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H2O BOILER
HC SERIES IOM Manual
2.5
Relief Valve piping
A pressure relief valve is supplied as standard equipment. The relief valve is extra protection
against damage that could be caused by excessive water pressure. Either, mal-functioning of
controls, or creation of steam pockets due to water stagnation in some parts of the coils, may cause
such excessive pressure. This latter condition could arise if one or both coils are not properly
purged.
The pressure relief valve should be connected to a suitable water drain. The drain pipe MUST
pitch down from the valve and its internal diameter should not be less than that of the relief valve.
The end of the drain line should not cause any restriction to the water flow, and should be
protected from freezing. There should not be any valve of any type installed between the pressure
relief valve and the end of the drain line. Similarly, there should not be any instrument installed
anywhere along the length of the drain valve, between the relief valve and the end of the drain line.
The relief valve is installed in vertical position and should remain in that position at all times.
2.6
Water Connection
All pre-installation work has been completed at the factory. Two water manifolds (inlet and outlet
headers) are provided with the unit.
Cold-water inlet and hot water outlet connections are clearly marked on the respective manifolds
of the boiler/water heater. The cold water supply line (in one pass applications), or return water (in
closed loop applications) should be connected to the cold water inlet of the unit. The hot water
supply line should be connected to the hot water outlet of the boiler. Both manifolds have 3”
stainless steel flange, ANSI 150 lbs inlet/outlet connections.
For further information on methods of connecting supply and return water piping to boilers/water
heaters consult available installation and piping guides developed according to local plumbing
codes.
Note:
If a water heater is installed in a closed water supply system, such as one
having a backflow preventer in the cold water supply line, means shall be
provided to control thermal expansion. Contact the water supplier or local
plumbing inspector on how to control this situation.
D-VAC Sales Inc. Email: [email protected] Tel: (516) 256-3131 www.dvachvac.com
