PVI Industries PV500-47C Multiple Unit Installations Gas Piping Size Chart, Nominal Iron, Inches

MULTIPLE UNIT INSTALLATIONS GAS PIPING SIZE CHART

Maximum Capacity of Pipe in Thousands of BTU’s per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and a pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025BTU’s per Cubic

Foot of Gas and 0.60 Specific Gravity).

Nominal Iron							Length of Pipe in Straight Feet
Pipe Size,
Inches		10	20	30	40	50	60	70	80	90	100	125	150	175	200
3/4		369	256	205	174	155	141	128	121	113	106	95	86	79	74
	1	697	477	384	328	292	267	246	256	210	200	179	164	49	138
1	1/4	1400	974	789	677	595	543	502	472	441	410	369	333	308	287
1	1/2	2150	1500	1210	1020	923	830	769	707	666	636	564	513	472	441
	2	4100	2820	2260	1950	1720	1560	1440	1330	1250	1180	1100	974	871	820
2	1/2	6460	4460	3610	3100	2720	2460	2310	2100	2000	1900	1700	1540	1400	1300
	3	11200	7900	6400	5400	4870	4410	4000	3800	3540	3300	3000	2720	2500	2340
	4	23500	16100	13100	11100	10000	9000	8300	7690	7380	6870	6150	5640	5130	4720

7.6Appliance Isolation during Gas Supply Piping Pressure Test

1.The appliance and its provided manual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of ½ PSI (3.5 kPa).

2.The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or less than ½ PSI (3.5 kPa).

3.The appliance and its gas connection must be leak-tested before placing it in operation.

7.7Gas Connection

1.Safe operation of unit requires adequate gas supply with the required static and dynamic (flow) pressures. Actual piping selection depends on many variables that must be carefully considered by the gas piping system designer.

Do not select gas pipe sizes based only on the supplied tables. These tables are for use by the gas piping system designer as a reference in checking pipe size selections.

2.Gas pipe size may be larger than heater connection.

3.Installation of a union is suggested for ease of service.

4.Install a manual main gas shutoff valve, outside of the appliance gas connection and before the appliance provided appliance manual shutoff gas valve, when Codes require.

5.The gas system installer should clearly identify the emergency shut-off device.

6.A sediment trap (drip leg) MUST be provided in the inlet of the gas connection to the unit.

7.The code compliant vent limiters are designed and must respond to pressure changes in the installation environment, as opposed to outdoor pressure. For proper operation, do not connect to outdoor atmosphere.

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PV500-47C 06/12