Relief Valve Piping - Raypak 992C Installation & Operating Instructions Manual

5. Remove all plumbing fittings to the header. This
will include both inlet and outlet water pipe unions
and the pressure relief valve and drain piping.
6. Remove limits, control bulbs and/or thermocou-
ples.
7. Remove the eight flange nuts and the in/out head-
er from the left-hand side.
8. Remove the eight flange nuts and the return head-
er from the right-hand side.
9. Reverse the headers to the new location.
10. Install NEW red beveled O-rings flush against both
tube sheets with the bevel facing outward.
11. Push the header firmly against the O-rings. Install
and tighten the flange nuts onto the stud bolts until
finger tight.
12. Slowly tighten the flange nuts, starting from the
center nut (number 1) in Fig. 8 and working se-
quentially around the header as indicated. Torque
all nuts to 25 ft/lb. DO NOT OVER-TIGHTEN.
13. Re-route the capillary(s), wiring etc. to the new
location, adding thermal paste and shim to the
capillary well.
Fig. 8: Torque Sequence

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.
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 Protection (CWP)
This heater must operate with a stable inlet tempera-
ture of 105°F (41°C), long periods of operation with
temperatures below 105°F (41°C) can excessively
cool the products of combustion, resulting in collection
of condensate in the heat exchanger, damaging the
heat exchanger, combustion chamber, significantly
reducing the life of the equipment. The following appli-
cations are approved configurations supported by
Raypak for CWP systems.
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
105°F (41°C). This precautionary measure should pre-
vent the products of combustion from condensing in
most installations.
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