This document provides an overview of city gas distribution systems. It discusses what city gas distribution is, the basic concepts of distribution systems including developing pipeline networks and maintaining different pressure levels. It outlines the key steps in designing distribution systems such as demand estimation, network design, and route surveys. The document also covers system components including city gate stations, pipelines, regulating stations, meters, and CNG stations. It concludes by discussing applicable codes, standards, and regulations for city gas distribution.

1. City Gas Distribution– An Overview

2. WHATIS CITY GAS DISTRIBUTION?
CGD is the last component of the Natural
Gas value chain delivering Natural Gas to
end users in town and cities to meet the
demand for a cleaner, more efficient,
economical and environmentally-friendly
energy source.

3. CITY GASDISTRIBUTION
CONCEPT
 Development of Pipeline Network in a pre-defined
geographical spread
 Maintaining Different Levels of Gas Pressure to meet
the Demand of various segments of gas users -
Domestic, Commercial, Industrial and Automobiles.
 Designing high pressure and medium pressure
network such that supply to any consumer is possible
from either side.
 Design gas storage / Gas sourcing for maximum
survival period
 Consider Health, Safety & Environment at all stages

4. Stepsinthedesignof GasDistributionSystem
• Market demand estimated based on comprehensive
field survey of units covering domestic, commercial,
industrial and transport sectors.
• Demand forecast projection is carried out for 20-25
years.
• Peak hour consumption estimated for network
design.
• The system is to be designed based on 20-25th year
projected demand at peak load in a phased manner.
• Reconnaissance Route Survey within the town to
identify suitable routes for laying pipelines, locations
for City Gate Station, District Regulating Station &
CNG Station

5. • Network design and optimization with available
software
• Design of Mother Station and Daughter / Daughter
booster station for CNG supply to automobiles
• National / International standards adopted for design.
• Project implementation done subsequently.
Stepsin thedesignof GasDistributionSystem

6. Battery Limits
Distribution Zone
Transmission Distribution
City Gate Station
TransmissionLine

7. HP Network
MPB Network
CITYGATE
Domesticand Commercial
Users
DRS DRSDRS
MPANetwork
CNG MotherStations
LP Network
CGD SYSTEMBASICCONCEPT

8. CGD PRESSURE REGIMES
Sr. No. Network Component Inlet from Inlet Pressure
Outlet
Pressure
Outlet to
1 CGS Transmission line 99 - 60 barg 26 barg Steel Grid
2 Steel pipeline CGS 26 barg 26 – 14 barg DRS / CNG
3 DRS Steel pipeline 26 – 14 barg 4 – 1 barg MP MDPE pipeline
4 Service Regulators (SR) MP MDPE Pipeline 4 – 1 Barg 110 mBarg LP MDPE Pipeline
5 MP MDPE pipeline DRS 4 barg 4 – 1 barg
Industrial MRS &
Commercial
Connections
6 LP MDPE Pipeline SR 110 mBarg 110 – 50 mBarg
Regulator of Domestic /
Commercial
Connections
7 Industrial MRS
MP MDPE pipeline
Steel pipeline
4 – 1.5 barg
26 – 14 barg
1.5 barg or
customer specific
pressure within
the supply range
Industrial internal
pipeline
8
Online / Mother CNG
Station
Steel Pipeline 26 - 14 barg 250 Barg Vehicle at 200 Barg
9 Domestic Connections LP MDPE Pipeline 110 – 50 mBarg 21 mBarg Meter & Gas Stove
10 Commercial Connections
LP MDPE Pipeline
MP MDPE Pipeline
110 – 75 mBarg
4 – 1 Barg
75 mBarg or
customer specific
pressure within
the supply range
Meter & Gas Stove

9. City Gas Distribution –
ApplicableCodes & Standards

10. European Standard
S. No. STANDARD NO. DESCRIPTION
1 EN 12186
Gas supply systems - Gas Pressure Regulating Stations for
Transmission and Distribution. Functional Requirements
2 EN 12279 Gas pressure regulating - installations on service lines
3 EN 1776
Gas supply systems - Natural gas measuring stations - Functional
requirements
4 EN 1594
Gas supply systems- Pipeline for maximum operating pressure over
16 bar- Functional requirements

11. AMERICAN SOCIETYOF
MECHANICALENGINEERS(ASME)
S. No. STANDARD NO. DESCRIPTION
1 ASME B16.11 Forged Steel Fittings, Socket-Welding and Threaded
2 ASME B31.3 Process Piping
3 ASME B31.8 Gas Transmission and Distribution Piping Systems
4 ASME B16.5 Pipe line flanges and flanged fittings
5 ASME B16.9 Factory - Made Wrought Steel Butt welding Fittings
6
ASME- Boiler and Pressure Vessel
Code
Section- IX- Qualification Standard for Welding and Brazing
Procedures, Welders, Brazers, and Welding and Brazing
Operators
7
ASME Boiler and Pressure Vessel
Code- II
Part C- Specifications for welding Rods, Electrodes, and Filler
Metals
8 ASME Boiler & Pressure Vessel Code Section - V, Non-destructive Examination
9
ASME Boiler and Pressure Vessel
Code
Section-II Materials Part A- Ferrous Material Specifications -

12. BS/DIN/ISOAND OTHER
STANDARDS
S. No. STANDARD NO. DESCRIPTION
1 ISO- 15590-1
International Standard for Petroleum and natural gas industries - Induction
bends, fittings and flanges for pipeline transportation systems
3 BS 6755: Part 2 Testing of Valves
4 DIN 30672, Part I
Coatings of corrosion protection tapes and heat-shrinking products for
pipelines for operational temperatures upto 50oC
6 DIN 30670 Polyethylene coatings for steel pipes and fittings

13. OIL INDUSTRYSAFETY
DIRECTORATE(OISDSTANDARDS)
S. No. STANDARD NO. DESCRIPTION
1 OISD-226 Natural Gas Transmission Pipelines & City Gas Distribution Networks
2 OISD-GDN-115 Guidelines on Fire Fighting, Equipment and Appliances in Petroleum Industry
3
Fire Protection Manual-
TAC
Fire Engines, Trailer Pumps and Hydrant Systems
4 OISD- Standard- 141 Design and Construction requirements for cross country hydrocarbon pipelines
5 OISD-Std-118 Layouts for Oil and Gas Installations

14. AMERICANPETROLEUM
INSTITUTE(API)
S. No. STANDARD NO. DESCRIPTION
1 API Standard 1104 Welding of Pipelines and Related Facilities
4 API Specification 5L Specification for Line pipe
5 API Spec. 6D
Specification for Pipeline Valves ( Gate, Plug, Ball and
Check Valves)
7 API Standard 1102 Specification for steel pipeline crossing & highways.

15. AMERICANGAS ASSOCIATION
(AGA)
S. No. STANDARD NO. DESCRIPTION
1 AGA Purging Principles and Practices
2 IGE/TD/1 Steel Pipelines for High Pressure Gas Transmission
5 AGA: Report No. 7 Measurement of Gas by Turbine Meters
6 AGA Report No.3 Orifice metering of Natural Gas and other related Hydrocarbon fluids
7 AGA-Report No 8
Compressibility factors of Natural Gas and other related Hydrocarbon
gases

16. City Gas Distribution –
System Components

17. CGD - InfrastructureMajor Constituents of CGD are;
 City Gate station
 Pipeline Network
 Steel Pipelines
 Poly Ethylene Pipelines
 GI / Cu Pipes
 Regulating Stations
 District RegulatingStations
 Service Regulators
 Domestic / Commercial/ Industrial Regulators
 Metering Stations / Metering & Regulating Stations
 CNG Stations

18. CITY GATESTATION(CGS)
CGS is the location of Custody Transfer from
Transmission Company to Distribution Company.

19. CITY GATESTATION(CGS)
➢Inlet & Outlet isolation valves
➢Knock Out Drum (KOD),If required
➢Filter
➢Metering Unit (Turbine / Orifice / Ultrasonic)
➢Gas Chromatograph (GC), If required
➢Pre-heater (if required)
➢Pressure reduction skid comprising
➢Active & monitor Regulators
➢Stream discrimination arrangement
➢Slam shut valve for over & under pressure protection
➢Creep relief valves.
➢Odorising Unit

20. STEELPIPELINE
 The Steel Grid pipeline sizes is 12”NB & 8”NB whereas, spur
lines shall be of 6”NB & 4”NB.
 Steel pipelines used in the distribution system is fully
coated. The coating is extruded polyethylene, with each
weld joint coated with either heat shrink sleeves or field
applied tape.
 Prior to the pipeline being put into service, the distribution
pipeline to be non-destructively tested by two methods.
Firstly, welds would be radio graphed and, secondly, the
completed pipeline extension would be hydro-statically
tested at a higher pressure than its operating pressure.
 After hydrostatic testing, the pipeline to be dried, purged
and filled with natural gas. The testing and commissioning
procedures will be detailed during the detailed design phase
of the project.

21. STEELPIPELINE
 To protect the pipeline from corrosion, a cathodic
protection (CP) system of impressed current is
proposed. During the detailed design phase, the CP
capability of the existing transmission system will
be investigated to establish if it has the capacity to
provide CP to the extension. If it is found that the
existing system does not have the capacity,
additional CP facilities will be designed.
 The steel grid is installed at a minimum depth of 1.0
meter cover, and in accordance with Indian
requirements.

22. MDPE PIPELINE
 The distribution pipe is with Standard Dimension
Ratio (SDR 9) for 20 mm, (SDR) 11 from 32 mm up
to 63 mm & (SDR) 17.6 for above 63 mm. The term
SDR is defined as the normal outside diameter (DN)
divided by the minimum wall thickness.
 It is standard practice in India to have a minimum
1.0 meter cover. This additional depth in a densely
populated area would be recommended.
 All MDPE pipe back filled with sand around it to
protect the plastic material.

23. MDPE PIPELINE

24. Medium Density PolyEthylene (MDPE)
Pipes
➢Tech Spec: IS 14885:2001& ISO 4437
➢Material Grade & Color: Internationally approved resins of PE 100 grade of
Orange color
➢Minimum Required Strength (MRS) of PE 100 grade pipe: 10 MPa
➢Pressure Class: SDR 9 (dia 20 mm), SDR 11 (dia 32 & 63 mm)and SDR 17.6 (dia
90, 110, 125 and 160 mm).
➢Operating pressure: 4 bar (g).
➢Operating temperature range: - 10 0 C to + 40 0 C.

25. Advantages of PE pipes
➢High performance (Globally proven leak free system)
➢More Flexibility, coil ability, ductility, High elasticity
➢Low density (low weight, high strength to weight ratio)
➢High resistance to corrosion
➢Low heat conductivity (small thermal loss)
➢Smooth surfaces (low pressure losses due to low pipe friction)
➢Easy to transport, handle and lay
➢Longer life

26. Advantages of PE pipes
➢Easier and speedier joining techniques to ensure leak tight joints by
employing electro fusion techniques
➢Higher productivity, i.e., reduction in installation time (15 minutes
in case of PE against 4 hours in case of steel), thereby lesser
inconvenience to public
➢Reduced number of joints, hence safer and leak free system
➢Less time is consumed to repair PE damages as compared to steel
damages
➢Good squeeze off properties

27. Advantages of PE pipes
➢Longer design life of PE pipes (50 years) as compared to steel
pipeline (30 years)
➢Avoidance of NDT techniques in building premises, which is very
critical
➢Size of trench is less in case of laying of PE pipe as compared to
steel

28. MDPE Fittings
➢Tech Spec: ISO 8085-3 or EN 1555-3
➢Material Grade: PE 100
➢Terminal pin size: 4 or 4.7 mm
➢Voltage: 39 – 40 Volts.
➢Color: Black.

29. PE Stop Off Valves (Typical)
➢Standard: ASME B 16.40, EN 1555-4
➢Pressure Class: SDR 11.
➢Design Pressure: 5.5 bar (g).
➢Design Temperature: 45 0 C.
➢Operating Temperature: 10 0 C to 45 0 C
➢End Connections: PE Material (Spigot Type)
➢Stem Extension: Integral stem extension required
(Minimum 690 mm from the Top of Pipe)
➢Valve Design: One piece construction.
➢Ball position Indicator: Open / Close limits required.

30. Crimping Fitting (Typical specification)
➢Used to connect u/g PE pipes with a/g GI pipes
➢Operating Pressure:up to 4 bar (g)
➢Operating Temperature: 40 0 C
➢Hydrostatic Test Pressure: Minimum hold Pressure of 10 bar (g),
for 1 hour duration
➢Pneumatic Test Pressure: Minimum pressure of 6 bar (g), for 1
hour duration
➢Pull out Test:
• Shall not fracture within the jointedassembly
• Shall withstandthe Pneumatic pressure leak test
• Shall not leak

31. District Regulating Stations

32. District Regulating Station

33. District Regulating Station

34. Service Regulators

35. Typical requirements of Pressure Regulators
used for domestic and small I&C customers
➢Maximum Inlet Pressure: Maximum 4 bar (g)
➢Nominal Outlet Pressure: 100 mbar (g)
➢Flow capacities: 50, 150, 200, 250 scmh
➢End connections: Threaded (& Tapered) as per BS 21
➢Operating ambient temperature: up to 45 0C
➢Lockup: Maximum pressure, under no-flow condition, up to 125 mbar (g)
➢Creep relief valve: To protect against downstream over pressure at low flows or
in the event of valve seat malfunction, preset to 140 mbar (g)
➢Over Pressure Shut Off (OPSO): Device to protect againstdownstream over
pressure, preset to 160 mbar (g)
➢Under Pressure Shut Off (UPSO): Device to protect against downstream under
pressure with a pressure setting range 40 mbar (g) to 65 mbar (g)

36. Regulator Selection
Information required to select a regulator:
➢ Maximum and Minimum inlet pressure
➢ Required outlet pressure
➢ Maximum flow rate
➢ Tolerance on outlet pressure
➢ Size of pipework
➢ Type of gas
➢ Safety features required
➢ Size of orifice
➢ OPSS, UPSS & Relief settings
➢ Installation indoors of outdoors
➢ Orientation of regulator

38. Gas Meters
The most common types of meters used are:
➢Diaphragm
➢Rotary Positive Displacement (RPD)
➢Turbine

39. Diaphragm Gas Meters (Domestic)
➢Tech Spec: EN 1359
➢Capacity: 2.5 m3/hr
➢Rangeability or TD ratio: 1:150 or better
➢Nominal Working Pressure:21 mbar (g)
➢End Connections: ¾”, as per BS 746 (Male)
➢Center to Center distance: 110 mm between
inlet and outlet connections

40. Diaphragm Gas Meters (Commercial)
➢Tech Spec: EN 1359
➢Capacity: 10, 25, 40, 65 scmh
➢Rangeability or Turn Down ratio (ratio
of Qmax and Qmin): 1:150 or better
➢Nominal working Pressure: 100 mbar
(g)
➢Pressure rating : Suitable to withstand
maximum working pressure of 200
mbar (g)

41. Rotary Positive Displacement (RPD) meters
▪ Tech Spec: EN 12480
▪ Volumetric meter
▪ Appropriate for medium size load
▪ TypicalTurndown35:1 to 50:1
▪ Accuracy ±1%
▪ Large measuring range
▪ Not sensitive against disturbances
▪ Not sensitive against fast changes in
flow rate
▪ Needs lubrication

42. Rotary Positive Displacement (RPD) meters

43. Advantages Disadvantages
Good flow turndown Filtration essential (50 microns or
finer)
Tolerance to installation effects
and load behaviour
Requires lubrication
Accuracy ±1% Physical size at large capacities
Much smaller than a diaphragm
meter
Can create pressure fluctuations
on on/off loads
Very long life Can cut off gas supply when it fails
Expensive
Rotary Positive Displacement (RPD) meters

44. Industrial Metering Station (IMS)
➢IMS are used to measure gas supplied to Industrial consumers
➢Main component in IMS is filter, Isolation Valves, RPD Meters with EVC &
Modem, Regulators (If low pressure requirement) and Non return Valve
➢Inlet pressure range – 1.5 Barg to 4 Barg
➢Outlet pressure – As required by customer

45. MRS components
➢Inlet & Outlet isolation valves
➢Filter
➢Pressure regulator with a built in
slam – shut device
➢Relief valve
➢Strainer
➢Flow Meter (RPD, Turbine, etc.)

46. GI ERW Pipes
➢Tech Spec: IS 1239 (Part 1)
➢Types used: Medium Class and Heavy Class
➢Material: IS 1387
➢Pipes shall be screwed with Taper threads
➢Threads: Tapered and conforming to BS 21
➢Galvanizing: IS 4736
• Coating requirements: Mass of coating is 400 gms / m2
➢Test Pressure: 5 MPa
➢Powder Coating:
• Powder Material: Pure Polyester
• Application: Electrostatic spraying (40 – 90 KV, Manual /
Automatic)

47. GI Fittings (Malleable Cast Iron)
➢Tech Spec: IS 1879
➢Material: IS 2108 Grade BM 290
➢Dimensions: IS 1879
➢Threads: IS 554
• All Internal & External Threads shall be tapered
• Chamfer shall have included angle of 900 +/- 50 for
Internal threads & 700 +/- 100 for external threads
➢Galvanizing: IS 4759
• Coating requirements: Mass of coating is 700 gms /
m2.

48. Forged Fittings (Wrought Steel
Iron)
➢Tech Spec: IS 1239 Part 2
➢Material: IS 1387
➢Dimensions & Tolerances: IS 1239 Part 2
➢Threads: IS 554
• All Internal & External Threads shall be tapered
• Chamfer shall have included angle of 900 +/- 50 for Internal threads
& 700 +/- 100 for external threads
➢Galvanizing: IS 4759
• Coating requirements: Mass of coating is 700 gms / m2.

49. Brass Valves
(Meter Control Valves, Riser Isolation Valves &
Appliance Valves)
➢Tech Spec: EN 331
➢Pipe Nominal Diameter :- ¼” to 2” NB.
➢Operating Pressure: 4 bar (g).
➢Operating Temperature: 10 – 60 0 C.
➢Material: Nickel Plated Forged Brass.
➢Pattern: Full Bore, Quarter Turn Ball Valve.
➢Handle: Suitable Metallic Handle, Lever / Knob /
Cap Type with yellow coating (Powder / Plastic) on
Surface marked as “GAS”
➢End connection: Screwed, As per BS EN 10226-1,
Tapered Threaded, Female

50. Meter Regulator
➢Gas flow rate: 2.5 m3/h
➢Nominal Inlet Pressure: 100 mbar (g)
➢Maximum Inlet Pressure: 160 mbar (g)
➢Nominal Outlet pressure: 21 mbar (g)
➢Lock-up pressure: Shall not exceed 30 mbar (g)
➢Low pressure Cut-Off: at inlet pressure of 11.5 mbar to 15 mbar (g).
• Re-pressurizationsafety device is fitted which prevents the regulator from re-
opening when the inlet pressure is restored unless there is a downstream
backpressure, i.e., all connected appliances have been turned off.
➢End connections: Right angled inlet and outlet connections of ¾”x ¾” BSPT
(Female)

51. Rubber Hose (flexible and steel
wire braided)
➢ Used to connect the appliance, inside the
house of domestic customer
➢ Tech Spec: Type IV of IS 9573
➢ Size: 8 mm NB
➢ Material: It consists of
A. Lining: Synthetic rubber like Nitrile
Butadiene Rubber (NBR) or Chloroprene
Rubber (CR)
B. Reinforcement: Wire reinforced in
braided form in between the lining and
the cover
C. Cover: Consolidated by wrapping, and
uniformly vulcanized to give good
adhesion

52. Rubber Hose (flexible and steel
wire braided)
➢Mechanical Properties:
• Tensile strength: Minimum 10 MPa for lining and cover
• Elongation at break: Minimum 200%for lining and 250% for cover
➢Salient features:
• Strong (Steel wire reinforced) hence rats can't bite through steel wire Flame
resistant
• Abrasion, ozone and weather resistant, hence no cracks
• Low temperature flexibility
• Minimum burst pressure of 0.5 MPa
• Long life (5 years)
• Grip strength (to nozzle of appliance)

53. City Gas Distribution– Network
Design

54. SystemBasics
 System of units
 The International System of Units (SI), also known as the "Metric System"
to be used. The International Gas Union (IGU) has also recommended to
generalize the use of the SI system in all matters relating to Gas and Gas
facilities. The SI system shall be in compliance with ISO 1 000. The SI
system shall be of general use with exception to the following:
 Gas Volumes and Flow,
 Pressure,
 Temperature,
 Heating Value
 Pipeline and Piping Nominal Diameters shall be expressed under
either one or both systems where "Common Practice" of Pipeline and
Piping Engineers so suggests;

55. SystemBasics
Data relating to equipment shall use that system of unit that is most
common in the relations with suppliers.
Where advisable for good understanding, the corresponding value in
the other System of Units shall be mentioned between brackets.
Results of technical calculation and related figures issued from specific
software shall remain expressed in that system of units that is used by
the relevant software.

56. Steel Pipelines
Steel mains
◦ Notwithstanding the major advantages of polyethylene (PE), steel pipelines
remain necessary as follows;
High-Pressure Mains
◦ Location class: the design of High pressure mains shall consider
requirements as for Location Class 4 (ASME 31.8) to allow timelessness
should the environmentchange in the future.
◦ Wall thickness: according to ASME B31.8 – Section 841.11 with Design factor
of 0.4. In addition, wall thickness shall, in no way, be lower than the values
below in function of NominalDiameter (ND)

57. Steel Pipelines
 4 in. and below - 3.9 mm
 6 in. - 4.5 mm
 8 in. - 5.0 mm
 10 in. - 5.6 mm
 20 in. - 6.3 mm
GSPC Gas is using 6.4 MM Wall thickness.
 Steel Grade: The Design Concept considers API Grade X 52 Steel
quality to offer maximum flexibility for line pipes procurement.
 Bend Radius: to allow pigging under special circumstances

58. Steel PipelinesSteel Pipes
◦ API 5 L - Line Pipes
◦ ASTM A 106 - Seamless Pipes
◦ ASTM A 333 - Seamless & Welded Pipes for low temperature services
Location Class
◦ LocationClass I - 10 or fewer buildingsin 1 mile section
◦ LocationClass I I - 10 – 46 buildingsin 1 mile section
◦ LocationClass III - 46 or more buildingsin 1 mile section
◦ LocationClass IV - Areas where multi story building & heavy traffic plus
other underground utilities
Steel Pipe Design Formulae
P = (2 St/D) * FET – As per ASME B 31.8, 841.11 (a)
t = PD / 20fs

59. Steel PipelinesAbove Ground Mains
◦ Polyethylene being forbidden for above ground crossings, if any, steel mains
sections are needed at the crossing with PE/steel transition fitting to be buried
with the adjacentPE mains.

60. Steel PipelinesProcess Design
◦ Wey-mouth Formulae
◦ Q = 0.0813 * (d)2.6667 * {(p12-p22)1/2 / (S * L)1/2 }
Velocity
◦ V = Q / A
◦ Velocity for filtered gas to be 40 m/s & unfiltered
gas to be 20 m/s maximum.

61. Example
P 1 = 15 Barg, P2 = 10 Barg (Min.)
◦ Q = 2,00,000 SCMD
◦ L = 32,000 m
1 2

62. Example
Q = 2,00,000 SCMD i.e. 9,166.66 SCMH
Using Wey Mouth Formulae: Q = 0.0813 * (d)2.6667 * {(p12-p22)1/2 / (S * L)1/2}
◦ 9166.66 = 0.0816 x (d)2.6667 * {(16.0132-10.0132)1/2/(S* L)1/2}
◦ d = 198.52 mm : CalculatedDiameter.
◦ We have to select diameter from the availablerange e.g. 200.1 mm from API 5
L
Now, P1V1 = P2V2
◦ 1.013 * 9,166.66 = (9.32+1.013) * V2
◦ V2 = 898.8 M3 / Hr = 0.2497 M3 / Sec.
Now, for Velocity, Q = A * v
◦ 0.2497 = (3.14/4) * (200.1 * 10-3)2 * v
◦ V = 7.94 m/s
Now, for Wall Thickness, t = (P*D) / 20fs
◦ t= (16.013 * 219.1) / (20 * 0.29 * 241)
◦ t = 2.5099 mm

63. Example
P 1 = 26 Barg, P2 = 10 Barg (Min.)
◦ Q = 1 Q = 9250
◦ L = 12000 m L = 20000
◦ Q = 4000
◦ L = 7000
1 2 3
21

64. PolyethylenePipelinesMRS (MinimumRequired Strength)
◦ The MRS value represents the long-term circumferential stress in the
pipe under which the break may occur after 50 years at the earliest.
◦ Stress = MRS / C, where C is overall service coefficient
◦ The minimum value of C for the material to be used for Gas application
is 2.
MAOP (Max. allowable Operating Pressure)
◦ MAOP = (20 * MRS) / [C * (SDR-1)].
Standard DimensionRatio
◦ SDR = Dn / En
◦ SDR used in GSPC Gas is SDR 9, SDR 11 & SDR 17.6
Standard followedby GSPC Gas
◦ IS 14885:2001

65. PolyethylenePipelinesBase resin
◦ The PE resins of “Third Generation” (PE 100 or MRS 10) in full compliance with
detailed specification is being used. First Generation is PE 63, second PE 80 &
Third generationis PE 100.
Wall thickness
◦ The MDPE network designed and qualifiedfor a MOP of 4 bar.
◦ The “Network analysis” and resulting structure and behaviors are based on
such design. PE line pipes wall thickness shall be in accordance with the
following SDR
◦ Gas mains (ND ≥ 90 mm): SDR 17.6
◦ Gas mains and Servicelines (ND ≤ 90 mm): SDR 11.
◦ Service lines (ND = 20 mm): SDR9

66. PolyethylenePipelines
 Different Material used for PE Pipes
 The following materials have been approved to date:
 Solvay Eltex TUB 121(Black) or Eltex TUB 125(Orange) PE 100
 Borealis HE 2490 PE 100
 Fina Finathene XS 10 B PE 100
 Dow BG 10050 PE 100
 Elenac Hostalen CRP 100 PE 100
 Codes:
 Manufacturer Commercial Brand Name Code(*)
 SOLVAY ELTEX TUB 121/125 E3
 BOREALIS HE 2490 N3
 FINA FINATHENE XS 10 B F3
 DOW BG 10050 D3
 ELENAC HOSTALEN CRP 100 H7

67. PolyethylenePipelinesProcess Design
◦ Wey-mouth Formulae
◦ Q = 0.11672 * (d)2.664 * {(p12-p22)0.544 / (S * L)1/2}
◦ Velocity
◦ V = Q / A
◦ Velocity for filtered gas to be 40 m/s & unfiltered
gas to be 20 m/s.
◦ Being a complex network, required specialized tools
for Planning & Designing the network. GSPC Gas use
SynerGEE software for designing the PE Network.

68. PNG Domestic& Commercial
ConnectionProcess Design
◦ Polyflow Formulae
◦ Q = 1.522786 * 10-3 * (d)2.623 * {(h/L)0.541}
◦ Peak Gas flow is assumed @ 0.5 SCMH for one house
◦ Being a standard PNG Connection, we have
standardize the design of PNG Network as follows;
◦ ½” GI pipes up to G + 4 apartments OR 5 connections in case of raw house.
◦ 1” GI Pipe above 5th
Floor apartment OR abovefive connections in raw house.

70. PNG Domestic& Commercial
ConnectionRoute Selection for GI / Copper Pipe Installation
 Route selection for GI pipe installation shall be carried out as per the
guideline given below;
 Pipe shall not be installed on un-plastered wall or in the house under
construction.
 Pipe shall not be installed in an unventilatedvoidspace.
 Route shall be selected that maximum length of the pipeline shall be installed
outside.
 Route of the pipelineshall be plannedfor the shortest possible length.
 The gas pipeline shall be away (minimum distance of 200mm) from the
electrical line.
 There shall be minimum change of directions and minimum no of threaded
joints.
 Maximum two Point in the kitchen for gas stove only.
 Compound gate or doors and windows inside the house shall not hit the Gas
pipeline.
 Copper installation should be a minimum 300mm away from heat source and
Electrical installations. If it is not possible for copper installation then suitable
protection should be given.
 If the copper pipe installation is carried out inside cupboards, there should be
a provisionfor adequate ventilationlike louvers/holesin cupboard doors.

71. PNG Domestic& Commercial
ConnectionPositioning of Valves, Regulator & Meter
Riser IsolationValve:
◦ For apartments, one riser isolation valve shall be provided at a height of 2
meter
◦ From the ground and individual meter control valve shall be installed for each
connection.
◦ The riser isolation valve shall be installed at a convenient height so that it is
easy to operatethe valvein emergency.
Meter Regulator:
◦ Regulator shall be installed in such a way that it reduces the length of H.P. Line
(Max. pressure 0.1 Bar) to minimum possible.
◦ Wherever possible meter Regulator shall always be installed outside residence
and at a convenientheight.

72. PNG Domestic& Commercial
Connection Gas Meter:
 Gas Meter shall be installed in such a way that it shall be protected from
direct rain or waterfall on the meter. Location of the Gas meter shall be
decided during the route selection.
 Meter shall be installed at convenient height so that it is easy for the
meter reader to take correct readings.
 The meter shall never be positioned very near to Electric Line. A
minimum distance of 200 mm shall be maintained.
 Appliance Valve:
 The position of the appliance valve shall be convenient to operate and it
shall keep the rubber tube at a safe distance from the heat source.
 The orientation and distance from cooking platform/ground shall be
maintained in such a way that the Bending Radius of the Rubber Tube
shall be more than 100mm.
 Appliance valve shall be installed in ventilated space and the lever of
appliance valve shall not foul with the wall during the on-off operation.

73. Clamping

74. GI Pipecutting & Threading
 After site and route clearance, the measurements for pipe cutting shall be
taken and pipes shall be cut accuratelyas per the required lengths.
 If the length of pipes is not correct, the threaded joints come under heavy
stresses, which may ultimatelycause gas leakage.
 Installed piping threaded connections / joints shall be tightened in such a way
that all the joints shall be free from heavy stresses and misalignments due to
incorrect pipe length.
 The condition of thread die and pipe vice jaws shall be checked regularly and
shall be free from defects.
 Cutting fluids (oils) shall be used while thread cutting.
 Threaded pipes shall be handled carefully so that the threaded oily portion
shall be free from dust, mud, water and any damage due to impact of any
object.
 Cutting burrs on the pipe shall be removed from the edges. The edges shall
be straight and free from Knife-edge formation.

75. G.I. PipeInstallation&
Clamping Teflon tapes shall be wrapped on threaded portion of the pipe with
minimum three overlaps. The Teflon tap should be of approved make and
gauge.
 The no of clamps shall be adequate. The pipeline portion containing the
Regulator and Meter, either horizontal or vertical, shall have clamps on both
side of the regulator and meter. Clamps shall be fitted in such a way that
they do not create misalignment of pipes.
 The clamp shall be installed by drilling 6 mm hole in plastered wall and
screwed using rowel plug.
 Distance between two clamps shall not be more than 2 meter; the gap
between riser and wall shall be minimum 25 mm.
 Clamps shall be installed in a straight line and shall be parallel to each other.
 The clamps shall be fixed properly on the walls and should grip pipe in
position.
 For wall crossing, drill the hole with the help of electrical drilling machine in
such a way that plaster and tiles shall not be damaged. It shall be ensured
that there is no concealed wiring or any other fitting on the opposite side of
the wall for a particular location of drilling.

76. G.I. PipeInstallation&
Clamping Self-adhesive anticorrosive tape shall be wrapped on the pipe with 50%
overlap.
 Casing sleeve shall be installed in wall for wall crossing.
 Alignment of the pipeline shall be maintained.
 Whenever compound gate, house door or window hits the G.I. pipe
protection clamp shall be installed to protect the pipe.
 Concealed piping shall not be done.
 All the pipes shall run on walls with clamps. Pipe should not be overhung
and shall not be installed without pipe clamp.
 Wherever powder coating is peeled off during fitting and tightening of the
pipe, touch up shall be done after the installation is completed by two coats
of approved paint.
 Prior to installation all pipes and fittings shall be checked internally to
ensure that they are free from any obstruction.
 PE to GI (transition fitting) joint shall be provided above ground.

77. Installationof Valves,Regulator &
Meter
 Union and testing T shall be installed before riser isolation valve.
 Meter control valves, Meter regulator and Gas meter shall be protected
from the over tightening of the thread.
 Valves, Meter regulator and Gas meter shall be installed with the clamps
on both sides. As far as possible hex nipple shall not be used for
connecting. Both side threaded 3” to 8” long pipe nipple shall be used.
 Gas meter, regulator and installed piping shall be aligned properly.
 Flow direction of the gas meter shall be checked before installation.
 Flat rubber washer shall be checked and ensure at inlet and out let of
the adaptor joint to the meter.
 Pipe nipple shall be installed between elbow and regulator to avoid
direct load of line or riser on regulator and a clamp must be provided on
the pipe nipple.

78. Testing of InstalledPiping
Connection
 Before carrying out the pneumatic test of the whole installation; testing
assembly, air foot pump with pressure gauge / manometer shall be
checked its calibration and proper functioning.
 Before pneumatic testing of the installed connection spacing between
two clamps, tightening of the clamps thread joints, alignments of the
whole piping shall be checked. Valve shall be kept in open position and
the appliance valve shall be kept in close position.
 Calibrated pressure gauge shall be used having the range of 0 – 1 Bar.
 Position of the pointer of the pressure gauge shall not be marked with the
marker pen on the glass. It should be recorded in the test records.
Pneumatic testing pressure shall be kept 1.5 times of the working
pressure and should be maintained for 30 minutes.
 After pressurization of the whole piping section shall be checked for the
leakage with the help of soap solution.
 During the testing, air should reach up to the appliance valve. After
completion of testing, pressurized air shall be released from appliance
valve only.

79. Conversionof BurnerAll the appliance valve and riser isolation valve shall be kept in closed position.
Ensure thatmeter and regulator adaptor shall be leak proof.
Open the burner knob and remove the plug from the hot plate.
Clean the simmer hole.
Make the simmer hole of 0.6mm with the help of simmer drill.
At the time of drilling the hole, ensure that it should not be inclined.
Remove the dust from plug.
After greasing, plug and knob should be properly positioned at their original position.
Remove the burner from hot plate and clean it.
Open the existing jet (LPG) and replace it by 125 no jet if it is big burner or 110 no jet if
it is small burner.
Place the burner on its original position and connect the nozzle with appliance valve
using flexible and braided rubber hose.
The length of rubber hose shall not exceed 1.5 mtr.
Both the ends of the rubber hose shall be clamped by metallic clamps on the nozzle.
Check all the joints with soap solution and ensure that the flame color should be blue.

80. All the Best