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External Auxiliary Bypass Valve
Where Required
- An auxiliary bypass valve should be
used when flow rates exceed 125 GPM (473 lpm). Usually
a high-performance pump size larger than two horsepower
will exceed this flow rate. This valve is required to
complement the function of the automatic bypass valve,
particularly when starting the heater in winter or early
spring when the spa or pool temperature is below 50°F
(10°C). It also serves to eliminate needless pressure drop
through the heater and accompanying reduction in the flow
rate to the spa jets, etc.
FROM HEATER
TO HEATER
TO POOL/SPA
FROM POOL/SPA
FULL PORT
BALL VALVE
OR GLOBE
VALVE
BYPASS VALVE
Do not use gate valve.
Figure 24. Auxiliary Bypass Valve
Auxiliary Bypass Valve Adjustment
To set bypass
- With clean filter, adjustment is made by
feeling the inlet and outlet pipes at the heater. Outlet pipes
should be slightly warmer than inlet and comfortable to the
touch. If pipe is hot, close bypass; if cold, open bypass.
Pressure Relief Valve Installation
To conform to local building codes, it may be necessary
to install a pressure relief valve. A 3/4" pressure relief
valve, having a capacity equal to the BTU output of the
model to be installed, is recommended for this heater. The
maximum acceptable pressure relief valve setting is 125
psi (862 kPa).
A 3/4" NPT connection is provided in the Polymer header
for installation of a pressure relief valve. The valve shall be
installed in a vertical position. Do not over-tighten. Install
pressure relief valve hand tight plus 1/2 turn.
F10662
IN/OUT HEADER
PRV DISCHARGE
CONNECTION
PRESSURE RELIEF VALVE
Figure 25. Field-Supplied Pressure Relief Valve Polymer
Header (Residential Units)
A 3/4" NPT connection is provided in the header for
installation of a 75 PSI (517 kPa) pressure relief valve.
The PRV is shipped loose in the accessory carton with the
pagoda top. The valve pressure relief shall be installed in
a vertical position.
F10663
PRESSURE RELIEF VALVE
Figure 26. Pressure Relief Valve Brass Header
(ASME Models)
NOTE:
To avoid water damage or scalding due to valve
operation, drain pipe must be connected to valve outlet
and run to a safe place of discharge. Drain pipe must
be the same size as the valve discharge connection
throughout its entire length and must pitch downward
from the valve. No shut-off valve shall be installed
between the relief valve and the drain line. Valve lever
should be tripped at least once a year to ensure that
waterways are clear.
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