P R E S S U R E & T E M P E R AT U R E R E L I E F
PIPEWORK
The safety relief valves should be installed
to discharge in accordance with G3 of the
Approved Document of the Building Regulations
and should be piped to where it is visible, but
will not cause danger to persons or damage to
materials.
The discharge pipework should be of metal
and from the tundish should fall vertically for at
least 300mm, and then continue by continuous
fall to a visible safe termination. The discharge
termination point should be below a fixed
grating and above the water seal of a trapped
gully or other permissible terminations as in G3
of the Approved Document.
Discharges should be visible at either the
tundish or the termination.
SAFETY
The safety devices supplied or fitted on an
Xstream are selected for their suitability for the
temperatures and pressures involved. They
must not be changed or removed and it is
essential that replacements must be supplied or
approved by Gledhill Building Products Limited.
This includes the immersion heaters, which must
incorporate energy cut-out, and are available
to approved installers from Gledhill Building
Products Limited, Sycamore Estate, Squires Gate,
Blackpool (Telephone 01253 474402).
COMBINATION INLET GROUP
Combines elements 1, 2 and 3 below.
1.
Pressure Reducing Valve
- This must be fixed
near the cylinder. The cold water supply
terminal fittings in the property should
be taken from the cold water tapping of
this valve to ensure balanced hot and cold
pressures. This valve is factory set to ensure
the correct operating pressure for the
Xstream.
2.
Non Return Valve
- This is integral with the
pressure reducing valve to prevent backflow
of hot water towards cold water draw off
points.
3.
Cold Water Expansion Relief Valve
- This safety
device is preset at the factory and will relieve
excess cold water pressure resulting from a
fault condition.
Typical Discharge Pipe Arrangement
15 mm
discharge
pipe
Expansion
relief
valve
500 mm max.
P & T
Relief
Valve
300 mm
min.
22 mm metal pipe
with continuous fall
up to 9m equivalent
length.
NOTE: Each elbow is
equivalent to one
metre length.
Discharge below
fixed grating
Fixed
Grating
Trapped gully
Locations to be avoided when siting a discharge
pipe at high level:
1.
The discharge pipe should not be located
above a pedestrian area, or above a window,
door, ventilator etc.
2.
Subsequent freezing of the discharge
should not create a hazard to persons
about the building.
3.
The adjacent structure should be impervious
to water at 80ºC.
x= dia. of discharge
pipe
Alternative Discharge Arrangement (High Level)
Page 10
INSTALLATION