20
4 GV 76 en
11.6
Spray water pipe
Reliable operation of steam condition requires a proper
installation between the AS valve and the spray water con-
trol valve. Spray water piping must ensure continuous and
immediate supply of water and it should not get empty.
The piping coming from the spray water control
valve to the AS valve shall be arranged below the
level of the spray pipe.
The distance between the spray water control valve
and the spray pipe should be minimized to less than
5 meters.
11.7
Drains
Condensate or non evaporated spray water in the valve or
steam piping is very risky, it can cause erosion in piping and
the valve, it causes vibration and water hammer and it can
disturb temperature measurement causing problems in
control.
Upstream drains are necessary to protect the AS valve. The
drain connections shall be at the lowest point and nearest
to the AS valve. Slopes shall be always arranged so that
water flows towards the drain.
Metso´s
guideline value for a standard drain connection
upstream is a G ½” pipe thread.
