System for testing a valve

1. A portable system ( 100 ) for testing a pressure safety valve ( 3 ) in a process plant, where the pressure safety valve ( 3 ) is connected to an upstream isolation valve ( 2 ), the portable system ( 100 ) comprising:

an upstream supply line ( 101 ) with an upstream connector ( 102 ) for connecting to a drain port at an upstream end of the pressure safety valve ( 3 );

an actuator ( 121 ) for applying a pressure to the upstream supply line ( 101 );

an upstream sensor ( 122 ) on the upstream supply line ( 101 ); and

a portable computer ( 110 ) capable of running a controller ( 120 ),

wherein the controller ( 120 ) is adapted to receive measurements from the upstream sensor ( 122 ), store the measurements in non-volatile memory, and send control signals to the actuator ( 123 ),

wherein the upstream sensor ( 122 ) is a pressure sensor or flow sensor and the controller is configured to receive one or more measurements from the upstream sensor ( 122 ) and determine a leakage through the upstream isolation valve ( 2 ) and subsequently instruct the actuator to apply an increasing pressure through the drain port when the pressure safety valve ( 3 ) is closed until the pressure safety valve ( 3 ) opens, measure the increasing pressure at a point at which the pressure safety valve ( 3 ) opens with the upstream sensor ( 122 ), and determine an activation pressure of the pressure safety valve ( 3 ) taking into account the leakage through the upstream isolation valve ( 2 ).

2. The portable system ( 100 ) according to claim 1 further comprising:

a downstream return line ( 103 ) with a downstream connector ( 104 ) for connecting to a downstream end of the pressure safety valve ( 3 ); and

a downstream sensor ( 124 ) on the downstream return line ( 103 ); wherein the actuator is configured to apply a pressure difference between the upstream supply line ( 101 ) and the downstream return line ( 103 ) and the controller ( 120 ) is adapted to receive measurements from the upstream sensor ( 122 ) and the downstream sensor ( 124 ),

wherein the downstream connector ( 104 ) is configured to connect to the drain port such that the pressure safety valve ( 3 ) remains directly connected to a downstream isolation valve ( 4 ) during testing.

3. The portable system ( 100 ) according to claim 2 wherein the downstream sensor ( 124 ) is a pressure sensor or flow sensor and the controller is configured to receive one or more measurements from the downstream sensor ( 124 ) and determine a leakage through a downstream isolation valve ( 4 ).

4. The system ( 100 ) according to claim 3 wherein the controller ( 120 ) is configured to determine the leakage through the upstream isolation valve ( 2 ) and/or the leakage through the downstream isolation valve ( 4 ) by receiving a measurement from the upstream sensor ( 122 ) and receiving a measurement from the downstream sensor ( 124 ) while the pressure safety valve ( 3 ) is open and calculate a difference between the measurement from the upstream sensor ( 122 ) and the measurement from the downstream sensor ( 124 ).

5. The portable system ( 100 ) according to claim 3 wherein the controller ( 120 ) is configured to control the actuator ( 121 ) to apply a pressure to the upstream connector ( 102 ) or a downstream connector ( 104 ) while the pressure safety valve is closed; and receive a measurement from the upstream sensor ( 122 ) or the downstream sensor ( 124 ) to determine the leakage through the upstream isolation valve ( 2 ) or the leakage through the downstream isolation valve ( 4 ).

6. The portable system ( 100 ) according to claim 2 wherein the actuator ( 121 ) is configured to provide pressurised nitrogen such that the pressure difference between the upstream supply line ( 101 ) and the downstream return line ( 103 ) is provided by providing pressurised nitrogen through one or both of the upstream connector ( 102 ) and the downstream connector ( 104 ) to the corresponding drain port.

7. The portable system ( 100 ) according to claim 2 wherein the upstream supply line ( 101 ) and the downstream return line ( 103 ) comprise flexible hoses.

8. The portable system ( 100 ) according to claim 1 , wherein the controller ( 120 ) has a decision function that sends separate control signals depending on the measurements received from the upstream sensor ( 122 ).

9. The portable system ( 100 ) according to claim 1 , wherein the portable computer ( 110 ) further comprises a security system ( 130 ) capable of combining the measurement and identifying information in a data file, computing a hash of the data file, and storing the hash in a hash file.

10. The portable system ( 100 ) according to claim 9 , wherein the security system ( 130 ) has further functions for encrypting a computer file.

11. A method of testing a pressure safety valve ( 3 ) in a process plant, where the pressure safety valve ( 3 ) is connected to an upstream isolation valve ( 2 ) the method comprising:

connecting an upstream supply line ( 101 ) to the upstream to a drain port end of the pressure safety valve ( 3 ) with an upstream connector ( 102 );

applying a pressure to the upstream supply line ( 101 );

determining a leakage through the upstream isolation valve ( 2 );

instructing an actuator to apply an increasing pressure through the drain port when the pressure safety valve ( 3 ) is closed until the pressure safety valve ( 3 ) opens;

measuring the increasing pressure at a point at which the pressure safety valve ( 3 ) opens with an upstream sensor ( 122 ); and

determining an activation pressure of the pressure safety valve ( 3 ) taking into account the leakage through the upstream isolation valve ( 2 ),

characterised in that the upstream connector ( 102 ) is connected to the drain port such that the pressure safety valve ( 3 ) remains fluidically connected to the upstream isolation valve ( 2 ) during testing.

12. The method of claim 11 further comprising:

connecting a downstream return line ( 103 ) to the downstream end of the pressure safety valve ( 3 ) with a downstream connector ( 104 ), and

applying a pressure difference between the upstream supply line ( 101 ) and the downstream return line ( 103 ).

13. The method of claim 12 wherein the downstream connector ( 104 ) is connected to the drain port such that the pressure safety valve ( 3 ) remains directly connected to a downstream isolation valve ( 4 ) during testing.

14. The method of claim 11 wherein the pressure is applied by applying pressurised nitrogen through an upstream and/or downstream drain port.

15. The method of claim 13 further comprising:

closing the upstream isolation valve and/or the downstream isolation valve to isolate the pressure safety valve to be tested before applying a pressure.

16. The method of claim 15 further comprising:

measuring the pressure or flow rate in the upstream supply line ( 101 ) and/or downstream return line ( 103 ); and

determining a leakage through a upstream isolation valve ( 2 ) or a downstream isolation valve ( 4 ).

17. The method of claim 16 further comprising:

measuring the pressure or flow rate in the upstream supply line ( 101 ) and in the downstream supply line ( 103 ) while the pressure safety valve is open; and

determining the leakage through the upstream isolation valve ( 2 ) or the downstream isolation valve ( 4 ) by calculating a difference between the pressure or flow rate in the upstream supply line ( 101 ) and the downstream supply line ( 103 ).

18. The method of claim 16 comprising:

applying the pressure to the upstream supply line ( 101 ) or the downstream return line ( 103 ) while the pressure safety valve is closed;

measuring the pressure or flow rate in the upstream supply line ( 101 ) or the downstream return line ( 103 ); and

determining the leakage through the upstream isolation valve ( 2 ) or the downstream isolation valve ( 4 ) based on the pressure or flow rate.

19. The method of claim 13 , wherein the pressure safety valve is a pressure safety valve, the method further comprising:

applying an increasing pressure through the drain port when the pressure safety valve is closed until the pressure safety valve opens; and

measuring the applied pressure at a point that the pressure safety valve opens.

20. The method of claim 13 further comprising:

applying a constant pressure to an upstream drain port of the pressure safety valve while the pressure safety valve is closed; and

measuring a pressure or flow rate through the downstream return line.