37
Resetting of the shut-off valve with lever reset
(type SSV 8600)
– closethedownstreamstopvalve
– slowlyoperatetheresettinglever27clockwise
untiltheinternalby-passisopen26:
withthisoperationpressurefillstheoutletcham-
ber12,thecontrolchamber19andthedown-
stream pipe, checking on the manometer in-
stalledonthepipeline
– whenthepressureindicatedonthemanometer
isstabilised,continuetomovethelever27in
ordertopermittheconnectionofthecontrol
lever24;atthispointtheleverwillremainstable
ontheopeningposition
After these operations, the shut-off valve is into
operationanditispossibletoproceedslowlywith
theopeningofthedownstreamvalve
Shut-off valve calibration
Theshut-offvalveisusuallysuppliedwithcalibra-
tionvaluesaccordingtotheorderShouldbenec-
essarytomodifythecalibrationvalue,itmustbe
consideredthatthemodificationcanbeeffected
onlywithinthecalibrationrangeofthespringin-
stalled,otherwiseitisnecessarytosubstituteitwith
a suitable spring to be selected referring to the
providedtables
Whentheinstalledspringisappropriatetoobtain
therequiredpressure,proceedasfollows:
– over-pressure shut-off operation:
rotateinaclockwisedirectiontheexternalscrewing
ringincreasesthecalibrationvalueorinananti-
clockwisedirectiontoreduceit
– low-pressure shut-off operation:
rotateinaclockwisedirectionthecentralscrewing
ringtoincreasethecalibrationvalueorinananti-
clockwisedirectiontoreduceit