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COMMISSIONING 5
COMMISSIONING 5
COMMISSIONING 5
COMMISSIONING 5
COMMISSIONING 5
5-2
Handing Over
Complete the Guarantee Form, the top sheet of this MUST be sent to GAH (HEATING
PRODUCTS) LIMITED. Complete the Benchmark Logbook.
The Installer should re-check the system and ensure it is completely satisfactory before
demonstrating to the householder. The householder should be aware of the following:-
1. How to set the temperature of the tap hot water.
2. The function of the Pressure Relief Valve and Combination Valve and that over
pressure will cause steam and scalding water to be emitted from the discharge pipe.
3. The Tundish is supplied as a visual identification for over pressure.
4. The procedure to follow in the event of over pressure. Refer to 2-5.
This manual and supplements must be left with the householder together with a copy of
the completed Guarantee Form.
5-1.1 Accumulator Pressure
Accumulators are supplied by GAH with a preset air charge of 2 Bar (28/30psi). The
Combination Valve supplied with the Dualstream system has an integral pressure
reducing valve fixed at 3.5 Bar. Therefore there is a pressure differential of 1.5 bar
between the system pressure and the air charge of the Accumulator.
When the incoming mains pressure is less than 3.5 Bar the pressure differential will be
higher than 1.5 Bar and the Accumulator will not fill sufficiently, therefore it may be
necessary to lower the Accumulator air charge pressure.
The procedure for changing the Accumulator pressure is given below, this can be done
before the system has been filled. It may be done after the system has been filled and
tested, providing the incoming main has been turned OFF and the water drained from the
Accumulator. Failure to do this may result in false pressure reading and damage to the
butyl diaphragm.
If mains pressure is 3.5 Bar or above changing the Accumulator charge pressure will not
be necessary.
Adjusting Air Pressure
1. Record mains pressure.
2. Turn main supply OFF.
3. Turn on cold outlets to empty Accumulator.
4. Remove black cap from top of Accumulator check/confirm Accumulator pressure
with pressure gauge.
5. Lower air charge so that is 1 to 1.5 Bar below mains pressure.
Minimum Accumulator pressure is 0.5 bar to 0.8 Bar.
CAUTION
The main supply must be turned
OFF and water drained from the
Accumulator before lowering the
charge pressure, failure to do so
could result in damage to the
diaphragm.
AIR CHARGE VALVE - SCHRADER
BUTYL DIAPHRAM
Fig. 5-1a Accumulator
Also refer to 4-2.5 and 4-5.
If in doubt consult GAH Heating Products.
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