Pressure Reducing Valve - Hyco Speedflow SF10L Fitting & User Instructions

Hyco Manufacturing Ltd Water Heating Accessory kit SF2

Pressure reducing Valve

A. Contents
This kit contains:
•
1 expansion vessel
•
1 pressure reducing valve
B. Compatibility
To be used in conjunction with Hyco Speedflow 10L and 15L unvented (mains pressure) water heaters.
C. When this kit is required
This kit is required if there is a risk that mains incoming water pressure may exceed 4.2 bar. Please
note water pressure fluctuates from place to place and from time to time. It is usually highest at night
when demand for water by the public is lowest.
In most instances water pressure is below 4.2 bar and this kit is not required. If there is any doubt, it is
strongly recommended that the pressure is measured with an appropriate meter.
If the incoming water pressure is too high and this pressure reducing kit is not fitted, the pressure relief
valve (supplied with the heater) should open and discharge water constantly. This is a clear indication
that kit SF2 is required.
The pressure reducing valve must be fitted so that water flows in the direction of the arrow. Water will
not flow in the reverse direction. The valve works by reducing the pressure at the outlet side to approx
3 bar, regardless of the pressure on the inlet side.
The expansion vessel must be fitted downstream of the pressure reducing valve and is necessary to
accommodate the expansion of water as it is heated, as the pressure reducing valve prevents the usual
expansion through the pipework.
If there is a cold water draw off located down stream of the pressure reducing valve, fit a check valve
(not supplied) in the position shown.
D. Installation
Install as shown below:
expansion
vessel
expansion relief valve
hot
cold
to drain
IMPORTANT:ALWAYS FIT THE EXPANSION RELIEF VALVE SUPPLIED WITH THE
HEATER
E. Helpline call 01977 517555 9-5 Mon-Fri for technical assistance
F:my documents\SF2INSTALL.DOC
pressure
reducing
nearest cold water valve
service valve
draw off
check valve
cold water supply