Maintenance · Troubleshooting - Samson 42-37 Mounting And Operating Instructions

Maintenance · Troubleshooting
5 Maintenance · Troubleshooting
The regulators are maintenance free. Nevertheless, they are subject to natural wear, particu-
larly at the seat, plug and operating diaphragm. Depending on the operating conditions, the
regulator needs to be checked at regular intervals to avoid possible malfunctions. Details on
faults and the recommended action can be found in the table below.
Table 2 · Troubleshooting
Malfunction Possible reasons
Seat and plug untight
Flow rate or
Operating diaphragm
differential
defective
pressure
exceeds its
Control line blocked
set point
Valve too large for flow
control or too small for
differential pressure control
Seat and plug untight
Wrong set point range
selected
Safety equipment, e.g.
Flow rate or
pressure limiter, has been
differential
triggered
pressure set
point is not
reached
Insufficient pressure drop
across the plant
Strainer blocked
Direction of flow, valve
incorrectly installed
Valve too large for the
control task at hand
Control loop
Restriction (or needle valve)
hunts
is missing in a control line to
dampen pulsation
18
EB 3017 EN
Recommended action
Remove valve from pipeline. Clean seat and plug.
Replace plug, if necessary. Otherwise send the regulator
to SAMSON for repair.
Replace diaphragm or send the regulator to SAMSON
for repair.
Remove control line and clean it.
Recalculate K coefficient and contact SAMSON for
VS
further action.
Remove valve from pipeline. Clean seat and plug.
Replace plug, if necessary. Otherwise send the regulator
to SAMSON for repair.
Check set point range and contact SAMSON for further
action.
Check plant and unlock safety equipment.
Compare existing differential pressure in the plant with
the plant's drag.
Differential pressure across the plant Δp
.
Δp
+ (V K / )².
VS
restriction
Drain and clean filter of the strainer
Install the valve so that the direction of flow is the same
as indicated by the arrow.
Recalculate K coefficient. Contact SAMSON.
VS
Check restriction in the connection to chamber D
(Type 42-37) or chamber C (Type 42-39). If necessary,
install a needle valve in the control line and start to close
it until the control loop becomes stable.
Caution! Do not completely close needle valves.
=
min