Flow Rate Chart for Orifice Union Hole Sizes (Gallons Per Minute)

Differential Pressure (PSI)	Velocity of Discharge in Feet per second "C" = 0.61	Diameter of Orifice in Inches
		1/64"	1/32"	1/16"	1/8"	3/16"	1/4"	3/8"	1/2"	5/8"	3/4"	7/8"	1"
1	7.45	0.0046	0.0186	0.072	0.286	0.642	1.140	2.560	4.560	7.130	10.250	14.000	18.250
2	10.50	0.0064	0.0263	0.103	0.408	0.908	1.610	3.620	6.450	10.05	14.500	19.750	18.250
3	12.95	0.0081	0.0324	0.125	0.496	1.118	1.980	4.460	7.950	12.40	17.850	24.300	31.800
4	14.90	0.0093	0.0372	0.144	0.573	1.280	2.280	5.130	9.120	14.30	20.500	28.000	36.600
5	16.70	0.0104	0.0418	0.161	0.640	1.440	2.560	5.750	10.02	16.00	23.000	31.400	41.000
6	18.20	0.0113	0.0455	0.176	0.700	1.570	2.780	6.280	11.15	17.48	25.100	34.200	44.700
7	19.75	0.0123	0.0493	0.191	0.760	1.700	3.020	6.800	12.05	18.90	27.200	37.200	48.400
8	21.10	0.0132	0.0527	0.204	0.812	1.820	3.230	7.280	12.90	20.20	29.100	39.700	51.800
9	22.20	0.0139	0.0550	0.215	0.853	1.910	3.400	7.650	13.60	21.30	30.600	41.700	54.500
10	23.60	0.0147	0.0590	0.230	0.940	2.030	3.610	8.130	14.45	22.50	32.400	44.200	57.700
20	33.40	0.0209	0.0835	0.317	1.280	2.860	5.100	11.50	20.40	31.90	45.700	63.200	81.800
30	40.80	0.0255	0.1020	0.392	1.560	3.510	6.230	14.05	25.00	39.00	56.200	76.400	100.00
40	47.20	0.0294	0.1180	0.452	1.810	4.050	7.220	16.20	28.90	45.00	64.800	88.600	115.50
50	52.60	0.0329	0.1320	0.507	2.020	4.530	8.070	18.10	32.30	50.40	72.700	99.000	129.00
60	57.60	0.0361	0.1440	0.550	2.210	4.960	8.850	19.85	35.30	55.20	79.300	108.00	141.00
70	62.40	0.0390	0.1560	0.598	2.390	5.360	9.600	21.50	38.10	59.70	86.000	116.50	153.00
80	66.70	0.0417	0.1670	0.642	2.550	5.700	10.20	23.00	40.80	63.50	91.800	125.60	163.00
90	70.50	0.0440	0.1765	0.678	2.710	6.070	10.80	24.40	43.30	68.00	97.700	132.80	173.00
100	74.50	0.0465	0.1865	0.716	2.850	6.400	11.40	25.70	45.60	85.00	123.00	165.00	212.00
200	105.0	0.0655	0.2630	1.010	4.030	9.100	16.10	36.30	64.60	101.00	145.00	197.50	258.00
300	129.5	0.0810	0.3240	1.230	4.940	11.10	19.80	44.50	79.50	123.50	178.00	243.00	317.00
400	149.0	0.0930	0.3720	1.440	5.730	12.85	22.80	51.30	91.80	143.00	205.00	280.00	367.00
500	166.0	0.1038	0.4150	1.600	6.350	14.30	25.40	57.40	104.00	159.00	229.00	312.00	410.00
600	183.0	0.1140	0.4570	1.770	7.040	15.75	28.10	63.00	112.50	176.00	252.00	345.00	450.00
700	198.0	0.1235	0.4950	1.930	7.640	17.00	30.40	68.40	121.50	189.00	274.00	372.00	488.00
800	212.0	0.1330	0.5300	2.050	8.130	18.25	32.30	73.00	130.00	203.00	292.00	398.00	522.00
900	225.0	0.1405	0.5630	2.180	8.600	19.40	34.40	77.50	138.00	216.00	310.00	423.00	553.00
1000	236.0	0.1480	0.5850	5.280	9.050	20.30	36.00	81.30	144.00	226.00	325.00	443.00	578.00
1100	247.0	0.1540	0.6170	2.380	9.470	21.20	37.70	85.00	152.50	236.00	341.00	464.00	607.00
1200	258.0	0.1620	0.6470	2.500	9.940	22.30	39.60	89.00	158.70	247.00	356.00	487.00	635.00
1300	269.0	0.1680	0.6720	2.600	10.30	23.20	41.00	93.00	165.00	256.00	369.00	505.00	660.00
1400	278.0	0.1730	0.6960	2.700	10.68	24.10	42.80	96.00	170.00	266.00	385.00	525.00	688.00
1500	288.0	0.1800	0.7200	2.790	11.05	24.90	44.00	99.00	176.50	275.00	396.00	542.00	710.00
1600	298.0	0.1860	0.7450	2.880	11.48	25.60	45.60	102.50	182.00	285.00	410.00	561.00	738.00
1700	307.0	0.1920	0.7650	2.980	11.85	26.50	46.90	106.00	188.00	294.00	424.00	578.00	759.00
1800	316.0	0.1970	0.7950	3.070	12.15	27.40	48.40	109.00	194.00	303.00	437.00	597.00	783.00
1900	325.0	0.2030	0.8140	3.150	12.45	28.00	49.70	112.00	199.00	311.00	449.00	610.00	800.00
2000	334.0	0.2090	0.8350	3.240	12.80	28.80	51.00	115.00	204.00	320.00	458.00	628.00	824.00
2500	373.0	0.2330	0.9300	3.610	14.30	32.20	57.00	128.50	222.00	358.00	515.00	700.00	915.00
3000	408.0	0.2550	1.0200	3.940	15.60	35.70	62.30	140.00	250.00	390.00	563.00	770.00	1005.00
Volumes given are based on the following coefficients: Contraction Coefficient = 0.620 Velocity Coefficient = 0.985 Discharge Coefficient (0.620 x 0.9851) = 0.61