Methods and apparatus for estimating useful life of a seal

Patent metadata

Field	Value
Publication number	US-9062771-B2
Application number	US-201213371263-A
Country	US
Kind code	B2
Filing date	Feb 10, 2012
Priority date	Feb 10, 2012
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

Methods and apparatus for estimating useful life of a seal in a process control device are disclosed. An example method includes establishing a plurality of travel ranges of a stem or shaft of a process control device. Each travel range corresponds to different values corresponding to stresses experienced by the seal of the process control device during an operational cycle. The example further includes determining a count of operational cycles associated with each of the travel ranges and estimating a total amount of useful life of the seal consumed based on the counts.

First claim

What is claimed is:

1. A method of estimating useful life of a seal in a process control device, comprising:
determining, via a processor, a plurality of operational cycles of a stem or shaft of the process control device;
determining, via the processor, a value corresponding to a stress experienced between the seal and a plug for each of the operational cycles;
estimating, via the processor, a total amount of useful life of the seal consumed based on each of the values; and
estimating a remaining useful life of the seal based on the estimated total amount of useful life of the seal consumed, wherein estimating the remaining useful life of the seal comprises determining a frequency of the operational cycles and calculating the remaining useful life of the seal based on the total amount of the useful life of the seal consumed and the frequency of the operational cycles.

2. The method of claim 1 , wherein the value corresponding to the stress experienced by the seal is corresponds to a distance traveled by the stem or shaft.

3. The method of claim 1 , further comprising sending an alert message prior to when the estimated total amount of useful life of the seal consumed is one hundred percent.

4. The method of claim 1 ,
further comprising associating each of the values with one of a plurality of travel ranges of the stem or shaft.

5. A method of estimating useful life of a seal in a process control device, comprising:
determining, via a processor, a plurality of operational cycles of a stem or shaft of the process control device;
determining, via the processor, a value corresponding to a stress experienced between the seal and a plug for each of the operational cycles;
estimating, via the processor, a total amount of useful life of the seal consumed based on each of the values, wherein estimating the total amount of useful life of the seal consumed comprises:
establishing a plurality of travel ranges of the stem or shaft, each travel range corresponding to different values corresponding to stresses experienced by the seal;
associating each of the values with only one of the travel ranges;
determining a count of values associated with each of the travel ranges;
calculating a ratio for each count and the associated travel range; and
summing the ratios to determine a value indicative of the total amount of useful life of the seal consumed.

6. The method of claim 5 , wherein calculating the ratios comprises dividing each count by a predetermined estimated cycle life value corresponding to the travel range associated with the count.

7. The method of claim 6 , further comprising determining the predetermined estimated cycle life values by testing a plurality of other process control devices similar or identical to the process control device.

8. The method of claim 5 , wherein the values corresponding to the stresses experienced by the seal correspond to respective distances traveled by the stem or shaft.

9. A method of estimating useful life of a seal in a process control device, comprising:
determining, via a processor, a plurality of operational cycles of a stem or shaft of the process control device;
determining, via a processor, a value corresponding to a stress experienced between the seal and a plug for each of the operational cycles, wherein the value corresponding to the stress experienced by the seal is a position of the stem or shaft during each of the operational cycles farthest from a position of the stem or shaft where the seal experiences about zero stress; and
estimating, via a processor, a total amount of useful life of the seal consumed based on each of the values.

10. The method of claim 9 , further comprising estimating a remaining useful life of the seal based on the estimated total amount of useful life of the seal consumed.

11. The method of claim 9 , further comprising sending an alert message prior to when the estimated total amount of useful life of the seal consumed is one hundred percent.

12. A method of estimating useful life of a seal in a process control device, comprising:
establishing, via a processor, a plurality of travel ranges of a stem or shaft of the process control device, each travel range corresponding to different values corresponding to stresses experienced by the seal during an operational cycle;
determining, via the processor, a count of operational cycles associated with each of the travel ranges, wherein determining the count of operational cycles associated with each of the travel ranges comprises:
determining a plurality of operational cycles;
determining, via the processor, a value corresponding to a stress experienced between the seal and a plug of the process control device during each operational cycle; and
associating each of the values with only one of the travel ranges;

estimating, via the processor, a total amount of useful life of the seal consumed based on the counts, wherein estimating the total amount of useful life of the seal consumed comprises:
calculating a ratio for each count and associated travel range; and
summing the ratios to determine a value indicative of the total amount of useful life of the seal consumed.

13. The method of claim 12 , wherein calculating the ratios comprises dividing each count by a predetermined estimated cycle life value corresponding to the travel range associated with the count.

14. The method of claim 12 , further comprising estimating a remaining useful life of the seal based on the estimated total amount of useful life of the seal consumed.

15. The method of claim 14 , wherein estimating the remaining useful life of the seal comprises determining a frequency of the operational cycles and calculating the remaining useful life of the seal based on the total amount of the useful life of the seal consumed and the frequency.

16. The method of claim 12 , wherein the values corresponding to the stresses experienced by the seal are correspond to distances traveled by the stem or shaft.

17. A method of estimating useful life of a seal in a process control device, comprising:
establishing a plurality of travel ranges of a stem or shaft of the process control device, each travel range corresponding to different values corresponding to stresses experienced by the seal during an operational cycle, wherein the values corresponding to the stresses experienced by the seal correspond to positions of the stem or shaft during the operational cycles farthest from a position of the stem or shaft where the seal experiences about zero stress;
determining, via a processor, a count of operational cycles associated with each of the travel ranges; and
estimating, via the processor, a total amount of useful life of the seal consumed based on the counts.

18. The method of claim 17 , wherein the values corresponding to the stresses experienced by the seal correspond to distances traveled by the stem or shaft.

19. An article of manufacture storing machine readable instructions which, when executed, cause a machine to:
determine a plurality of operational cycles of a stem or shaft of a process control device;
determine a value corresponding to a stress experienced between a seal and a plug of the process control device for each of the operational cycles;
estimate an amount of remaining useful life of the seal based on each of the values and an estimated total life;
establish a plurality of travel ranges of the stem or shaft, each travel range corresponding to different values corresponding to stresses experienced by the seal;
associate each

Assignees

• Anderson Shawn William
• Fisher Controls Int

Inventors

• Anderson Shawn William

Classifications

• G05B23/0283

  Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] (preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06) · CPC title

• F16K41/10

  with diaphragm, e.g. shaped as bellows or tube · CPC title

• G01N3/32

  by applying repeated or pulsating forces · CPC title

• F16K37/0083

  by measuring valve parameters · CPC title

• F16J15/064 Primary

  the packing combining the sealing function with other functions · CPC title