Presentation on OISD-STD-220

8/7/2019 Presentation on OISD-STD-220

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Lays down min safety requirements for PNG distribution in cityand town.

It covers equipments, pipelines, accessories installedbetween up-stream inlet isolation valve of CGS and Consumer meter for commercial and industrial consumers

First isolations valve downstream of consumer meter for domestic

consumer

It is necessary to comply with statutory regulations such as State Pollution

Board, Factories Act, Indian Explosives Act, Municipal Authorities etc as

applicable and requisite approvals shall be obtained from the relevant

competent authorities for the PNG distribution system.


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(CGS & PRI) Min distance of 6 mtrs from other installation

Min distance of 2 mtrs from building structure

Min 2 safety device and 1 OPSO for installation whereOP is greater than 4 bar

Min 3 gas leak detectors at the strategic locations in the

CGS to cover entire facility

Vent Line min height of 3 mtrs above the equipment for above

ground installations and 3 mtrs above the ground level

for under ground installations

ISOLATION OF CGS Quick acting isolation valves shall be provided at CGS

for emergency isolation purpose.


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STEEL PIPING All the pipes and fittings need to confirming to ASME B 31.8 or

equivalent. CI pipe not allowed for PNG.

piping shall be designed for max operating pressure of 19.0barg. at temperature ranging between (-) 30 Deg. C to (+)55 Deg. C.

The above ground mains shall be painted yellow foridentification

POLY ETHYLENE (PE) PIPING

The PE piping, tubing, fitting and other components shallconform to requirement of ASME B 31.8 or equivalent asapproved by statutory authority. The PE piping shall bedesigned for maximum operating pressure of 4.0 barg. Attemperature ranging between (-) 20 Deg. C to (+) 55 Deg. C.PE piping shall not be used for major water/ rail crossing.


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STRATEGIC VALVES 3 KM for steel pipelines.

1KM for PE Pipelines of dia more than 63 mm

For PE Pipelines less than 63 mm dia, the distancebetween strategic valves shall be based upon risk

analysis Such valves shall also be provided on each riser,

upstream of each meter and at both ends of river &

railway crossing


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The isolation valve down stream of consumer meter

shall be easily accessible

Meters duly certified by competent authority shall beused

The pressure regulator shall be capable of shutting

down the downstream gas supply in case of low orhigh pressure in the system

The pressure ranges for different consumers shall be as

under:

a) Domestic Consumer : 21- 30 mbarb) Commercial Consumer : 21- 100 mbar

c) Industrial Consumer : 21 500 mbar


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The PNG pipeline route should avoid;

Areas congested with other underground utilities likepower, water, telephone etc

Close proximity to unstable structures or where constructioncould lead to damage to pipeline

Close proximity to highly populated buildings such asschools, public places etc

Ground areas of running sand, gravel or flood risk, waterbodies

Areas of known or suspected aggressive soil conditions

Landfill sites

Steel Pipe should avoidx Close proximity to existing CP systems, particularly groundbed

locations

x High stray direct current, typically near DC traction systems

x Long runs parallel to high voltage overhead conductors


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shall be placed on the entire pipeline at a distance not

exceeding 50 meter and also at bends in the city

Additional sign/ markers shall be installed to indicate thepresence of a pipeline at road, highway, railroad, streamcrossings and locations where there is a probability ofdamage or interference

A marker shall be marked in easily readable locallanguage with at least the following :

Name of PNG distribution company Contact telephone number(s) in emergency

Location code

Warning- High Pressure Gas Line and Other Utilities to takepermission from PNG distribution company before digging etc.


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The pipeline laying shall conform to the provisions asspecified in ASME B 31.8 or equivalent as approved bystatutory authorities. In addition, safety provisions

under OISD-GDN-192 (Safety Practices DuringConstruction) shall be complied

Following shall also be complied;

Road signs, warning lamps and barrier systems shall beprovided on highway or other work locations whichare accessed by pedestrians or vehicles

Electricity cables shall be treated as "Live, unless theowner certifies them as "Dead

Min distance of 250 mm shall be maintained from anyother utility

Warning mate to be used in open cut, difference in

elevation of pipe and warning mate shall be 200 mm


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As built drawing and pipe book shall be maintained

Trench width min 300 mm, pipe bed shall be free from

sharp objects, padding of soft soil / sand of min 100

mm below pipe

Min cover shall be as below

Location Min. Cover

in meter

Industrial, Commercial Residential Areas 1. 0

Stream, Canal and other minor water crossings 1. 5

Drainage ditches at roadways and railroads 1.0

Rocky Areas 1. 0Road Crossings 1. 2

Railroad Crossings 1. 7

Inside the building premises 1. 0


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TESTING OF INSTALLATIONS

HYDROSTATIC TESTING Steel pipe shall be tested at 1.5 times of max OP

Duration of the test shall not be less than 24 hrs.

Design Pr.(bar)

StrengthTest Pr.(bar)

DurationHydro.(H)/Pneu. (P)

Up to 0.1 0.3 P (5 Min.)

From 0.1 to 1.0 2.0 P (5 Min.)

From 1.0 to 2.0 3.0 P P (5 Min.)

From 2.0 to 7.01.5 DP

P or H

(30 Min.)

From 7.0 to 100.0 H (30 Min.)


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PNEUMATIC TESTING

Pneumatic testing of PE PIPELINE complywith the following:x For services with OP less than 75 mbar, air /

inert gas at min 100 mbar

x For services with OP in excess of 75 mbar, testpressure shall be 1.5 times of OP

x Pipelines operated above 2 bar, test pressureshall be 1.5 times of OP max

x Risers and laterals shall be tested at 350 mbar

Min duration of the test shall not be less than10 min.


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All fire protection and detection facilities

shall be in place before commissioning

All facilites i.e. CGS, PRI, Pipelines etc.

shall be purged and commissioned as per

approved procedure after due checks andcertification by the authorized personnel


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Presentation on OISD-STD-220

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