What makes the valve travel unstable?

a. The setting of the controller is faulty

To do:

1. Check the set value based on the controllers PID parameters
2. Adjust the controllers setting values

Why is the steam blowing?

a. There is a build-up of dirt on the trap valve seat or on the float

To do:

1. Check the trap valve seat and the float
2. Clean or replace

b. The Body is installed tilted

To do:

1. Check the installation conditions
2. Correct the installation

c. The float is deformed

To do:

1. Check the float
2. Replace with a new float (Inspect for water hammer or freezing)

d. There is vibration in the piping

To do:

1. Check the piping conditions
2. Remove the source of the vibration or reinforce the piping supports

Why is the none of the condensate discharged?

a. The primary pressure exceeds the trap valve seat maximum working pressure

To do:

1. Check the primary pressure
2. Change to a suitable pressure

b. Water inside the float

To do:

1. Check the float
2. Replace with a new float

c. Output piping is clogged

To do:

1. Check the output piping
2. Clean or modify the piping

d. The trap valve seat is clogged

To do:

1. Check the trap valve seat
2. Clean or replace with a new trap valve seat

What do I do with a valve leakage?

a. The pressure of the air supply to the positioner is too high

To do:

1. Check the pressure of the air supply and confirm with product specifications

b. The positioners zero point is miscalibrated

To do:

1. Check the actuator air supply pressure (on the positioners pressure gauge) when the operating signal is at 4mA. Check if the pressure on the pressure gauge is elevated (not zero)
2. Adjust the positioners zero point

c. The inlet pressure for the valve is too high

To do:

1. Check the inlet pressure for the valve. Operate at an inlet pressure of 10 bar or less

d. The valve plug or valve seat are off center

To do:

1. Move the valve plug and stem up and down and check to see if it catches
2. Reassemble the valve bonnet section correctly

e. There is a problem with the sealing surfaces of the valve plug and valve seat

To do:

1. Check the valve plug and valve seat
2. Replace with a new valve plug, stem and valve seat

Why is the steam pressure zero?

a. Regulating valve clogged or actuator damaged

To do:

1. Check the filter and/or actuator (RV).
2. Manually open the valve or see if it opens in maintenance mode from the HMI
3. Clean or replace filter

Why is the steam pressure too high/low?

a. Pressure regulating valve (RV) defective

To do:

1. Check that feedback is not clogged.
2. Clean feedback if necessary
3. Check that filter insert is not clogged.
4. Replace filter insert if necessary.
5. Tap valve to see if it has become stuck over time.
6. Readjust valve to maximum then to minimum then to valid setting, to see if function can be restored.
7. If upper steps does not fix it then replace valve.

Why does the valve not travel beyond a certain point?

a. The bellowphragm in the actuator is broken

To do:

1. Check to see if a large amount of air is leaking from the exhaust tap
2. Replace with a new positioner/actuator unit

b. The positioners internal parts are broken (the diaphragm is cracked or damaged)

 To do:

1. Check to see if any unusual noise is coming from the positioner
2. Replace with a new positioner/actuator unit

c. There is insufficient air supply pressure to the positioner

To do:

1. Check the pressure of the air supply to the positioner and refer to the product specifications
2. Adjust the air supply pressure to the positioner according to product specifications

d. Malfunction of the signal system

To do:

1. Check to make sure the controller is emitting a 4 to 20mA signal and that the wires are not disconnected or broken
2. Manually open the valve or see if it opens in maintenance mode from the HMI
3. Repair the signal wiring if necessary

 

What to do when there is no movement at all?

a. Air is not being supplied to the positioner

To do:

1. Make sure that the compressor is operating as it should
2. Make sure that the regulator connected to the positioner inlet is set
3. Initiate the supply of the designated air supply pressure to the positioner according to product specifications

b. The input signal wiring is incorrect connected

To do:

1. Check to make sure the wiring is connected to the correct terminals and that the plus and minus polarity are not reversed
2. Correct the connection

c. The input signal is not being input

To do:

1. Check that 4 – 20mA is being input by the positioner connection terminals
2. Repair the operating signal origin or repair the signal wiring

d. There is water or oil inside the positioner

To do:

1. Check to see if there is water or oil entrained in the supply air
2. Check to see if the humidity at the control valve piping location is too high
3. Replace with a new positioner/actuator unit and improve the quality of the air supply.

Why does the valves open and close too slowly?

a. There is water or oil inside the positioner

To do:

1. Check to see if there is water or oil entrained in the air supply
2. Replace with a new positioner/actuator unit and improve the quality of the air supply

b. The filter regulator is clogged

To do:

1. Check the filter
2. Clean the filter or replace with a new filter