International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021

Layout Planning, Execution, and Testing of City Gas

Distribution (CGD) Network of Pipelined Natural
Gas (PNG)
Pranav Randive, Aniket Rasal, Jishan Shaikh, Rahul Thakare
1. Student, Department of Mechanical engineering, MVPS’s KBT College of Engineering, Nashik
randivepranav@kbtcoe.org
2. Student, Department of Mechanical engineering, MVPS’s KBT College of Engineering, Nashik
rasalaniket@kbtcoe.org
3. Student, Department of Mechanical engineering, MVPS’s KBT College of Engineering, Nashik
shaikhjishan@kbtcoe.org
4. Professor, Department of Mechanical engineering, MVPS’s KBT College of Engineering, Nashik
thakare.rahul@kbtcoe.org

1. Abstract
PNG (Pipelined Natural gas) pipeline for city gas distribution network is a promising future for Indian cities. The Methane gas
which flows through these pipes is the main contributer of natural gas in this network. This paper discusses the procedure and
steps in the planning and execution for the natural gas network . In this paper, we have computerized the flow of the natural gas
into a network of PE and GI pipeline provided into the phase - 1 of its laying i.e., for MCV – 1. CFD analysis for the methane
gas has been the main focus of this paper in our project of laying the network of PE and GI pipeline through the given apartment.
After Simulation the results are analyzed based on the pressure drop through the network for proper flow of the gas

I. Introduction consist of dimensions of the pipe, material roughness, various

As information provided by COP of MNGL (Maharashtra joints and fitting to be used, environmental conditions, space
Natural Gas Limited), Natural gas mainly contains of Methane constraints etc.
which occurs naturally as a mixture while extraction. This • Achieving less pressure drop and velocities across the
Natural Gas is provided in Nashik City with the help of MNGL laid network into the provided area of the society.
as a distributer which is the Joint venture of Gail India and • Development of Pipeline Network in a pre-defined
BPCL. As Natural Gas is 40 percent Lighter than air and has geographical spread
high ignition temperature above 1000 degree C it becomes • Maintaining Different Levels of Gas Pressure to meet
much safer to use than LPG which is regularly used in the the Demand of various segments of gas users
Indian households. The mixture of natural gas contains (Ethane, • Designing a high pressure and medium pressure
Methane and Propane) it becomes vital to understand the flow network such that supply to any consumer is possible
and pressure of the gas throughout the pipeline. This study from either side.
focusses on the pressure drop of the methane gas neglecting the • Consider Health, Safety & Environment at all stages
outer conditions or any other effects.
CFD is known as Computational fluid dynamic, it is a modern II. Objectives
software related to the fluid mechanics numerical analysis and To achieve optimal pressure and flow rate at consumer end and
algorithms to solve and analyze problems that involve fluid to avoid leakages at fittings. Also, to utilize minimum no. of
flows. Computers are used to perform the calculations required fittings for minimal losses.
to simulate the interaction of liquids and gases with surfaces
defined by boundary conditions.[1] III. Expected Outcomes
Minimum of 21 mbar pressure shall be achieved from 30 m/sec
I. Problem Statement inlet velocity by maintaining length of the laid network of GI
During this process various factors need to be considered to (Galvanized Iron) and PE (Polyethylene) pipes.
maintain required pressure and velocity at consumer end with
minimal losses. The factors which need to be taken into account

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
IV. Literature Review fields of the gas in both models with their differences. The
Many researches have contributed to the Study of Natural Gas entire research is based on the elimination of any inaccuracy
Pipeline and its Planning and Laying, some of the Papers are which should appear in the flow of the natural gas measured in
summarized below: the high-pressure pipelines of the gas industry and which is
currently not given in the relevant standard.[4]
1. CFD investigation of natural gas leakage and propagation
from buried pipeline for anisotropic and partially saturated 4. Z.A. Majid a, R. Mohsin a, Z. Yaacob a, Z. Hassan in
multilayer soil Javad Bezaatpour Esmaeil Fatehifar in the ‘Failure analysis of natural gas pipes ‘Study was performed to
present study, the 3-D model of natural gas leakage from a identify the most probable cause of the pipe’s failures. The
buried damaged pipeline in the soil is studied numerically by study conducted by reviewing the existing design and
utilizing the finite element method under unsteady-state construction data, visual physical inspection, pipe material
condition until it reaches the soil surface. The characteristics of analysis, structural analysis using NASTRAN and
the porous media are considered in accordance with the actual Computational Fluid Dynamics analysis (CFD) using
soil conditions. As a novel idea the employed soil is considered FLUENT. Investigations revealed that high pressure water jet
completely anisotropic, stratified with variable moisture from leaked water pipe had completely mixed with surrounding
content for each layer. The weight effect of soil layers is also soil forming water soil slurry (high erosive properties) formed
considered in the model[2] at a close vicinity of these pipes. Continuous impaction of this
slurry upon the API LX42 pipe surface had caused losses of the
2. Miguel Ferreira Santos in ‘Analysis of transient flow in pipe coating materials. Corrosion quickly ensued and material
natural gas transmission network’ presents a mathematical loss was rapid because of the continuous erosion of oxidized
model and its numerical implementation for the simulation of material that occurred simultaneously. This phenomenon
complex gas networks in transient state, including the explains the rapid thinning of the steel pipe body which later
mathematical formulation, the experimental validation and the led to its failure. Metallurgical study using photomicrograph
application to relevant case studies for the Portuguese natural shows that the morphology of the steel material was consistent
gas transmission network. The mathematical formulation is and did not show any evidence of internal corrosion or micro
based upon the principles of conservation, applied to the gas fractures. The structural and CFD simulation results proved that
flow in a pipe, which will be simplified depending on the the location, rate and the extent of erosion failures on the pipe
assumptions made. The numerical implementation is based on surfaces can be well predicted, as compared with actual
the conservation of mass in a node, by two different numerical instances.
methods: finite difference and finite elements. Two existent
computer programs were improved to perform the numerical Materials Used for CGD
calculations. Two case studies were analyzed. It is concluded
that the developed numerical methods simulate the behavior of A. Medium Density Polyethylene Pipeline (MDPE)
complex networks, with no preference for either method. It is 1. Specification of MDPE Pipe
verified that if pipes are non-horizontal the elevation term
might be nonnegligible. It can also be concluded that the
Portuguese gas network has the capacity to meet the gas
demand in near future.[3]

3. R. Kiš, M. Malcho, M. Janovcova in ‘A CFD Analysis of

Flow through a High-pressure Natural Gas Pipeline with an
Undeformed and Deformed Orifice Plate’ aims to present a
numerical analysis of the natural gas which flows through a
high-pressure pipeline and an orifice plate, through the use of
CFD methods. The paper contains CFD calculations for the Fig 1: Medium Density Polyethylene Pipeline

flow of natural gas in a pipe with different geometry used for

The Medium density Polyethylene (MDPE) Pipe that has been
the orifice plates. One of them has a standard geometry and a
used has some of the specifications as follows:
shape without any deformation and the other is deformed by the
action of the pressure differential. It shows the behavior of
natural gas in a pipeline using the velocity profiles and pressure

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
• Tech Spec: IS 14885:2001 & ISO 4437 V. Design
• Material Grade & Color: Internationally approved B. For MDPE Pipe
resins of PE 100 grade of orange color The length of the MDPE pipe that needs to be used is calculated
• Minimum Required Strength (MRS) of PE 100 grade on the basis of the Weymouth equation.
pipe: 10 MPa The Weymouth Equation for MDPE is:
• Pressure Class: SDR 9 (dia 20 mm), SDR 11 (dia 32 Q = 0.11672 * (d)*2.664 * {(p12-p22)0.544 / (S * L)1/2}
& 63 mm) and SDR 17.6 (dia 90, 110, 125 and 160 Where,
mm). d = diameter of pipe
• Operating pressure: 4 bar (g) p12=inlet Pressure
• Operating temperature range: - 10°C to + 40°C. p22=outlet Pressure
• Density: > 930kg/m^3 S = specific density of Natural Gas
L = length of pipe laid
• Tensile Strength at Yield elongation: 15MPa

Velocity, V = Q / A
A. Galvanized Iron Pipes
Note: Velocity for filtered gas to be 30 m/s &
1. Specification of GI Pipe
unfiltered gas to be 20 m/s.

C. For GI Pipe
The length of the GI pipe that needs to be used is calculated on
the basis of the Weymouth equation.
The Poly flow Equation for GI is:
Q = 1.522786 * 10-3 * (d)2.623 * {(h/L)0.541}
Where,
d = diameter of pipe
h = height of building
L = length of pipe laid
Being a standard PNG Connection, we have standardized the
design of PNG Network as follows;
• Peak Gas flow is assumed @ 0.5 SCMH for one house
• ½” GI pipes up to G + 4 apartments OR 5 connections in case
of row house.
•1” GI Pipe above 5th Floor apartment OR above five
connections in row house.

VI. Pipe Laying Procedure

Fig 2: GI Pipe
A. For MDPE Pipe
The Galvanized Iron (GI) Pipe that has been used has some of 1. Route Planning
the Specifications as follows: Route Planning is the first Process when it comes to the MDPE
pipe laying Process. Route Planning Ensures that the Process of
• Tech Spec: IS 1239 (Part 1) trenching is smooth. It avoids any obstacles that are laid under
• Types used: Medium Class and Heavy Class the planning area.
• Pipes shall be screwed with Taper threads
2. Trenching
• Threads: Tapered and conforming to BS 21
Trenching Is the Process of making a 0.4m wide trench and
• Galvanizing: IS 4736
1.2m deep for laying of MDPE pipeline with the help of
• Coating requirements: Mass of coating is 400 g / m2
trenching tools. It can be done either manually with labors or
• Test Pressure: 5 MPa
by the help of bulldozers if necessary.
• Powder Material: Pure Polyester
• Application: Electrostatic spraying (40 – 90 KV,
Manual / Automatic)

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
3. Laying Then it is Checked for any Leakage. If any Leakage is found it
In the laying process the MDPE pipe is laid into the trench with is rectified or else the pressure is released. Painting with yellow
proper orientation and backfilling is done. A warning mat is laid color is done after the testing.
on top of the laid pipe as a warning symbol for safety purposes.
VII. Computer Aided Drawing Using Solid Works
4. Joining
The joining Process is Done with the help of a fusion machine. After a design has been selected, the next step in designing
The fusion machine used is of GF. It is connected to two end process is 3D model. The design is separated into part by
pieces of the connection point where it needs to be joined. The part and the dimensioning process is firstly sketched on the
time taken for joining MDPE pipe is 315 sec. paper. After dimensioning, the drawing of the design is
drawn using computer software Solidworks. At this stage,
5. Backfilling. solid modelling method is used. Part by part solid
Backfilling is carried out from the extracted material for the modelling creates according to the dimension done before,
laying of the pipeline. the ends of the laid pipe are kept open after all part create, the 3D model is assembled with each
for the testing and purging. other base on the design.

6. Testing
Testing is carried out for detection of any Leakages throughout
the laid pipe. The testing is done for the pressure of 6.2 Kg/cm2
for about 24 Hrs. No leakages were detected during the testing.

7. Restoration
Restoration is a process of installation of the tiles and PCC
during the Excavation of the ground for which the pipe has been
laid. PCC is used in the ratio of 1:2:4 for the restoration purpose
Fig 3: Low Pressure Pipe
8. Marker Installation
As the laid Pipeline need to be identified for the operation and
maintenance purpose route markers are installed for this reason.
The laid Pipeline was then marked by using proper route
markers

B. For GI Pipe
1. Route Survey
Route survey is carried out in order to plan for the installation
of the GI pipe. We have surveyed the building and found out
the appropriate route that the GI pipe needs to be installed.
Obstacles such as wires waterflow pipes are need to be properly
studied in order to carefully plan the surveying process. Fig 4: Galvanized Iron Pipe

2. GI Installation
As per the planning drawings the GI installation is carried out
into the building for the Krushna Chaya building. This is done
by the overhanging plumbers with proper tools and machines
such as Drilling machines. Proper use of the safety equipment’s
is necessary for the installation of these pipes.

3. Testing of GI pipe.
For GI Pipeline the Flushing is done at 250 mbar. The Flushed
pipeline is Kept under pressure (250-300 mbar) for 15 min.

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
Fig 5: Union for GI pipe

Fig 7: Reducer

Fig 6: ½ inch Tee for GI pipe

Table 1: Material Required

A. Boundary Conditions
The Boundary conditions for the analysis were considered for
the given data. Methane at ambient temperature (300K) was
Fig 8: ½ inch valve used as the working fluid. Simulations were carried out by
specifying velocity at the inlet of the horizontal pipeline.
Which is taken to be 30 m/s. Another Boundary condition was
the Pressure at each outlet of the GI valve. The Pressure was
taken to be at Environmental Pressure which is 101.325 Kpa

Table 2: Boundary Conditions

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
B. Results
As observed in table given below the pressure drops across
the designed pipeline are:

Table 3: Results

Fig 11: Pressure Surface Plot across the planned pipe of Krushna Chaya
Fig 9: Inlet Flow Velocity

Fig 12: Velocity Surface Plot across the Planned pipe of Krushna Chaya
Fig 10: Pressure Surface Plot across the planned pipe of Krushna Chaya

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 International Journal of Engineering and Techniques - Volume 7 Issue 3, June 2021
VIII. Conclusions https://www.researchgate.net/publication/245161740_Failure_
analysis_of_natural_gas_pipes
Using CFD analysis the minimum pressure throughout the
constructed pipeline was observed to be 2560.14 Pa which was [6] Development of natural gas flow rate in pipeline networks
found at the outlet of the constructed pipeline. The average based on unsteady state Weymouth Equation-Hossein Amani,
Pressure is maintained is 11461.73 Pa for the constructed Hasan Kariminezhad, Hamid Kazemzadeh,2016,
pipeline. It reaches its maximum value at the inlet. sciencedirect.com

To achieve the required pressure at the consumer end, the major

affecting factor for the laid network are the pipe dimensions.

To avoid leakages in the network, fittings must be properly

fused and fitted using proper material and equipment.

To avoid major head losses caused in laid networks we should

use a minimum no. of fittings and also, we need to ensure that
the laid network has minimum no. of joints.

References

[1] Rasel A Sultan, Houssemeddine Leulmi 21st March, 2016.

CFD Simulation Investigation of Natural Gas Components
through a Drilling Pipe.Reserach Gate Publication, 4-5,12
https://www.researchgate.net/publication/299616522_CFD_Si
mulation_Investigation_of_Natural_Gas_Components_throug
h_a_Drilling_Pipe

[2] Ali Rasoulzadeh, Javad Bezaatpour,, Esmaeil Fatehifar –

2016 CFD investigation of natural gas leakage and
propagation from buried pipeline for anisotropic and partially
saturated multilayer soil – 1-10

[3] Miguel Ferreira Santos - Analysis of transient flow in

natural gas transmission network
https://fenix.tecnico.ulisboa.pt/downloadFile/395142220603/r
esumo_51565.pdf

[4] R. Kiš, M. Malcho, M. Janovcová - World Academy of

Science, Engineering and Technology International Journal of
Mechanical and Mechatronics Engineering Vol:8, No:3, 2014
A CFD Analysis of Flow through a High-Pressure Natural
Gas Pipeline with an Undeformed and Deformed Orifice Plate

https://publications.waset.org/9997799/a-cfd-analysis-of-flow-
through-a-high-pressure-natural-gas-pipeline-with-an-
undeformed-and-deformed-orifice-plate

[5] Zulkifli Abdul Majid, Rahmat Mohsin, Z. Yaacob,

Zulkafli - June 2010 Hassan Failure analysis of natural gas
pipes

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