Raypak 5042004 Relief Valve Piping, Temperature & Pressure Gauge, Hydrostatic Test

CAUTION: This heater requires forced water circulation when the burner is operating. See Table F and Table G for minimum and maximum flow rates and water pump selection. The pump must be interlocked with the heater to prevent heater operation without water circulation.

NOTE: Minimum pipe size for in/out connections is 2 in. NPT for 504 and 754 models and 2-1⁄2in NPT for 1104–2004 models. Verify proper flow rates and ∆T as instructed in this manual.

Relief Valve Piping

WARNING: Pressure relief valve discharge piping must be piped near the floor and close to a drain to eliminate the potential of severe burns. Do not pipe to any area where freezing could occur. Refer to local codes.

Temperature & Pressure Gauge

The temperature and pressure gauge is shipped loose for field installation and must be installed within 12 inches of the boiler outlet (if possible) in an easily readable location. Installation must comply with ASME Section IV as well as all applicable national, state and local codes.

Hydrostatic Test

Unlike many types of heaters, this heater does not re- quire hydrostatic testing prior to being placed in operation. The heat exchanger has already been fac- tory-tested and is rated for 160 psi operating pressure. However, Raypak does recommend hydrostatic test- ing of the piping connections to the heater and the rest of the system prior to operation. This is particularly true for hydronic systems using expensive glycol- based anti-freeze. Raypak recommends conducting the hydrostatic test before connecting gas piping or electrical supply.

Leaks must be repaired at once to prevent damage to the heater. NEVER use petroleum-based stop-leak compounds.

To perform hydrostatic test:

1.Connect fill water supply. With bleed valve open, fill heater with water. When water flows from bleed valve, shut off water. Close bleed valve. Carefully fill the rest of the system, making sure to eliminate any entrapped air by using high-point vents. Close

feed valve. Test at standard operating pressure for at least 24 hours.

2.Make sure constant gauge pressure has been maintained throughout test.

3.Check for leaks. Repair if found.

Cold Water Operation

CAUTION: Damage due to internal condensation may occur if the heater inlet water temperature does not exceed 120°F (49°C) within 7 minutes of start- up.

This heater is equipped with a proprietary condensate evaporation system which will evaporate any conden- sate that may begin to accumulate inside the primary heat exchanger with water temperatures as low as 120°F (49°C).

Heaters operated with an inlet temperature of less than 120°F (49°C) MUST have a manual bypass (see Fig. 16) or an approved low-temperature operation system (Figs. 9 and 10) to prevent problems with con- densation. This piping is similar to a primary/secondary boiler installation, with a bypass acting as the secondary boiler piping. Raypak strong- ly recommends that thermometer(s) be placed into the heater piping next to the in/out header to facilitate tem- perature adjustment. Inlet water temperatures below 120°F (49°C) can excessively cool the products of combustion, resulting in collection of condensate in the heat exchanger area beyond the capacity of the con- densate evaporation system.

Failure to reach or exceed 120°F (49°C) within 7 min- utes may damage or cause failure of the heat exchanger, combustion chamber, or other parts within the combustion chamber. It can cause operational problems, bad combustion, sooting, flue gas leakage and reduced service life of the appliance and the vent system. A bypass allows part of the heater discharge water to be mixed with the cooler water returning to the heater inlet to increase the heater inlet temperature above 120°F (49°C). This precautionary measure should prevent the products of combustion from con- densing beyond the ability of the condensate management system employed in this heater in most installations. Warranty claims will be denied for damage or failures caused by condensation.

Cold water operation issues are applicable to both cold water start and cold water run applications. Cold water operation for 7 minutes or less on initial daily start-up is acceptable. Where cold water starts will last

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