Raypak 850, 300 operating instructions Gas Supply Connection, Gas Supply Pressure

Gas Supply

DANGER: Make sure the gas on which the heater will operate is the same type as specified on the rat- ing plate.

Gas piping must have a sediment trap ahead of the heater gas controls, and a manual shut-off valve lo- cated outside the heater jacket. It is recommended that a union be installed in the gas supply piping adja- cent to the heater for servicing. The gas supply pressure to the heater must not exceed 10.5 in. WC for natural gas or 13.0 in. WC for propane gas. A pounds- to-inches regulator must be installed to reduce the gas supply pressure if it is higher than noted above. This regulator should be placed a minimum distance of 10 times the pipe diameter upstream of the heater gas controls. Refer to Table J for maximum pipe lengths.

Gas Supply Connection

CAUTION: The heater must be disconnected from the gas supply during any pressure testing of the gas supply system at test pressures in excess of 1/2 psi (3.45 kPa).

The heater must be isolated from the gas supply pip- ing system by closing the upstream manual shut-off valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psi (3.45 kPa). Relieve test pressure in the gas supply line prior to re-connecting the heater and its manual shut-off valve to the gas supply line. FAILURE

TO FOLLOW THIS PROCEDURE MAY DAMAGE THE GAS VALVE. Over-pressurized gas valves are not covered by warranty. The heater and its gas con- nections shall be leak-tested before placing the appliance in operation. Use soapy water for leak test. DO NOT use an open flame.

CAUTION: Do not use Teflon tape on gas line pipe thread. A pipe compound rated for use with natural and propane gases is recommended. Apply sparingly only on male pipe ends, leaving the two end threads bare.

CAUTION: Support gas supply piping with hangers, not by the heater or its accessories. Make sure the gas piping is protected from physical damage and freezing, where required.

Gas Supply Pressure

A minimum of 4.0 in. WC and a maximum of 10.5 in. WC upstream gas pressure is required under load and no-load conditions for natural gas. A minimum of 4.0 in. WC and a maximum of 13.0 in. WC is required for propane gas. The gas pressure regulator(s) supplied on the heater is for low-pressure service. If upstream pressure exceeds these values, an intermediate gas pressure regulator, of the lockup type, must be installed.

When connecting additional gas utilization equipment to the gas piping system, the existing piping must be checked to determine if it has adequate capacity for the combined load. The gas valve pressure regulator on the heater is nominally preset as noted in Table I.

During normal operation, carbon dioxide should be 8.5 to 9.0% at full fire for natural gas and between 9.0 and 9.5% for propane gas. Carbon monoxide should be ‹150 ppm.

Model	Manifold Pressure (in. WC)
	Natural Gas		Propane Gas
No.
	High	Low	High	Low
300	-0.2	-0.1	-0.2	-0.1
500	-0.3	-0.1	-0.3	-0.1
850	-3.2	-0.2	-2.7	-0.1

NOTE: Manifold pressures should be ±0.3 in. WC.

Table I: Manifold Gas Pressure Settings

Fig. 10: Gas Supply Connection

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