DRESSER RB 4700 Manuel D'instructions page 30

Resetting of the shut-off valve with lever
reset (type SSV 8600)
– close the downstream stop valve
– slowly operate the resetting lever 27 clockwise until
the internal by-pass is open 26:
with this operation pressure fills the outlet cham ber 12,
the control chamber 19 and the down stream pipe,
checking on the manometer in stalled on the pipeline
Shut-off valve calibration
The shut-off valve is usually supplied with calibra tion
values according to the order. Should be nec essary to
modify the calibration value, it must be considered
that the modification can be effected only within the
calibration range of the spring in stalled, otherwise it is
necessary to substitute it with a suitable spring to be
selected referring to the provided tables.
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– when the pressure indicated on the manometer is
stabilised, continue to move the lever 27 in
order to permit the connection of the control lever 24;
at this point the lever will remain stable on the opening
position.
After these operations, the shut-off valve is into
operation and it is possible to proceed slowly with the
opening of the downstream valve.
When the installed spring is appropriate to obtain the
required pressure, proceed as follows:
– over-pressure shut-off operation:
rotate in a clockwise direction the external screwing ring
increases the calibration value or in an anti clockwise
direction to reduce it.
– low-pressure shut-off operation:
rotate in a clockwise direction the central screwing ring
to increase the calibration value or in an anti clockwise
direction to reduce it.