Crown Mega-Stor 2 Installation Manual

11
B) DOMESTIC SIDE PIPING
BASIC DOMESTIC PIPING
Figure 5.6 shows typical domestic water piping. All components except the control are provided by the installer. The function of
the components shown are as follows:
a) Temperature Control (required) - This control is provided by the factory and must be installed in the control
well location shown in Figure 2.2. Remove the cover and loosen the clamping screw. Apply the silver heat conductive
compound supplied to bulb. Insert the capillary bulb so that it is “bottomed out” in the control well as shown in Figure
5.5 and screw the control clamp securely in the well groove at the end of the well. See Section VI for wiring details and
Section VII for instructions on adjusting the temperature setting.
b) Shut-ovalves(recommended) - Use to isolate the indirect water heater (IWH) for servicing.
c) BackowPreventer(requiredbysomecodes) - Use to prevent water from backing out of the IWH in the event that
inlet water pressure drops.
d) ExpansionTank(requiredwhenabackowpreventerisused)-This expansion tank absorbs the increased volume
causedbyheatingwater.Ifabackowpreventerisinstalled,thisexpansiontankisrequiredbecausetheincreasedwater
volume will otherwise have no place to go and the T&P valve will open. Use an expansion tank designed for use on
domestic water systems. Refer to the expansion tank manufacturer’s literature for the proper size expansion tank to use.
e) Unions (optional) - Use to disconnect the IWH in the event that this is necessary.
f) Drain (Required) - Used to drain the IWH for inspection or servicing. This drain valve is supplied by the installer. For
models MS2-030 through MS2-075, install this valve in the cold water supply where it can be used to drain the tank. A
dedicated drain valve connection is provided on the MS2-119.
g) Temperature/Pressure Relief Valve (“T&P Valve” – Required) - Opens to relieve excess pressure or temperature which
has developed in the Indirect Water Heater’s storage tank. This valve must comply with Z21.22 Standard for Relief
Valves and Automatic Gas Shut-o Devices for Hot Water Supply Systems and must meet the following requirements:
Maximum Pressure Setting - 150psi
Maximum Temperature Setting - 210F
Inlet Size ¾” NPT Male.
Temperature Probe Element length (below male thread) 3 – 8 inches.
Minimum CSA capacity – Per Table 5.7
 NotethatminimumrequiredCSAratingisspeciedinBTU/hranddependsuponthemaximumhighlimitsettingon
the boiler. For low pressure steam boiler installations (where boiler water is drawn from below the water line) use the
221 - 250F column.
Pipe this valve as shown in Figure 5.6. Run the discharge pipe to a location where hot water will not cause injury or
damage. Leave a 6” gap between the T&P valve pipe termination and the drain or closest obstruction. Do not run the
CAUTION
If an expansion tank is used, do not put any valves between the expansion tank and Indirect Water
Heater inlet.
WARNING
Do not put any valves between the relief valve and the tank.
Do not reduce discharge pipe size.
Do not pipe the relief valve to a point where it could be exposed to freezing temperatures or become
plugged by debris.