Steel Pipes Schedule 40 - Pressure Loss

The tables below can be used to estimate friction loss or pressure drop for water flowing through ASME/ANSI B36.10/19 schedule 40 steel pipes.

The pressure drop calculations are based on the D'Arcy-Weisbach Equation with the following parameters:

• Fluid : Water
• Pipe : Steel Pipe - Schedule 40
• Temperature : 20.0 ^oC (68.0 ^oF)
• Density : 998.3 kg/m³ (62.0 lb/ft³)
• Kinematic Viscosity : 1.004×10^-6 m²/s (0.01 stokes) (1.08×10^-5 ft²/s)
• Pipe Roughness Coefficient : 4.5×10^-5

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Nominal Pipe Size: 3/8"

• Inside Diameter: 0.0125 m (0.49 inches)

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Nominal Pipe Size: 1/2"

• Inside Diameter: 0.0158 m (0.62 inches)

Nominal Pipe Size: 3/4"

• Inside Diameter: 0.021 m (0.82 inches)

Nominal Pipe Size: 1"

• Inside Diameter: 0.027 m (1.05 inches)

Nominal Pipe Size: 1 1/4"

• Inside Diameter: 0.035 m (1.38 inches)

Nominal Pipe Size: 1 1/2"

• Inside Diameter: 0.041 m (1.61 inches)

Nominal Pipe Size: 2"

• Inside Diameter: 0.053 m (2.1 inches)

Nominal Pipe Size: 2 1/2"

• Inside Diameter: 0.063 m (2.5 inches)

Nominal Pipe Size: 3"

• Inside Diameter: 0.078 m (3.1 inches)

Nominal Pipe Size: 3 1/2"

• Inside Diameter: 0.09 m (3.548 inches)

Nominal Pipe Size: 4"

• Inside Diameter: 0.102 m (4.0 inches)

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Nominal Pipe Size: 5"

• Inside Diameter: 0.128 m (5.0 inches)

Nominal Pipe Size: 6"

• Inside Diameter: 0.154 m (6.1 inches)

Nominal Pipe Size: 8"

• Inside Diameter: 0.2 m (8.0 inches)

A diagram presentation of the tables above can be found in "Steel Pipe Schedule 40 - Friction loss and Velocity Diagram".

Nominal Pipe Size: 10" 

• Inside Diameter: 0.25 m (10.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 10"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.014	14.2	225	0.28	0.91	300	31	0.01	0.03
0.015	15.0	238	0.30	0.97	300	31	0.01	0.03
0.016	15.8	251	0.31	1.0	400	41	0.02	0.04
0.017	16.7	264	0.33	1.1	400	41	0.02	0.04
0.018	18.3	291	0.36	1.2	500	51	0.02	0.05
0.020	20.0	317	0.39	1.3	600	61	0.03	0.06
0.022	21.7	344	0.43	1.4	700	71	0.03	0.07
0.023	23.3	369	0.46	1.5	800	82	0.04	0.08
0.025	25.0	396	0.49	1.6	900	92	0.04	0.09
0.027	26.7	423	0.52	1.7	1000	102	0.04	0.10
0.028	28.3	449	0.56	1.8	1100	112	0.05	0.11
0.030	30.0	476	0.59	1.9	1200	122	0.05	0.12
0.032	31.7	502	0.62	2.0	1400	143	0.06	0.14
0.033	33.3	528	0.66	2.1	1500	153	0.07	0.15
0.037	36.7	581	0.72	2.4	1800	184	0.08	0.18
0.040	40.0	634	0.79	2.6	2100	214	0.09	0.21
0.043	43.3	687	0.85	2.8	2400	245	0.11	0.25
0.047	46.7	740	0.92	3.0	2800	286	0.12	0.29
0.050	50.0	793	0.98	3.2	3200	326	0.14	0.33
0.058	58.3	924	1.1	3.8	4200	428	0.19	0.43
0.067	66.7	1057	1.3	4.3	5400	551	0.24	0.55
0.075	75.0	1189	1.5	4.8	6800	693	0.30	0.69
0.083	83.3	1320	1.6	5.4	8300	846	0.37	0.85
0.10	100	1585	2.0	6.4	11700	1193	0.52	1.2
0.12	117	1850	2.3	7.5	15700	1601	0.69	1.6
0.13	133	2113	2.6	8.6	20300	2070	0.90	2.1
0.15	150	2378	2.9	9.7	25500	2600	1.1	2.6
0.17	167	2643	3.3	10.7	31200	3181	1.4	3.2
0.20	200	3170	3.9	12.9	44400	4527	2.0	4.5
0.23	233	3698	4.6	15.0	59900	6108	2.6	6.1
0.27	267	4228	5.2	17.2	77600	7913	3.4	7.9
0.30	300	4756	5.9	19.3	97600	9952	4.3	10.0
0.33	333	5283	6.6	21.5	119900	12226	5.3	12.2
0.42	417	6606	8.2	26.9	185600	18926	8.2	19.0
0.50	500	7926	9.8	32.2	265500	27073	11.7	27.1
0.58	583	9246	11.5	37.6	359600	36668	15.9	36.7
0.67	667	10569	13.1	43.0	467900	47712	20.7	47.8
0.75	750	11889	14.7	48.3	590400	60203	26.1	60.3
0.83	833	13209	16.4	53.7	727000	74132	32.1	74.3

Nominal Pipe Size: 12"

• Inside Diameter: 0.300 m (12.0 inches)

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Steel Pipes Schedule 40 - Pressure Loss 12"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.02	20.0	317	0.28	0.91	200	20.4	0.009	0.02
0.02	21.7	344	0.30	0.98	300	30.6	0.01	0.03
0.02	23.3	370	0.32	1.1	300	30.6	0.01	0.03
0.03	25.0	396	0.35	1.1	400	40.8	0.02	0.04
0.03	26.7	423	0.37	1.2	400	40.8	0.02	0.04
0.03	28.3	449	0.39	1.3	500	51.0	0.02	0.05
0.03	30.0	476	0.42	1.4	500	51.0	0.02	0.05
0.03	31.7	502	0.44	1.4	600	61.2	0.03	0.06
0.03	33.3	528	0.46	1.5	600	61.2	0.03	0.06
0.04	36.7	581	0.51	1.7	800	81.6	0.04	0.08
0.04	40.0	634	0.55	1.8	900	91.8	0.04	0.09
0.04	43.3	687	0.60	2.0	1000	102	0.04	0.10
0.05	46.7	740	0.65	2.1	1200	122	0.05	0.12
0.05	50.0	793	0.69	2.3	1300	133	0.06	0.13
0.06	58.3	925	0.81	2.6	1800	184	0.08	0.18
0.07	66.7	1057	0.92	3.0	2300	235	0.10	0.23
0.08	75.0	1189	1.0	3.4	2800	286	0.12	0.29
0.08	83.3	1321	1.2	3.8	3500	357	0.15	0.36
0.10	100	1585	1.4	4.5	4900	500	0.22	0.50
0.12	117	1850	1.6	5.3	6500	663	0.29	0.66
0.13	133	2108	1.8	6.1	8400	857	0.37	0.86
0.15	150	2378	2.1	6.8	10500	1071	0.46	1.1
0.17	167	2643	2.3	7.6	12900	1315	0.57	1.3
0.20	200	3170	2.8	9.1	18300	1866	0.81	1.9
0.23	233	3698	3.2	10.6	24600	2508	1.1	2.5
0.27	267	4228	3.7	12.1	31800	3243	1.4	3.2
0.30	300	4756	4.2	13.6	40000	4079	1.8	4.1
0.33	333	5283	4.6	15.1	49000	4997	2.2	5.0
0.42	417	6606	5.8	18.9	75700	7719	3.3	7.7
0.50	500	7926	6.9	22.7	108100	11023	4.8	11.0
0.58	583	9246	8.1	26.5	149200	15214	6.6	15.2
0.67	667	10569	9.2	30.3	190000	19374	8.4	19.4
0.75	750	11889	10.4	34.0	239500	24422	10.6	24.5
0.83	833	13205	11.5	37.8	294700	30051	13.0	30.1
0.92	917	14532	12.7	41.6	355600	36261	15.7	36.3
1.00	1000	15852	13.8	45.4	422200	43052	18.7	43.1
1.08	1083	17172	15.0	49.2	494500	50424	21.9	50.5

Nominal Pipe Size: 14"

• Inside Diameter: 0.350 m (14.0 inches)

Steel Pipes Schedule 40 - Pressure Loss 14"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.03	30.0	476	0.34	1.1	300	31	0.013	0.03
0.03	31.7	502	0.36	1.2	400	41	0.018	0.04
0.03	33.3	528	0.38	1.3	400	41	0.018	0.04
0.04	36.7	581	0.42	1.4	500	51	0.022	0.05
0.04	40.0	634	0.46	1.5	600	61	0.027	0.06
0.04	43.3	687	0.50	1.6	600	61	0.027	0.06
0.05	46.7	740	0.54	1.8	700	71	0.031	0.07
0.05	50.0	793	0.57	1.9	800	82	0.035	0.08
0.06	58.3	925	0.67	2.2	1100	112	0.049	0.11
0.07	66.7	1057	0.76	2.5	1400	143	0.062	0.14
0.08	75.0	1189	0.86	2.8	1800	184	0.080	0.18
0.08	83.3	1321	0.96	3.1	2200	224	0.097	0.22
0.10	100	1585	1.1	3.8	3100	316	0.14	0.32
0.12	117	1850	1.3	4.4	4100	418	0.18	0.42
0.13	133	2108	1.5	5.0	5300	540	0.23	0.54
0.15	150	2378	1.7	5.6	6600	673	0.29	0.67
0.17	167	2643	1.9	6.3	8000	816	0.35	0.82
0.20	200	3170	2.3	7.5	11400	1162	0.50	1.2
0.23	233	3698	2.7	8.8	15300	1560	0.68	1.6
0.27	267	4228	3.1	10.0	19200	1958	0.85	2.0
0.30	300	4756	3.4	11.3	24800	2529	1.1	2.5
0.33	333	5283	3.8	12.5	30400	3100	1.3	3.1
0.42	417	6606	4.8	15.7	46800	4772	2.1	4.8
0.50	500	7926	5.7	18.8	66800	6812	3.0	6.8
0.58	583	9246	6.7	21.9	90300	9208	4.0	9.2
0.67	667	10569	7.6	25.1	117200	11951	5.2	12.0
0.75	750	11889	8.6	28.2	147700	15061	6.5	15.1
0.83	833	13205	9.6	31.3	181600	18518	8.0	18.5
0.92	917	14532	10.5	34.5	219100	22342	9.7	22.4
1.0	1000	15852	11.5	37.6	260000	26512	11.5	26.6
1.1	1083	17172	12.4	40.7	304400	31040	13.5	31.1
1.2	1167	18495	13.4	43.9	352300	35924	15.6	36.0
1.3	1250	19815	14.3	47.0	403700	41165	17.8	41.2
1.3	1333	21135	15.3	50.1	458600	46763	20.3	46.8

Nominal Pipe Size: 16"

• Inside Diameter: 0.400 m (16.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 16"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.05	50.0	793	0.44	1.4	400	41	0.018	0.04
0.06	58.3	925	0.51	1.7	600	61	0.027	0.06
0.07	66.7	1057	0.59	1.9	700	71	0.031	0.07
0.08	75.0	1189	0.66	2.2	900	92	0.040	0.09
0.08	83.3	1321	0.73	2.4	1100	112	0.049	0.11
0.10	100	1585	0.9	2.9	1600	163	0.07	0.16
0.12	117	1850	1.0	3.4	2100	214	0.09	0.21
0.13	133	2108	1.2	3.8	2700	275	0.12	0.28
0.15	150	2378	1.3	4.3	3400	347	0.15	0.35
0.17	167	2643	1.5	4.8	4100	418	0.18	0.42
0.20	200	3170	1.8	5.8	5800	591	0.26	0.6
0.23	233	3698	2.0	6.7	7800	795	0.34	0.8
0.27	267	4228	2.3	7.7	10100	1030	0.45	1.0
0.30	300	4756	2.6	8.6	12600	1285	0.6	1.3
0.33	333	5283	2.9	9.6	15400	1570	0.7	1.6
0.42	417	6606	3.7	12.0	23800	2427	1.1	2.4
0.50	500	7926	4.4	14.4	33800	3447	1.5	3.5
0.58	583	9246	5.1	16.8	45600	4650	2.0	4.7
0.67	667	10569	5.8	19.2	59200	6037	2.6	6.0
0.75	750	11889	6.6	21.6	74500	7597	3.3	7.6
0.83	833	13205	7.3	24.0	91600	9340	4.0	9.4
0.92	917	14532	8.0	26.4	110400	11257	4.9	11.3
1.0	1000	15852	8.8	28.8	130900	13348	5.8	13.4
1.1	1083	17172	9.5	31.2	153200	15622	6.8	15.6
1.2	1167	18495	10.2	33.6	177300	18079	7.8	18.1
1.3	1250	19815	11.0	35.9	203000	20700	9.0	20.7
1.3	1333	21135	11.7	38.3	230600	23514	10.2	23.6

Nominal Pipe Size: 18"

• Inside Diameter: 0.450 m (18.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 18"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.10	100	1585	0.7	2.3	900	92	0.04	0.09
0.12	117	1850	0.8	2.7	1200	122	0.05	0.12
0.13	133	2108	0.9	3.0	1500	153	0.07	0.15
0.15	150	2378	1.0	3.4	1500	153	0.07	0.15
0.17	167	2643	1.2	3.8	2300	235	0.10	0.23
0.20	200	3170	1.4	4.5	3200	326	0.14	0.3
0.23	233	3698	1.6	5.3	4300	438	0.19	0.4
0.27	267	4228	1.8	6.1	5600	571	0.25	0.6
0.30	300	4756	2.1	6.8	7000	714	0.3	0.7
0.33	333	5283	2.3	7.6	8500	867	0.4	0.9
0.42	417	6606	2.9	9.5	13100	1336	0.6	1.3
0.50	500	7926	3.5	11.4	18600	1897	0.8	1.9
0.58	583	9246	4.0	13.3	25100	2559	1.1	2.6
0.67	667	10569	4.6	15.1	32500	3314	1.4	3.3
0.75	750	11889	5.2	17.0	40900	4171	1.8	4.2
0.83	833	13205	5.8	18.9	50200	5119	2.2	5.1
0.92	917	14532	6.4	20.8	60400	6159	2.7	6.2
1.00	1000	15852	6.9	22.7	71600	7301	3.2	7.3
1.08	1083	17172	7.5	24.6	83800	8545	3.7	8.6
1.17	1167	18495	8.1	26.5	96900	9881	4.3	9.9
1.25	1250	19815	8.7	28.4	110900	11308	4.9	11.3
1.33	1333	21135	9.2	30.3	125900	12838	5.6	12.9

Nominal Pipe Size: 20"

• Inside Diameter: 0.500 m (20.0 inches)

For full table with Pressure Drops - rotate the screen!

Steel Pipes Schedule 40 - Pressure Loss - 20"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.17	167	2643	0.9	3.1	1300	133	0.06	0.13
0.20	200	3170	1.1	3.7	1900	194	0.08	0.2
0.23	233	3698	1.3	4.3	2500	255	0.11	0.3
0.27	267	4228	1.5	4.9	3200	326	0.14	0.3
0.30	300	4756	1.7	5.5	4100	418	0.2	0.4
0.33	333	5283	1.9	6.1	5000	510	0.2	0.5
0.42	417	6606	2.3	7.6	7600	775	0.3	0.8
0.50	500	7926	2.8	9.1	10800	1101	0.5	1.1
0.58	583	9246	3.3	10.7	14500	1479	0.6	1.5
0.67	667	10569	3.7	12.2	18700	1907	0.8	1.9
0.75	750	11889	4.2	13.7	23600	2406	1.0	2.4
0.83	833	13205	4.6	15.2	28900	2947	1.3	3.0
0.92	917	14532	5.1	16.8	34800	3549	1.5	3.6
1.00	1000	15852	5.6	18.3	41200	4201	1.8	4.2
1.08	1083	17172	6.0	19.8	48200	4915	2.1	4.9
1.17	1167	18495	6.5	21.3	55700	5680	2.5	5.7
1.25	1250	19815	7.0	22.9	63700	6495	2.8	6.5
1.33	1333	21135	7.4	24.4	72300	7372	3.2	7.4

Nominal Pipe Size: 24"

• Inside Diameter: 0.600 m (24.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 24"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.30	300	4756	1.1	3.7	1600	163	0.1	0.2
0.33	333	5283	1.3	4.2	2000	204	0.1	0.2
0.42	417	6606	1.6	5.3	3000	306	0.1	0.3
0.50	500	7926	1.9	6.3	4300	438	0.2	0.4
0.58	583	9246	2.2	7.4	5700	581	0.3	0.6
0.67	667	10569	2.6	8.4	7400	755	0.3	0.8
0.75	750	11889	2.9	9.5	9300	948	0.4	0.9
0.83	833	13205	3.2	10.5	11400	1162	0.5	1.2
0.92	917	14532	3.5	11.6	13700	1397	0.6	1.4
1.00	1000	15852	3.9	12.6	16200	1652	0.7	1.7
1.08	1083	17172	4.2	13.7	18900	1927	0.8	1.9
1.17	1167	18495	4.5	14.8	21800	2223	1.0	2.2
1.25	1250	19815	4.8	15.8	24900	2539	1.1	2.5
1.33	1333	21135	5.1	16.9	28300	2886	1.3	2.9

Nominal Pipe Size: 32"

• Inside Diameter: 0.800 m (32.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 32"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.50	500	7926	1.1	3.5	900	92	0.0	0.1
0.58	583	9246	1.2	4.0	1300	133	0.1	0.1
0.67	667	10569	1.4	4.6	1600	163	0.1	0.2
0.75	750	11889	1.6	5.2	2000	204	0.1	0.2
0.83	833	13205	1.8	5.8	2500	255	0.1	0.3
0.92	917	14532	1.9	6.3	3000	306	0.1	0.3
1.00	1000	15852	2.1	6.9	3500	357	0.2	0.4
1.08	1083	17172	2.3	7.5	4100	418	0.2	0.4
1.17	1167	18495	2.5	8.1	4700	479	0.2	0.5
1.25	1250	19815	2.6	8.6	5400	551	0.2	0.6
1.33	1333	21135	2.8	9.2	6100	622	0.3	0.6

Nominal Pipe Size: 36"

• Inside Diameter: 0.900 m (36.0 inches)

Steel Pipes Schedule 40 - Pressure Loss - 36"

Flow			Velocity		Pressure Drop
(m3/s)	(liter/s)	(US gpm)	(m/s)	(ft/s)	(Pa/100m)	(mmH2O/100m)	(psi/100ft)	(ftH2O/100ft)
0.75	750	11889	1.2	4.1	1100	112	0.0	0.1
0.83	833	13205	1.4	4.5	1400	143	0.1	0.1
0.92	917	14532	1.5	5.0	1600	163	0.1	0.2
1.00	1000	15852	1.7	5.4	1900	194	0.1	0.2
1.08	1083	17172	1.8	5.9	2300	235	0.1	0.2
1.17	1167	18495	1.9	6.3	2600	265	0.1	0.3
1.25	1250	19815	2.1	6.8	3000	306	0.1	0.3
1.33	1333	21135	2.2	7.3	3400	347	0.2	0.3