50-70 psig to 10 psig. The same automatically changes over from the empty Bank to the full bank once the LPG gets exhausted in the active bank. Thus flat owners get uninterrupted LPG supply 24 hours a day, 365 days a year.

1.4 Over pressure shut off valve

To take care of excess pressure build-up in the pipeline after the first stage regulator, an Over Pressure Shut Off (OPSO) system coupled with the Regulator, is provided. The same closes the flow of LPG into all the households, once the pressure exceeds the settings of OPSO device. This is also called Slam Shut Off Valve. A similar system is provided on the second stage regulator which is fitted in the kitchen of each flat.

1.5 Fire extinguishers

Fire extinguishers and sand buckets are kept near the cylinder bank system to meet any fire hazards near the manifold as per the statutory requirements.

1.6 Main pipeline isolation valve and pressure gauge

This valve is installed at the start of the main pipeline after the overpressure shut off valve (OPSO). If you shut off this valve then the gas supply to the entire colony is stopped. Before this valve, a pressure gauge is installed which indicates the pressure of gas in the main pipeline immediately after the first stage regulator.

1.7 Pipeline and its branche

This is a long steel pipeline which runs throughout the colony right from the cylinder bank to each individual flat of the colony. It has many branches whose diameters and lengths depend on the number & location of flats. Although it is preferable to lay open pipeline, one has often to lay concealed or underground pipeline due to architectural or structural design considerations. When a pipeline is laid deep in the earth (3 feet deep) across a road, it is covered with a concrete hume pipe of larger diameter so that no big load of traveling vehicles comes on it directly. The pipes used in the system are ERW welded pipes conforming to heavy duty class of IS: 1239. In the case of multistoreyed apartments, it is a common practice to lay a vertical branch pipeline to feed the flats whose kitchens lie vertically one above the other. Such a pipeline is called Riser Pipeline. An isolation valve is installed near the ground level of each riser pipeline. If you shut off this valve, the gas supply to that set of vertical flats is stopped. Similar arrangement is done on a branch pipeline which feeds a few flats together & these flats may not lie vertically one above the other. This is done to take care of any emergency arising out of any leakage in that section of pipeline which is feeding a cluster of flats. From the riser pipeline or the horizontal branch pipeline, a tapping is taken which goes to each individual kitchen.

1.8 Set up inside the kitchen

Near the entrance of each kitchen (and sometimes outside the flat) an isolation valve is fitted. If you turn off this valve, gas supply to that flat is stopped. After the isolation valve (item 13) a second stage regulator with under-pressure shut off valve (UPSO) is fitted into each kitchen which reduces the pipeline pressure from about 10 psig to about 0.5 psig. This is the normal pressure at which cooking is done in households. The UPSO closes the flow of LPG into the kitchen, once the pressure falls below the settings of UPSO device due to any reason such as failure of the regulator or low pipeline pressure etc. Hence UPSO will close the flow of gas if there is a drop of pressure (below the settings) either at the inlet or at the outlet of 2nd stage pressure regulator. After the second stage regulator a gas meter is installed inside each kitchen which measures the quantity of gas consumed by each flat. Each flat owner

gets a monthly bill as per the gas meter reading just like electricity meter. After the gas meter and before the gas appliance a quarter turn ball valve is fitted which the housewife uses to close or open the gas supply to that appliance. The quarter turn valve is connected to the rubber tubing whose second end is connected to hotplate or any other cooking appliance. You can use many gas appliances such as hotplate, gas oven, gas lantern etc. Each appliance will have a quarter turn valve which can be individually switched on or off. These quarter turn valves are in addition to the switch on/off knobs which are a part of the individual appliances. One can also install an LPG water heater in the bathroom.

or an LPG air heater in the drawing room by extending the pipeline. This can be done at the time of first installation or even later on.

2. TECHNICAL SPECIFICATION OF CRITICAL COMPONENTS

At present there are no technical specifications issued by Bureau of Indian Standards on components like click-on adaptors, flexible wire-braided cylinder pigtails, non-return valve, cylinder manifold, isolation valves, first stage pressure regulators, second stage pressure regulators, gas meters, quarter turn valves - used in commercial and industrial LPG installations. However, we are indicating below technical requirements of the components used in consultation with Oil Industry and foreign specifications. The pipeline contractor should furnish manufacturer’s test certificate of the components supplied

2.1.1 Function of adaptor-

An adaptor is like a pressure regulator which is fitted directly onto the cylinder. However, unlike the regulator, the adapter does not reduce the pressure. Its one end is connected to the cylinder & second end to the cylinder pigtail. When adaptor is turned on, gas starts flowing out of the cylinder at unreduced pressure thus coming out of the cylinder at full cylinder pressure. Thus normal gas pressure in an adaptor is from 3.5 kgf/cm2 to 5 kgf/cm2 (50 to 70 psig).

2.1.2 Specification of adaptor

Body of adaptor is pressure die-cast from zinc alloy. Brass parts used shall be made from free cutting brass bar. The rubber components such as O-rings(minimum 2 O-rings) shall be made from nitrile rubber and should satisfy the technical requirements of rubber specified in IS: 9798. The inlet of the adaptor shall have parallel left-hand male threads conforming to Systems International threads with a thread angle of 60 degrees & a pitch of 1.814 mm. (see Fig 5 of IS:8737). The outlet of the adaptor shall have left hand male taper threads conforming to MECV(Male European Cylinder Valve) so that it matches with the internal threads of the cylinder pigtail.The adaptor shall be marked with the manufacturer’s brand name & the words “unreduced pressure”.

2.1.3 Testing of adaptor

The body of adaptor shall be tested for a hydraulic pressure of 25.4 kgf/cm2 (360 psig). After machining, the adaptor shall be tested at a pneumatic pressure of 0.5 kgf/cm2 as well as at 17 kgf/cm2 to check leakage at both low & high pressure. The minimum gas flow rate should be 7 kg/hr at 7 kgf/cm2.The adaptor should work satisfactorily in the temperature range of -20 deg + 65 deg centigrade when tested in accordance with Annexure F of IS:9798. 4.1.4 Brand of adaptor used – SKN/Vanaz.

2.2 FLEXIBLE WIRE-BRAIDED CYLINDER PIGTAIL

2.2.1 Function

A cylinder pigtail is a flexible wire-braided rubber tube which has a brass nut on both ends. Its one end is screwed on the adaptor and the other end on the non-return valve. The gas passes through the cylinder at full cylinder pressure. The normal pressure is between 50 to 70 psig. When a pigtail is damaged it can be easily replaced by unscrewing the old one & screwing in the new one.

2.2.2 Specification

The rubber used in the tube shall synthetic & acryl nitrate butadiene rubber and resistant to LPG. The brass nuts used shall be preferably forged from wrought or extruded sections. Alternatively it could be made from free cutting brass. The nuts shall have left hand female threads conforming to FECV (Female European Cylinder Valve) and shall match the outlet threads of click on adaptor. The nut shall be machined as per Fig 6 of IS: 8737:1995

2.2.3 Testing

The raw tube shall be tested hydraulically at a pressure of 42 kgf/cm2 (600 psig). The finished pigtail shall be pneumatically tested at a pressure of 17 kgf/cm2 (240 psig). The burst pressure shall not be less than 33.8 kgf/cm2 (480 psig). The tubing shall be so flexible that it will make contact with a cylindrical former of radius at least 40 mm for at least 1100 of its circumference when tubing is placed over a former and a mass of 2 kg is attached at both ends. The tube shall be subjected to a crushing force of 102 kgf/cm2(1450 psig) on the middle of the tube over a length of 25 mm for 5 minutes. After the removal of force and lapse of 30 minutes, the tube shall not show any deformation or collapse, nor shall leak when subjected to an internal pressure of 17 kgf/cm2(240 psig).

2.2.4 Type tests

In addition the following type tests shall be conducted: The rubber material shall not show a weight change of greater than 5% and a volume change of greater than 10% after immersion in pentane for 72 hours. The hardness on the flat surface of the slit/cut tubing shall be 60 IRHD with a tolerance of 5. The accelerated ageing test on rubber shall be conducted in accordance with clause 4.3 of IS: 3400 (Part 4)The rubber material shall not show a deterioration of its hardness by more than 10 IRHD. The change in elongation shall be within + 25% and – 25%. The change in tensile strength shall be within + 10% and – 30%. The material shall withstand a clamping pressure of 5 kgf/cm2 wherby it shall not press away, flow away or be bruised or damaged. .2.4 Brand used –Markwell/United.

2.3 NON-RETURN VALVE, NRV

2.3.1 Function

A non-return valve, whose one end is screwed on the cylinder pigtail and whose second end is screwed on the threaded manifold nipple, shuts off the gas supply coming out of an individual cylinder to the manifold in case the cylinder pigtail of that cylinder bursts. The non-return valve also shuts off supply if there is a fault in the adaptor or the connection is loose. It does not allow the LPG to flow back from the manifold to the burst pigtail. Thus, there is no interruption in the gas supply system & all other cylinders continue to supply the gas except the cylinder which has a defective adaptor or pigtail. In the meantime, the defective pigtail/adaptor is replaced. The normal pressure in NRV is between 50 to 70 psig.

2.3.2 Specification

The non-return valve size is designated as FECVxMECV. The FECV end is fitted on the steel nipple of cylinder manifold & the MECV end is fitted on the cylinder pigtail.

2.3.3 Testing

The non return valve is tested at a pneumatic pressure of 17 kgf/cm2 for its functional operation. Brand used – SKN/United.

2.4 CYLINDER MANIFOLD

2.4.1 Function of manifold

The manifold is a running storage place where the gas withdrawn from a number of cylinders is fed into and it continuously gets a huge supply of running gas which is continuously withdrawn by a whole set of consumers via an elaborate piping system. It has two arms one in the “Active” mode and the other “Reserve”. The manifolds are designated by the number of cylinders connected at a time. For example, a manifold size of 2x50 indicates that it consists of two sets of cylinders, both sets being suitable for connecting 50 cylinders at a time. The normal pressure in the manifold is betwwen 50 to 70 psig.

2.4.2 Specification

A manifold consists of a seamless pipe of nominal bore of 1’’ conforming to ASTM A-106. It is fabricated from a single length of a tube & has no joints in the running length. MS nipples equaling the number of cylinders used are welded on the seamless tube at regular intervals. The interval is 14” for cylinders up to 19 kg for standard manifold and 8” for staggered manifold. The respective values are 17” and 9” for 50 kg cylinders. The nipple end fits into the non return valve end of FECV & hence its size is MECV. The manifold is painted red. One end of the manifold is blanked by welding forged or extruded mild steel blanking plate. The distance between the blanked end of the arm and the centre line of the nearest drilled hole(for fitting the steel nipple) shall be 3”( 76 mm) & the corresponding distance at the non-blanked end shall be 6”( 150 mm)including the manifold isolation valve. The manifold should be factory-made & duly tested there. Fabrication of manifolds at site is strictly prohibited.

2.4.3 Testing

The manifold will be pressure tested hydraulically at a pressure of 25.4 kgf/cm2(360 psig) for 30 minutes. All nipples and holes shall be suitably plugged before commencement of the test. Any reduction in pressure during the test period or leakage or sweating during the test period shall be treated as failure of the test. Also a similar pneumatic test at 10 kgf/cm2(142 psig) shall be done for 5 minutes.
Brand used: United/Greentech

2.5 PRESSURE GAUGE IN MANIFOLD

2.5.1 Function

To indicate the gas pressure in the manifold. The normal pressure is between 50 to 70 psig

2.5.2 Specification

The pressure gauge used at the manifold (Before the PRS 1) shall have a 4” dial, & shall be suitable for pressure range 0 to 10 kgf/cm2

2.5.3 Testing

The pressure gauge shall be tested against a calibrated gauge in the pressure range specified. Brand used –Alott

2.6 ISOLATION VALVE FITTED ON PRESSURE GAUGE

2.6.1 Function

It can stop or open the gas flow to the pressure gauge. Normally, the isolation valve is open. If a pressure gauge becomes defective, the isolation valve is closed & the defective pressure gauge removed & replaced by the new one. The normal pressure is between 50 to 70 psig

2.6.2 Specification

The brass valve body is either forged or made from free cutting brass. The minimum tensile strength of the material of valve body shall be 40 kgf/mm2 & minimum elongation 18%. The minimum izod impact strength as per IS: 1598 shall be 2.2 kgf.m. The valve shall work satisfactorily in the temperature range of –200C and +650C

2.6.3 Testing

The valve is tested pneumatically at a pressure of 17 kgf/cm2(240 psig) as well as at a low pressure of 0.5 kgf/cm2 ( 7 psig) Brand used – Zhiquing/LEO

2.7. MANIFOLD ISOLATION BALL VALVE

2.7.1 Function

After the pressure gauge an isolation ball valve is installed on each manifold. If you shut off this valve, the entire supply of gas from that manifold is stopped. The manifold isolation valve is subjected to full cylinder pressure which is normally between 50 to 70 psig

2.7.2 Specification

The size is 25 NB (ie 1” nominal bore).The valve is made from carbon steel and have PTFE seats and gland washers. The lever and spindle have a dual lock system for 900 turn (quarter turn) operation. The valve is hydraulically pressure tested at a pressure of 25.4 kgf/cm2. The rubber and other moulded parts shall be suitable for extreme climatic conditions, the range of temperature being –200C and +650C

2.7.3 Testing

The valve shall be pressure-tested hydraulically at a pressure of 25.4 kgf/cm2 and pneumatically at a pressure of 17 kgf/cm2 Brand used –Audco/L & T

2.8 AUTOMATIC CHANGEOVER VALVE C UM ADJUSTABLE REGULATOR

2.8.1 Function

Auto Changeover Valve cum Regulator is interconnected to both the cylinder manifolds (one Main & one Reserve). This is also called first stage regulator and it reduces the pressure from the cylinder pressure of 50-70 psig to 10 psig. The same automatically changes over from the empty bank to the full bank once the LPG gets exhausted in the active bank. Thus flat owners get uninterrupted LPG supply 24 hours a day, 365 days a year

2.8.2 Specification

The outlet pressure is adjustable between 0.5 kgf/cm2 to 1 kgf/cm2 (7 psig to 14 psig). The flow rate is between 20 to 50 kg/hr depending on the number of cylinders in the manifold. The body & cover is made from die cast zinc alloy. Diaphragm & valve pad from synthetic nitrile rubber. It is suitable in the temperature range of –100 C & +650C. It should conform generally to IS:9798 with suitable changes in the pressure which is more in this case than the domestic regulators covered in IS:9798

2.8.3 Testing

The applicable tests shall be done as per IS:9798 and IS: 4786, after making due corrections of operating pressure. Brand used – Vanaz/United

2.9 FIRST STAGE OVER PRESSURE SHT OFF VALVE, OPS

2.9.1 Function

To take care of excess pressure build-up in the pipeline after the first stage regulator, an Over Pressure Shut Off (OPSO) system coupled with the regulator, is provided. The same closes the flow of LPG into all the households, once the pressure exceeds the settings of OPSO device. This is also called Slam Shut Off Valve. A similar system is provided on the second stage regulator which is fitted in the kitchen of each flat

2.9.2 Specification

The shut off pressure shall be 1.5 kgf/cm2 (21 psig).The capacity shall be between 20 to 50 kg/hr

2.9.3 Testing

The OPSO shall be tested for the inlet pressure range of 2 kgf/cm2 to 17 kgf/cm2 Brand used – Vanaz /United

2.10 PRESSURE GAUGE ON MAINLINE

This item is similar to items 2.5 except that the pressure range is between 0 to 5 kgf/cm2. Brand used is Alott

2.11 ISOLATION VALVE FITTED ON PRESSURE GAUGE ON MAINLINE

This item is same as item no. 2.6 except for the size. The brand used is Zhiquing,LEO

2.12 MAINLINE BALL ISOLATION VALVE

This item is same as item 2.6 except that its size is 40 NB( 1½”)& inlet pressure is 0.5 to 1 kgf/cm2. Both the inlet and outlet of valve have BSP female threads of size 1½” which are screwed on the male threads on pipe. Brand used is Zhiquing,LEO

2.13 ISOLATION BALL VALVES AT RISERS

This item is exactly same as item no. 7. The size is also same ie 15 NB( 1/2”). Brand used is Zhiquing,LEO

2.14 ISOLATION BALL VALVE INSIDE EACH KITCHE

2.14.1 Function

2.14.1 Function

Near the entrance of each kitchen (and sometimes outside the flat) an isolation valve is fitted. If you turn off this valve, gas supply to that flat is stopped.
This item is similar to item 12 except that the size is 15 NB nominal bore( ½”). Both the inlet and outlet have ½” BSP female threads which are screwed on to the male threads on pipeline. The brand used is Zhiquing,LEO

2.15 Second Stage Pressure Regulator with UPSO (Item No. 15)

2.15.1 Function

After the isolation valve (item 14) a second stage regulator with under-pressure shut off valve (UPSO) is fitted into each kitchen which reduces the pipeline pressure from about 10 psig to about 0.5 psig. This is the normal pressure at which cooking is done in households. The UPSO closes the flow of LPG into the kitchen, once the pressure falls below the settings of UPSO device due to any reason such as failure of the regulator or low pipeline pressure etc. Hence UPSO will close the flow of gas if there is a drop of pressure (below the settings) either at the inlet or at the outlet of 2nd stage pressure regulator.

2.15.2 Specification

The inlet pressure range is 0.5 to 1 kgf/cm2 ( 7 psig to 14 psig) and the outlet pressure range is 0.020 to 0.030 kgf/cm2(=28 mb=0.3 psig to 0.45 psig). The flow rate is 0.5 Nm3/hr (=18 cft/hr= 1 kg/hr). Technical requirements are more or less same as in IS:9798 Low pressure regulators for use with liquefied petroleum gas (LPG) mixtures.

2.15.3 Testing – as per IS: 9798

2.15.4 Brand used – VANAZ/UNITED

2.16. Gas Meter

2.16.2 Specification

After the second stage regulator a gas meter is installed inside each kitchen which measures the quantity of gas consumed by each flat. Each flat owner gets a monthly bill as per the gas meter reading just like electricity meter

2.16.1 Function

It should conform to BS 4161 Part 5. The maximum working pressure(Pmax) ie outlet pressure is 0.1 kgf/cm2(=1.4 psig=100 mb). The normal working pressure range is 0.020 to 0.050 kgf/cm2 (0.3 psig to 0.7 psig). The max gas flow rate is 2.5 Nm3/hr(=88 cft/hr= 5 kg/hr) and the minimum rate is 0.016 Nm3/hr(=0.5 cft/hr=0.03 kg/hr). It is designated as G1.6 meter.

2.16.3 Testing -The meter shall be tested for conformity to flow rate

2.16.4 Brand used: RAYHEM RPG/ITRO

2.17 Quarter Turn Ball Valve (Item No.17)

2.17.1 Function

After the gas meter and before the gas appliance a quarter turn ball valve is fitted which the housewife uses to close or open the gas supply to that appliance. The quarter turn valve is connected to the rubber tubing whose second end is connected to hotplate or any other cooking appliance. One can use many gas appliances such as hotplate, gas oven, gas lantern etc. Each appliance will have a quarter turn valve which can be individually switched on or off. These quarter turn valves are in addition to the switch on/off knobs which are a part of the individual appliances

2.17.2 Specification and testing

It is same as item no. 14 except that its outlet does not have threads but a brass nipple on which the rubber tubing is slipped on.

2.17.3 Brand used – Zhiquing,LEO

2.18 Steel Pipes of varying diameters

2.18.1 Function

A series of pipes of different diameters & having various branches including risers(vertical pipes) carry the gas from the manifold system to the kitchen of each flat.

2.18.2 Specification

All the pipes used in the system are ERW welded pipes conforming to heavy duty class (Class C)of IS: 1239(part 1):1990 Mild steel tubes, tubulars and other wrought fittings. Part 1 Mild Steel Tubes. The dimensions are given in Table 3 of this specification. The testing is also as per IS:1239 (Part 1)

It is to be noted that Nominal Bore(NB) represents neither the outside nor the inside diameter of pipe. It is merely a reference denoting the approximate bore of the pipe. For each size of pipe, the outside diameter is fixed by the corresponding screw thread dimensions of IS: 554;1985(=ISO 7-1), and therefore the actual bore of each size of tube will vary according to thickness. Three classes of pipes are there depending on thickness. These are light(=class A), medium (=class B) and heavy (=class C). All screwed pipes are supplied with pipe threads conforming to IS:554:1985. The threads in IS:554 are taper male threads or parallel female threads. The basic form of taper threads is taper of 1 in 16 measured on diameter. The angle between the flanks, measured in an axial plane section is 550. The parallel threads also have an angle of 550

The sizes in accordance with IS:1239 (Part 1) used are as follows


• 40 NB nominal bore pipe ( 1½” ) Item No. 18

This runs from outlet of the First Stage Regulator(Item No. 8) to the verical risers. The max ouside dia is 48.8 mm and minimum 47.9 mm. The thickness is 4.0 mm. The permitted tolerance on thickness is –10% with no limit on plus tolerance.

• 25 NB pipe (1”) Item No. 19

This runs from start of risers to upto isolation valve in kitchen ie Item No. 14. The maximum OD is 34.2 mm and minimum 33.3 mm. The thickness is 4.0 mm. The permitted tolerance on thickness is –10% with no limit on plus tolerance

• NB pipe (½”) Item No. 20

This runs in the kitchen. The max OD is 21.8 mm and minimum 21.0 mm. The thickness is 3.2 mm. The permitted tolerance on thickness is –10% with no limit on plus tolerance

3. CODE OF PRACTICE FOR LAYING AND PRESSURE TESTING OF PIPELINE

3.1 Laying of Pipeline

The pipeline shall be laid as per IS:6044 (Part 1): 2004 – Code of Practice for liquefied petroleum gas storage installations (Part 1) Commercial and Industrial Cylinder Installations.

3.1.1 When a pipeline is laid deep in the earth (3 feet deep) across a road, it is covered with a concrete hume pipe of larger diameter so that no big load of traveling vehicles comes on it directly

3.1.2 Two coats of red oxide will be applied on piping above ground.

3.1.3 Suitable insulation tape or coating will be applied on the surface of that portion of pipeline which is laid underground so as to prevent its corrosion due to soil conditions

3.1.4 Suitable electric welding machine will be used such as single phase or 3 phase transformer type. The welding will be done by an experienced welder. The electrodes used will be Advani Oerlikon brand

3.2 Pressure testing of pipeline

3.2.1 Manifold 25 kg/cm2 hydraulically for 1 hour. The normal gas pressure in this section is about 7 kgf/cm2. The maximum attainable pressure in this section at 65 deg centigrade is 16.87 kgf/cm2

3.2.2 Piping after 1st stage regulator & before 2nd stage regulator - Pneumatically for 30 minutes at 2 kgf/cm2. The normal gas pressure in this section is about 0.7 kgf/cm2(10 psig).
Note: The test duration will be 30 minutes for each 500 cubic feet (or 14.159 cubic meter ie 14,159 litres of pipe volume(based on inner dia of pipe) or fraction thereof.

3.2.3 Kitchen piping beyond the gas meter - Pneumatically at 150 gf/cm2 ( 2 psig) for 10 minutes. The normal gas pressure in this section is 0.030 kgf/cm2 (=30 gf/cm2 = 28 mb= 0.4 psig). Hence, the test pressure here is 5 times the working pressure. The regulator and gas meter shall not be a part of this pressure testing.

Note: The test pressure of 1 kgf/cm2 specified by BPCL in its document is very high & needs to be modified. By testing at 150 gf/cm2, we are also eliminating the possibility of connecting inadvertently the 2nd stage regulator & gas meter in the pressure testing process & subject them also to a high test pressure of 1 kgf/cm2. This will damage both the gas meter & the regulator. Many inexperienced workers of contractors who took instructions from equally ignorant officers of gas supply agencies have caused damages to gas meter and PRS-2. Subjecting a low pressure pipeline (of 0.028 kg/cm2) to a high pressure of 1 kg/cm2 pressure is dangerous. Even IS:6044 (part 1) mentions a test pressure of 150 gf/cm2

4.CIVIL CONSTRUCTION WORK

Digging of trenches – The width of the trench shall be commensurate with the pipe diameter. The depth will be 3 ft where there is a road crossing and 2 ft otherwise.

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