Remote process seal with improved stability in demanding applications

• US 20050126296A1
• Filed: 12/16/2003
• Published: 06/16/2005
• Est. Priority Date: 12/16/2003
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Granted Patent: US 7,290,452 B2
• Time in Patent Office: Days
• US Class Current: 73/706
• CPC Class Codes: F16J 3/02 Diaphragms
• CPC Class Codes: G01L 19/0046 using isolation membranes G01L13/026 and G01L19/0645 take precedence
• CPC Class Codes: G01L 19/06 Means for preventing overload or deleterious influence of the measured medium on the measuring device or vice versa
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection

Abstract

A remote process seal system is provided. The seal system includes at least one remote process seal assembly coupled to a process pressure transmitter via a coupling filled with an incompressible fluid. The incompressible fluid is contacted by at least one getter to reduce instabilities caused by the release of hydrogen gas accumulating over time. In one aspect, a layer of getter material is deposited or placed within the pressure transducing portion of the remote process seal assembly.

Claims

1. A remote process seal system comprising:

a process pressure transmitter having at least one pressure inlet;

a remote process seal assembly in fluid communication with the at least one pressure inlet of the process pressure transmitter, the remote process seal assembly being adapted to convey a process fluid pressure through a fill fluid to the at least one pressure inlet while isolating the process fluid from the at least one pressure inlet; and

a getter disposed to contact fill fluid within the system.

2. The system of claims 1, wherein the getter is disposed in the remote process seal assembly.

3. The system of claim 2, wherein the getter is disposed proximate a pressure transducing portion of the remote process seal assembly.

4. The system of claim 2, wherein the getter is disposed within a recess in the remote process seal assembly.

5. The system of claim 4, and further comprising a screen mounted over the getter.

6. The system of claim 1, wherein the getter is a material flashed upon a surface of the remote process seal assembly.

7. The system of claim 5, wherein the screen is metallic.

8. The system of claim 1, wherein the getter is polymeric getter.

9. The system of claim 1, wherein the fill fluid is silicone oil.

10. The system of claim 1, wherein the remote seal assembly is constructed from stainless steal.

11. Wherein the system of claim 1, wherein the conductivity of the getter is measured and is a diagnostic indication of the product life of the remote seal assembly.

12. A remote process seal assembly comprising:

an isolation diaphragm welded to a plate member to form a chamber therein; and

a getter disposed within the chamber and adapted to contact an incompressible fill fluid when such fluid is introduced to the remote process seal assembly.

13. The assembly of claim 12, wherein the getter is disposed within a recess in the chamber.

14. The assembly of claim 12, wherein the plate member includes convolutions opposing an interior surface of the isolator diaphragm.

15. The assembly of claim 12, and further comprising a screen disposed between the getter and the isolator diaphragm.

16. The assembly of claim 12, wherein the plate member includes a channel extending under the getter.

18. The method of claim 15, wherein the incompressible fill fluid is oil.

19. The method of claim 18, wherein the oil is a silicone oil.

17. A method of maintaining a fill fluid in a process system, the method comprising:

contacting the incompressible fill fluid with a getter to absorb hydrogen released into the incompressible fill fluid.

20. The method of claim 17, wherein the fill fluid is disposed within a remote process seal system.

21. The method of claim 17, wherein the fill fluid is disposed within a pressure transmitter.