Samson 42-34 Mounting And Operating Instructions page 58

Malfunctions
Malfunction
Flow or differential
pressure set point not
reached
Loud noises
Note
Contact SAMSON's After-sales Service for malfunctions not listed in the table.
The malfunctions listed in section 8.1 are caused by mechanical faults and incorrect regulator
sizing. In the simplest case, the functioning can be restored following the recommended ac-
tion. Special tools may be required to rectify the fault.
Exceptional operating and installation conditions may lead to changed situations that may
affect the control response and lead to malfunctions. For troubleshooting, the conditions, such
as installation, process medium, temperature and pressure conditions, must be taken into ac-
count.
8-2
Possible reasons
Regulator installed against the flow
Plant differential pressure Δp too low
Regulator or K /C coefficient too
VS V
large
Safety device, e.g. pressure limiter, has
been triggered
Incorrect set point range selected
Foreign particles blocking the plug
Control line blocked
Strainer blocked
Defective operating diaphragm
High flow velocity, cavitation
Recommended action
Î Install the regulator so that the direction of flow
matches the direction indicated by the arrow on
the body.
Î Compare differential pressure in the plant with
the plant's drag.

Plant differential pressure
∆p = ∆p
min restriction
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 plant. If necessary, unlock safety device.
Î Check set point range
Î Contact SAMSON's After-sales Service.
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.
Î Replace damaged diaphragm.
Î Check the sizing.
Î Install larger regulator, if necessary.
.
+ (V/K )²
VS
EB 3013 EN