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Gas pipe sizing software

Natural or LP Gas Pipe Sizing for Android (a PocketGas)

high & low pressure gas pipeline hydraulic calculations - find flowrate, pipe size & pressure drop

To take a glance at all pocketEngineer software and OS requirements, click Software List.

For Windows OS, see pocketGas.

For common gases pressure drop calculations, see Gases Hydraulics (Windows OS).

Note: aPocketGas (Android) and pocketGas (Windows) are not the same.

a PocketGas (Gas Pipe Sizing Calculator): your mobile design partner for Gas pipe design & sizing

Natural Gas or LPG (propane) pipe sizing for high pressure & low pressure systems is as easy as 1, 2, 3 with aPocketGas (Gas Pipe Sizer) program. aPocketGas calculates gas flowrate, pipe size and pressure drop. The oldest and most common equation - Weymouth equation - is used in the high pressure gas calculation. NFPA model for high pressure calculation is also included. For low pressure gas calculation, NFPA equation is used.

Aim: creating a mobile design environmentfor the practising engineers & designers in today's mobile world.

Results: Instant solutions at your fingertips.

Highlights:

a mobile design tool app for Gas pipeline hydraulics
calculate both High pressure (for infra & building distribution pipeline ) and Low pressure (for building internal pipeline) gas pressure systems
2 models for high pressure calculations: Weymouth and NFPA. 1 model for low pressure calculation: NFPA
options to find flowrate, pipe size and pressure drop / downstream pressure
gas input module with NFPA + IFGC appliance gas input values selection. Convert gas input to flowrate.
pipe size table module. Select nominal or internal pipe diameter from built-in pipe material.
built-in data, guides, etc
individually selectable SI-IP units
for Android OS

The selectable SI-IP units available are:

Design Explained 1: High Pressure System

The Weymouth equation is used for calculating flows and pressure in high pressure gas system. The Weymouth equation does not use Moody friction factor, but uses a pipeline efficiency factor, E. The equation is developed empirically for compressible, turbulent flow with high Reynolds number in long pipelines. The Weymouth equation is one of the oldest and most common equation (as compared to the Panhandle A & B equations) in high pressure gas calculations. The Weymouth equation is considered to be more conservative than the Panhandle A & B equations.

The Weymouth equation in English units is presented as follows (with elevation effects ignored):

It is worth noting that the Weymouth's formula has expressed Moody friction factor as a function of the pipe diameter, i.e. f = 0.008/d1/3.

For NFPA / IFGC formula, refer to NFPA 54 or International Fuel Gas Code.

Design Explained 2: Low Pressure System

For pressure less than 10 kPa (1.5 psi), the following equation presented in SI units from NFPA / ASHRAE is used to determine gas flow capacity. AGA's International Fuel Gas Code (IFGC) uses the same equation.

Q = 0.0001d 2.623 [dP/(C*L)]0.541

where Q = flow rate at 15 oC and 101 kPa (l/s)

d = inside diameter of pipe (mm)

dP = pressure drop (Pa)

C = factor for viscosity, density and temperature

L = pipe length (m)

Design Explained 3: Pipe Size Table

The built-in Pipe Size Table module is designed as a separate module for a quick access to pipe nominal or internal diameters. Making it a greater navigation experience for users, you can select a pipe nominal or internal diameter within the pipe sizing calculation module. The pipe materials available are:

Copper pipe (EN)
Copper pipe (ASTM)
Ductile iron pipe (EN)
Ductile iron pipe (ANSI)
PVC plastic pipe (ASTM)
HDPE pipe (ASTM)
HDPE pipe (ISO)
Steel pipe (EN)
Steel pipe (ANSI)
Stainless steel pipe (ANSI)

Design Explained 4: Gas Input Calculator

In the planning & design process, you often need to convert a given appliance gas input to flowrate for the purpose of pipe sizing. The Gas Input Calculator exactly does this. It is designed to function as a gas input to flowrate converter, or as a appliance gas input calculator. The built-in appliance gas input values are adopted from NFPA + IFGC.

Comparisons: Weymouth vs NFPA / IFGC for Lower End of High Pressure System

Given:

Inlet pressure = 5 psi (gauge), Pressure drop = 3.5 psi, Flowrate = 84656 cfh, Gas = Natural Gas, Specific gravity = 0.6, Pipeline temperature = 60 oF, Pipe = smooth wall.

Gas Sizing Example 1: High Pressure System

Calculate the outlet (downstream) pressure in a 17.5 inch (444.5 mm) natural gas pipeline, 20 miles (32.2 km) long. The gas flow rate is 6,250,000 cfh (176,875 cmh) at a flowing temperature of 70 oF (21.1 oC). The inlet pressure (absolute) is 1014.7 psia (6996.2 kPa) and the gas gravity is 0.6. High Density Polyethylene (HDPE) pipe is used, Assume the pipeline efficiency is 0.98, and compressibility factor is 0.85. Ignore elevation effects.

The following results are computed by aPocketGAS program:

Note: Standard atmospheric conditions used in aPocketGAS program = 520 oR (15 oC) & 14.7 psi (101.3kPa).

Gas Sizing Example 2: Low Pressure System

A restaurant serving about 300 persons requires a total gas demand of 1000 cfh (7.8611 l/s) for its cooking equipment. The total pipe length measured from the gas meter to the restaurant kitchen is 60 ft (18.29 m). Natural gas with 0.60 specific gravity is used. The pressure drop from the gas meter to the kitchen shall not exceed 0.3 in. w.g. (74.6 Pa). Determine the required pipe size.

The following results are computed by aPocketGAS program:

Gas Sizing Example 3: Medium Pressure System

Natural Gas:

Medium gas pressure system with pressure available at point D = 60 psi. The 1st regulator is set to deliver 5 psi at the outlet of the regulator. The upstream piping system shall deliver pressure no less than 20 psi at point A to the 1st regulator. Size the gas pipe line from D to A.

Information available:

Building 1 estimated gas demand = 20,000 cfh

Building 2 estimated gas demand = 20,000 cfh

Building 3 estimated gas demand = 30,000 cfh

Pipe length D-C (including fittings) = 250 ft

Pipe length C-B (including fittings) = 200 ft

PIpe length B-A (including fittings) = 200 ft

Working illustrations (by no means this is the only approach):

Allowable pressure drop from D to A = 60-20 = 40 psi.

Total pipe length from D to A = 650 ft.

Allocate pressure losses equally from D to A. Therefore, pressure loss = 40/650 = 0.0615 psi per ft.

(Note: you can distribute the pressure losses any way you wish as long as the sum of the total pressure drop does not exceed the allowable pressure drop.)