20
Dival SQD-1 - MT 234-E - 02-2020
EN
TROUBLE-SHOOTING
6.1
SQD-1 Pressure regulator (fig.35 - 36 - 37 - 38)
PROBLEM
POSSIBLE CAUSES
REMEDY
No tightness at Q=0
Valve seat [2] damaged
Replace
Obturator [211] damaged
Replace
O-ring [202] damaged
Replace
O-ring [208] damaged
Replace
O-ring [210] damaged
Replace
O-ring [209] damaged
Replace
Diaphragm [206] damaged
Replace
Dirt or foreign bodies in the seal area
Clean
Pumping
Anomalous friction of the rod-obturator
Clean and, if necessary, replace
sealing and/or guide elements
Antipumping valves blockage
Clean and replace if necessary
Reduced downstream volumes
Increase volume
Increase Pd with Q>0
Diaphragm [322] breakage
Replace
Diaphragm [206] breakage
Replace
Tab. 5
6.2
SLAM-SHUTH LA/… (fig. 35 - 38)
PROBLEM
POSSIBLE CAUSES
REMEDY
Slam-shut obturator does not
close
Control head diaphragm [21] ruptured
Change the diaphragm
Leakage from slam-shut
obturator
Obturator gasket [27] deteriorated
Change the gasket
O-ring [166] worn
Change
Obturator seat [2] eroded or pitted
Change the seat
Incorrect intervention pressure
Wrong setting of max and/or minimum
spring
Make the setting again using the
rings [12] and/or [13]
Friction in lever systems
Change
Rearming not
possible
Persistence of the cause which led to pres
-
sure increase or decrease downstream
Decrease or decrease the down
-
stream pressure
Lever systems broken or chipped
Change
Tab. 6
N.B. If the slam-shut has intervened, close the inlet and outlet valve (V1 and V2) in the line and discharge the pressure
before carrying out any operation.
Eliminate the causes which gave rise to intervention before reactivating it. In the event of operating problems
when personnel qualified for a specific operation are not available, call the service centre nearest to you.
For further information contact our SATRI service centre at our Arcugnano (Vicenza) works
