Samson 2479 Mounting And Operating Instructions page 50

Malfunctions
Malfunction
Temperature at the
sensor or the flow rate
does not reach the set
point.
Slow control re-
sponse
Jerky control re-
sponse
Leakage at the actua-
tor
8-2
Possible reasons
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
Control thermostat defective
Insufficient heating energy available
Sensor installed in the wrong location.
Sensor installed incorrectly.
Restriction in the screw joint of the ac-
tuator dirty or too small
Dirt in the control line
Increased friction, e.g. due to foreign
particles between seat and plug
Defective operating diaphragm
Recommended action
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
.
+ (V/K )²
striction VS
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 the control thermostat.
Î Draw up an energy balance.
Î Change the mounting position.
Î Immerse the temperature sensor with its entire
immersion depth in the process medium.
Î Avoid an installation site where idle times or
heat buildup can occur.
Î Clean screw joint or install larger screw joint.
Î Clean the control line.
Î Remove foreign particles.
Î Replace damaged parts.
Î Contact SAMSON's After-sales Service.
Î Replace damaged diaphragm.
= ∆p
min re-
EB 3132-3 EN