Birkett Technical Catalogue - Safety Systems UK Ltd

ACCESSORIES
Packed lever
The design of the packed lever assembly ensures that
leakage does not occur when the valve is open or
when back pressure is present.
Balanced piston
This option is only available on the 7D Series
valves. It is designed to overcome the effects of
variable back pressure.
Open lever design is not available on Safeflo valves.
Gag Screw
Sealing Plug
Test gag
The test gag is used to prevent the
safety valve from lifting. This is
mainly used when carrying out a
hydrostatic test on the system,
during commissioning.
The test gag must never be left in
the valve. The sealing plug should
be fitted at all other times, allowing
the valve to operate freely.
Pressure adjustment: refer to page 47.
Cold differential test pressure: refer to page 47.
Seat tightness/Seat leakage testing: refer to page 49/50.
Minimum pressure setting: B Series, normal attitude 10 Psig.
C Series, normal attitude 15 Psig.
7D Series, normal attitude 5 Psig.
6D Series, normal attitude 740 Psig.
Lower pressures are NOT available by inverting the valve.
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