Samson series 43, Монтаж и эксплуатация

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14 EB 2172 EN
Customer inquiries
Table 2: Troubleshooting
Type 43-5 and Type 43-7
Possible reasons Recommended action
Temperature at the sensor exceeds the set point
Leak at seat and plug Remove valve from the pipeline and clean seat and plug. Renew plug,
if necessary. If this is not possible, return regulator to SAMSON for re-
pair.
Size (DN or G) of the valve is much too
large for the control task.
Recalculate K
VS
and select a smaller valve.
Sensor installed in the wrong location. The entire length of the temperature sensor must be immersed in the
process medium and where idle times or heat buildup cannot occur.
Change mounting position accordingly.
A safety device (e.g. STL or STM) has been
triggered.
Check plant. Unlock safety device.
Thermostat defective Replace thermostat (read specifications on the nameplate).
Temperature at the sensor does not reach the set point
Size (DN or G) of the valve is much too
small for the control task.
Recalculate K
VS
and select a larger valve.
Insufficient heating energy available Draw up an energy balance.
Strainer blocked Drain and clean filter of the strainer.
The valve is not installed in the direction
indicated by the arrow.
Install the valve in such a way that the flow of direction corresponds
with the direction indicated by the arrow on the valve body.
Control loop hunts · Very long dead time/sluggish control response
Size (DN or G) of the valve is much too
large for the control task.
Recalculate K
VS
and select a smaller valve.
Time constant is too large for the control
loop.
Fill the thermowell with thermal paste, remove thermowell or use sen-
sor with smaller time constant.
Sensor installed in the wrong location. The temperature sensor may be installed too far from the area where
the temperature to be controlled arises. Locate the sensor closer to heat
exchanger.
The valve is not installed in the direction
indicated by the arrow.
Install the valve in such a way that the flow of direction corresponds
with the direction indicated by the arrow on the valve body.