Water Connection Installation; Unitherm Governor Operation; Internal Automatic Bypass Valve - Raypak 408 Installation And Operation Manual

5.7. Water Connection Installation

Gather the loose items that were shipped with the heater.
Figure 19. Water Connection Components
The components should be assembled onto the inlet and
outlet header of the unit as shown below.
Figure 20. Water Connection Assembly
Once all components are in place and installed properly,
the water connections will appear as shown below:
Figure 21. Water Connection Installation
18
The heater must be located so that any water leaks will not
damage the structure of adjacent area. High temperature
2" plastic pipe (CPVC) may be threaded directly into the
header flanges. This is not the same as the Schedule 80
PVC pipe which is also gray. PVC may be used immediately
after the supplied CPVC adapters.
DO NOT use petroleum-based assembly fluids (such
as petroleum jelly or lubricating oil). If assembly lube is
required, use a silicon base such as AquaLube etc.

5.8. Unitherm Governor Operation

CAUTION: The patented Unitherm Governor is a
A
thermostatic mixing valve specifically designed to
maintain constant heater internal temperature between
105° (41°C) and 115°F (46°C) despite continually changing
flow rates from the filter and changing pool temperatures.
This narrow range is needed to prevent damaging
condensation on the burners which will occur if the
heater runs for any length of time below 100°F (38°C). It
is also needed to inhibit scale formation in the tubes by
maintaining temperatures well below accelerated scaling
temperatures.
UG PLUG
Figure 22. Unitherm Governor Valve

5.9. Internal Automatic Bypass Valve

In addition to the Unitherm Governor, a built-in automatic
bypass valve is provided in the in/out header. While the
Unitherm Governor responds to the changes in water
temperature in the heater, the internal bypass valve
automatically responds to changes in water pressure in the
piping system. Proper amount of water flow is maintained
through the heater under varying pressures dictated by
the conditions of the pump and filter.
GASKET
(BEHIND UG)
UNITHERM
GOVERNOR
UG SPRING