METHOD FOR DETECTING AN OPERATING CONDITION ON A VALVE ASSEMBLY AND IMPLEMENTATION THEREOF

• US 20150285397A1
• Filed: 10/02/2014
• Published: 10/08/2015
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: Dresser, LLC (GE Aerospace)
• Original Assignee: Lnc Dresser
• Inventors: Prescott, Robert Claude, Shriver, Justin Scott, Wheeler, Frederick Wilson
• Granted Patent: US 9,719,610 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: F16K 37/0083 by measuring valve parameters
• CPC Class Codes: Y10T 137/8225 Position or extent of motion indicator

Abstract

A method to detect cycling of components that result from use of a tight shut-off mode on a valve assembly. Embodiments of the method use operating data from the valve assembly. This operating data includes data that reflects a position for the closure member relative to the seat. This position often corresponds with a measured position of one or more components (e.g., the valve stem) on the valve assembly. In one embodiment, the method includes steps for comparing the measured position to a boundary criteria that defines one or more boundary values proximate, and often equal to, the threshold levels of the tight shut-off mode. The method can also includes steps for identifying patterns in the data that indicate that the closure member is cycling from its closed position to a second position due to tight shut-off mode.

Claims

1. A method for detecting cycling of a closure member relative to a seat on a valve assembly, said method comprising:

receiving an input with data in a pattern that reflects movement of the closure member;

comparing the data to a boundary criteria, the boundary criteria defining a first boundary value and a second boundary value separated by a boundary interval, wherein each of the first boundary value and the second boundary value is proximate, but larger than, a value for a closed position at which the closure member is in contact with the seat;

incrementing a cycle count each time the pattern changes from a first value to a second value that is separated from the first value by at least the boundary interval; and

generating an output that reflects the cycle count.

2. The method of claim 1, further comprising:

reducing the cycle count by one-half; and

comparing the cycle count to a pattern value that defines a number of closure member cycles, wherein the output reflects a relationship between the cycle count and the pattern value.

3. The method of claim 1, further comprising:

determining a value for a minimum position that corresponds with a smallest value in the pattern; and

assigning the first boundary value and the second boundary value relative to this minimum position.

4. The method of claim 3, further comprising:

applying a factor to the minimum position to arrive at the first boundary value and the second boundary value, wherein the factor includes a first factor and a second factor for use with, respectively, the first boundary value and the second boundary value, and wherein the first factor is different from the second factor.

5. The method of claim 4, wherein the first boundary value is calculated in accordance with,

BL₁=M_T+R₁,

wherein BL₁ is the first boundary value, M_T is the value for the minimum position, and R₁ is the first factor that is selected to space the first boundary value from the minimum position.

6. The method of claim 4, wherein the second boundary value is calculated in accordance with,

BL₂=M_T+R₂,

wherein BL₂ is the second boundary value, M_T is the value for the minimum position, and R₂ is the second factor.

7. The method of claim 1, wherein the boundary interval is configured so that the first boundary value equals the second boundary value.

8. A valve assembly, comprising:

an actuator;

a valve stem coupled with the actuator;

a valve coupled with the valve stem, the valve comprising a closure member and a seat, wherein the closure member is configured to move relative to the seat; and

a valve positioner coupled with the valve assembly, the valve positioner comprising a processor with access to a memory that has one or more executable instructions stored thereon, the executable instructions comprising one or more instructions for,

receiving an input with data in a pattern that reflects movement of the closure member,

comparing the data to a boundary criteria, the boundary criteria defining a first boundary value and a second boundary value separated from one another by a boundary interval, wherein each of the first boundary value and the second boundary value is proximate, but larger than, a value for a closed position at which the closure member is in contact with the seat, and

incrementing a cycle count each time the pattern changes from a first value to a second value that is separated from the first value by at least the boundary interval; and

generating an output that reflects the cycle count.

9. The valve assembly of claim 8, wherein the executable instructions include instructions for:

reducing the cycle count by one-half; and

comparing the cycle count to a pattern value that defines a number of closure member cycles, wherein the output reflects a relationship between the cycle count and the pattern value.

10. The valve assembly of claim 8, wherein the executable instructions include instructions for:

determining a value for a minimum position that corresponds with a smallest value in the pattern; and

assigning the first boundary value and the second boundary value using this minimum position.

11. The valve assembly of claim 10, wherein the executable instructions include instructions for:

applying a factor to the minimum position to arrive at the first boundary value and the second boundary value, wherein the factor includes a first factor and a second factor for use with, respectively, the first boundary value and the second boundary value, and wherein the first factor is different from the second factor.

12. The valve assembly of claim 11, wherein the executable instructions include instructions for:

assigning the first boundary value in accordance with,

BL₁=M_T+R₁,

wherein BL₁ is the first boundary value, M_T is the value for the minimum position, and R₁ is the first factor that is selected to space the first boundary value from the minimum position.

13. The valve assembly of claim 11, wherein the executable instructions include instructions for:

assigning the second boundary value in accordance with,

BL₂=M_T+R₂,

wherein BL₂ is the second boundary value, M_T is the value for the minimum position, and R₂ is the second factor.

14. The valve assembly of claim 8, wherein the boundary interval is configured so that the first boundary value equals the second boundary value.

15. A valve positioner for use on a valve assembly having a closure member that moves relative to a seat, the valve positioner comprising:

a processor;

a memory coupled with the processor; and

one or more executable instructions stored in the memory and configured to be executed by the processor, the executable instruction comprising one or more instruction for,

receiving an input with data in a pattern that reflects movement of the closure member,

comparing the data to a boundary criteria, the boundary criteria defining a first boundary value and a second boundary value separated from one another by a boundary interval, wherein each of the first boundary value and the second boundary value is proximate, but larger than, a value for a closed position at which the closure member is in contact with the seat, and

incrementing a cycle count each time the pattern changes from a first value to a second value that is separated from the first value by at least the boundary interval; and

generating an output that reflects the cycle count.

16. The valve positioner of claim 15, wherein the boundary interval is configured so that the first boundary value equals the second boundary value.

17. The valve positioner of claim 15, wherein the executable instructions include instructions for:

reducing the cycle count by one-half; and

comparing the cycle count to a pattern value that defines a number of closure member cycles, wherein the output reflects a relationship between the cycle count and the pattern value.

18. The valve positioner of claim 17, wherein the executable instructions include instructions for:

determining a value for a minimum position that corresponds with a smallest value in the pattern; and

assigning the first boundary value and the second boundary value using the minimum position.

19. The valve positioner of claim 18, further comprising:

applying a factor to the minimum position to arrive at the first boundary value and the second boundary value, wherein the factor includes a first factor and a second factor for use with, respectively, the first boundary value and the second boundary value, and wherein the first factor is different from the second factor

20. The valve positioner of claim 19, wherein the executable instructions include instructions for:

assigning the first boundary value in accordance with,

BL₁=M_T+R₁,

wherein BL₁ is the first boundary value, M_T is the value for the minimum position, and R₁ is the first factor that is selected to space the first boundary value from the minimum position; and

assigning the second boundary value in accordance with,

BL₂=M_T+R₂,

wherein BL₂ is the second boundary value, M_T is the value for the minimum position, and R₂ is the second factor.