DRESSER RB 4700 Inbetriebnahmeanleitung Seite 33

Resetting of the shut-off valve with lever reset (ty-
pe 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 chamber
12, the control chamber 19 and the downstream pipe,
checking on the manometer installed on the pipeline
Shut-off valve calibration
The shut-off valve is usually supplied with calibration
values according to the order Should be necessary to
modify the calibration value, it must be considered that
the modification can be effected only within the calibra-
tion range of the spring installed, otherwise it is neces-
sary to substitute it with a suitable spring to be selected
referring to the provided tables
– 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 po-
sition
After these operations, the shut-off valve is into opera-
tion and it is possible to proceed slowly with the open-
ing 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 anticlockwise di-
rection 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 anticlockwise
direction to reduce it
33