Raypak P-4001, P-1826, P-926 Venting of Diaphragm Gas Components, Model, 1-1/4”, 1-1/2”, 2-1/2”

MANUAL	MANOMETER
SHUTOFF
VALVE

GAS PRESSURE

TEST UPSTREAM

GAS PRESSURE

TEST AT GAS

VALVE

GAS PRESSURE TEST

AT HEATER

Fig. 6: Gas Pressure Test Points

Venting of Diaphragm Gas

Components

Heaters with gas train components that have diaphragms in their construction are supplied with a bleed line connection that must be connected to the outside atmosphere as required by the National Fuel

Gas Code. Under NO circumstances shall bleed lines terminate in the gas utilization equipment flue or exhaust system.

Bleed Line

Connection

Fig. 7: Bleed Line Connection

Model	N	1”	P	1-1/4”		1-1/2”		N	2”	P	2-1/2”		N	3”	P	N	4”	P
No.				N	P	N	P				N	P
926/962			15	20	45	45	110	150		360	400
1083/1125			10	15	35	35	80	120		300	300
1178/1223					25	25	60	85		220	200	325	560
1287/1336					25	20	55	75		180	170
1414/1468					20	15	45	65		150	165	300	500
1571/1631					15	15	35	50		20	125	250	400
1758/1826					15	10	30	40		100	100	225	340
2100					10	10	25	30		80	75	175	260		400	600
2500							15	20		55	55	135	160
3001							10	15		35	40	85	120		250	500		600
3500								10		30	30	45	80		200	400
4001								5		20	25	35	65		160	300		400

Natural Gas, 1000 BTU/FT3 .60 Specific Gravity @ 0.5 in. WC Pressure Drop

Propane Gas, 2500 BTU/FT3 1.53 Specific Gravity @ 0.6 in. WC Pressure Drop

Table B: Maximum Equivalent Pipe Length

9