ON/OFF Valves Loop Checks Procedure

We discuss about ON/OFF Valves Loop Checks Procedure. This involves valve loop checks, shutdown valve loop checks, ESD valves loop checks.

ON/OFF Valves Loop Checks Procedure

  1. Valve response time shall be recorded in loop record sheet.

  2. Check and verify the DCS / ESD configuration for applicable points.

  3. If any ESD logic / interlocking are involved in applicable loop to energized solenoid valve, should be prepared ESD points on functional logic and same procedure to be carried out for DCS logic.

  4. If instrument air supply is not available then connect nitrogen cylinder. In big size of valve cases, big volume of nitrogen will be required then in that case on/off valves function test will be executed upon air supply availability.

  5. Apply the command from DCS / field for open and close as applicable.

  6. Verifying the corresponding valves position in DCS and field.

  7. Verify the partial stroke function test of “ZV”.

  8. Verify the valve action on air supply failure.

  9. Check the hand wheel / hand jack manual operation / function as applicable.

  10. Normally On/Off valve loop test should be performed after completion of the external air supply piping works. In some cases when required, loop test can be executed without air.

  11. In case of air piping is not installed and tested then this exception item to be mentioned in the loop test exception log sheet prior to signing the loop folder.

  12. Loop will be initiated only and signed after the clearance of the punch list.