Natural gas calculator

Inputs

Flow rates and velocities

volumetric flow rate at standard conditions (q)

volumetric flow rate at the start of pipeline (q₁)

volumetric flow rate at the end of pipeline (q₂)

mass flow rate (ṁ)

velocity at the start of pipeline (V₁)

velocity at the end of pipeline (V₂)

Pressures

pressure at the start of pipeline (p₁)

pressure at the end of pipeline (p₂)

pressure drop (Δp)

pressure drop per unit of length (Δp/L)

pressure drop due to friction (Δp friction)

pressure drop due to local resistance (Δp local)

Natural gas composition molar ratio of each component

Methane CH4

Ethane C2H6

Propane C3H8

Butane C4H10

Isobutane C4H10

Pentane C5H12

Isopentane C5H12

Hexane C6H14

Carbon dioxide CO2

Nitrogen N2

All components Must be 100%

Mixture properties

Density at standard condition (ρ)

Lower heat value (LHW)

Dynamic viscosity (μ)

Critical pressure (pc)

Specific heat (heat capacity) (cp)

Critical temperature (Tc)

Gas constant (R)

API 5L - Schedule

STD

XXS

List of Pipes

Nominal size [inches]	Outside diameter [inches]	Outside diameter [mm]	Wall thickness [inches]	Wall thickness [mm]	Weight [lb/ft]	Weight [kg/m]
1/8" NPS8	0.405	10.3	0.068	1.73	0.24	0.37
1/4" NPS12	0.54	13.7	0.088	2.24	0.42	0.84
3/8" NPS10	0.675	17.1	0.091	2.31	0.57	0.84
1/2" NPS15	0.84	21.3	0.109	2.77	0.85	1.27
3/4" NPS20	1.05	26.7	0.113	2.87	1.13	1.69
1" NPS25	1.315	33.4	0.133	3.38	1.68	2.5
1 1/4" NPS32	1.66	42.2	0.14	3.56	2.27	3.39
1 1/2" NPS40	1.9	48.3	0.145	3.68	2.72	4.05
2" NPS50	2.375	60.3	0.154	3.91	3.65	5.44
2" 1/2 NPS65	2.875	73.0	0.203	5.16	5.79	8.63
3" NPS80	3.5	88.9	0.216	5.49	7.58	11.29
3 1/2"	4.0	101.6	0.226	5.74	9.11	13.57
4" NPS100	4.5	114.3	0.237	6.02	10.79	16.07
5" NPS125	5.563	141.3	0.258	6.55	14.62	21.77
6" NPS150	6.625	168.3	0.28	7.11	18.97	28.26
8" NPS200	8.625	219.1	0.322	8.18	28.55	42.55
10" NPS250	10.75	273.0	0.365	9.27	40.48	60.31
12" NPS300	12.75	323.8	0.375	9.53	59.56	73.88
14" NPS350	14.0	355.6	0.375	9.53	54.57	81.33
16" NPS400	16.0	406.4	0.375	9.53	62.58	93.27
18" NPS450	18.0	457.0	0.375	9.53	70.59	105.16
20" NPS500	20.0	508.0	0.375	9.53	78.6	117.15
22" NPS550	22.0	559.0	0.375	9.53	86.61	129.13
24" NPS600	24.0	610.0	0.375	9.53	94.62	141.12
26" NPS650	26.0	660.0	0.375	9.53	102.63	152.87
28" NPS700	28.0	711.0	0.375	9.53	110.64	164.85
30" NPS750	30.0	762.0	0.375	9.53	118.65	176.84
32" NPS800	32.0	813.0	0.375	9.53	126.66	188.82
34" NPS850	34.0	864.0	0.375	9.53	134.67	200.31
36" NPS900	36.0	914.0	0.375	9.53	142.68	212.56
38" NPS950	38.0	965.0	0.375	9.53	150.69	223.84
40" NPS1000	40.0	1016.0	0.375	9.53	158.7	235.79
42" NPS1050	42.0	1066.8	0.375	9.53	142.68	212.56
44" NPS1100	44.0	1117.6	0.375	9.53	174.72	259.69
46" NPS1150	46.0	1168.4	0.375	9.53	182.73	271.4
48" NPS1200	48.0	1219.2	0.375	9.53	190.74	283.35
52" NPS1300	52.0	1320.8	0.375	9.53	206.76	307.25
56" NPS1400	56.0	1422.4	0.375	9.53	222.78	330.91
60" NPS1500	60.0	1524.0	0.375	9.53	238.8	355.92
64" NPS1600	64.0	1625.6	0.375	9.53	254.82	379.89

Description

This calculator is intended for the calculation of pressure drop, flow and pipeline dimensions in distribution gas pipelines.

The calculator enables the calculation of natural gas flow by treating it as an incompressible or as a compressible fluid.

In addition to the calculation of the pressure drop due to friction, the calculator also allows the calculation of local resistances in the form of valves or fittings.

The calculation is based on the application of isothermal flow equations, that is, the calculator considers that the gas temperature is the same at the beginning and at the end of the pipeline.

The calculator shows the flow rates at standard and actual conditions, i.e. current pressures and temperatures. The standard conditions are:

Pressure p = 101325 Pa (14.7 psi), and
Temperature 15°C (59°F) for metric units and 60°F for imperial units.

The calculator also shows the actual values of the flow rate at the beginning and end of the pipeline.

The calculator is not intended for calculations where there is a sudden change in pressure or temperature, since such conditions imply adiabatic changes of state.

Action

Calculate for:

Inputs

Mixture properties

API 5L - Schedule

Results

Description

Related links

Input pressure

Input flow

Pressure level

Type of gas flow

Calculation model