Samson 46-7 Mounting And Operating Instructions page 37

Table 7: Troubleshooting
Malfunction
Flow rate or
differential pressure
exceeds adjusted set
point
Flow or differential
pressure set point not
reached
Flow or differential
pressure set point not
reached
EB 3131 EN
Possible reasons
Insufficient pressure pulses on the oper-
ating diaphragm.
Foreign particles blocking the plug
Seat and plug are worn or leak.
Valve too large for control task (flow
rate) or too small (differential pressure)
Defective operating diaphragm
Seat and plug are worn or leak.
A safety device (e.g. STL or STM) has
been triggered.
Regulator installed against the flow.
Regulator or K /C coefficient too
VS V
small
Incorrect set point range selected.
Safety device, e.g. pressure limiter, has
been triggered.
Plant differential pressure Δp too low.
Foreign particles blocking the plug
Control line blocked
Strainer blocked.
Recommended action
Î Clean the control line and screw fittings.
Î Remove foreign particles.
Î Replace damaged parts.
Î Contact SAMSON's After-sales Service.
Î Replace the damaged seat and plug.
Î Contact SAMSON's After-sales Service.
Î Check the sizing.
Î Change K /C coefficient, if necessary or in-
VS V
stall a different sized regulator.
Î Contact SAMSON's After-sales Service.
Î Replace damaged diaphragm.
Î Clean the seat and plug.
Î Replace the damaged seat and plug.
Î Contact SAMSON's After-sales Service.
Î Check plant. Unlock safety device (where nec-
essary).
Î Install the regulator so that the direction of flow
matches the direction indicated by the arrow on
the body.
Î Check the sizing.
Î Change K /C coefficient, if necessary or in-
VS V
stall a different sized regulator.
Î Contact SAMSON's After-sales Service.
Î Check set point range
Î Contact SAMSON's After-sales Service.
Î Check plant. If necessary, unlock safety device.
Î Compare differential pressure in the plant with
the plant's drag.
Differential pressure across the plant:
.
∆p = ∆p + (V/K
min restriction
Î Remove foreign particles.
Î Replace damaged parts.
Î Contact SAMSON's After-sales Service.
Î Clean the control line and screw fittings.
Î Clean the strainer.
Malfunctions
)²
VS
37