HYDROSTATIC TESTING METHOD

Abstract

The present disclosure provides a method for pressure-testing a pressure vessel, said method comprising using a test fluid which is, or comprises, a halogenated compound selected from the group consisting of tropodegradable halogenated compounds, fluorinated compounds, halogenated ketones, halogenated alkenes and halogenated ethers.

Claims

1. A method for pressure-testing a pressure vessel, said method comprising using a test fluid which comprises a halogenated compound selected from the group consisting of tropodegradable halogenated compounds, fluorinated compounds, halogenated ketones, halogenated alkenes and halogenated ethers.

2. The method of claim 1, wherein said halogenated compound is a tropodegradable halogenated compound.

3. The method of claim 1 wherein said halogenated compound is selected from the group consisting of: (i) fluorinated compounds, (ii) halogenated ketones, (iii) halogenated alkenes, and (iv) halogenated ethers.

4. The method of claim 1, wherein the test fluid consists of one or more of said halogenated compounds.

5. The method of claim 1, wherein the halogenated compound has a boiling point in the range of 30 to 200 C.

6. The method of claim 1, wherein the halogenated compound is a halogenated ketone.

7. The method of claim 1, wherein the halogenated compound is a fluorinated compound.

8. The method of claim 7, wherein the halogenated compound is selected from the group consisting of fluorinated ketones, fluorinated ethers, and fluorinated alkenes, e.g. selected from the group consisting of (chloro)fluoroketones, (chloro)fluoroethers and (chloro)fluoroalkenes.

9. The method of claim 1, wherein the halogenated compound is a compound of formula R.sup.1C(O)R.sup.2 or R.sup.1OR.sup.2, where: R.sup.1 is C.sub.(n)H.sub.(2n+1x)Hal.sub.(x), R.sup.2 is selected from C.sub.(n)H.sub.(2n+1) and C.sub.(n)H.sub.(2n+1x)Hal.sub.(x), each n is independently selected from integers greater than or equal to 1, each x is independently selected from integers greater than or equal to 1, each Hal is a halogen atom, independently selected from F, Cl, Br and I.

10. The method of claim 9, wherein where each Hal is F.

11. The method of claim 1, wherein where the test fluid is or comprises: CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2, (CF.sub.3).sub.2CFC(O)CF(CF.sub.3).sub.2, CF.sub.3CF.sub.2CF.sub.2C(O)CF(CF.sub.3).sub.2, or a mixture of two or more thereof.

12. The method of claim 1, wherein said pressure vessel is a fire extinguisher.

13. The method of claim 1, wherein said method comprises measuring the volumetric distortion of the vessel at the test pressure.

14. The method of claim 1, wherein said method comprises recovering the test fluid.

15. Use of a test fluid in pressure-testing of pressure vessel, wherein the test fluid is as defined in claim 1.

Description

EXAMPLE 1

Fluoroketone Hydro Test

[0155] 1. Select the pressure vessel to be tested. Ensure burst discs are installed. Pressure switch/TCPT should be removed. Fill plug and gasket should be removed. All other ports should be welded closed.

[0156] 2. Seal pressure switch port.

[0157] 3. Fill container completely with CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2 through the pressure switch port.

[0158] 4. Install pressure switch port plug with pressure transducer attached.

[0159] 5. Install fill port adapter to allow pressurization with nitrogen.

[0160] 6. Place the vessel in a fixture located inside hydro test booth.

[0161] 7. Set up the pressure transducer to monitor cylinder pressure.

[0162] 8. Increase cylinder pressure to 6.2 MPa test pressure (e.g. for a fire extinguisher) by applying nitrogen pressure and hold for 1 minute.

[0163] 9. Record volumetric expansion.

[0164] 10. Record the maximum pressure obtained within the cylinder via the pressure transducer.

[0165] 11. Vent pressure slowly from the test vessel.

[0166] 12. Recycle/recover liquid CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2 via Haskell pump.

[0167] 13. Connect a vacuum pump to the fill valve and pull a vacuum of at least 20 mercury (10 psi, 67728 Pa) on the cylinder. Hold this vacuum for 5 minutes.

[0168] 14. Remove the vacuum pump and pressure switch plug.

[0169] It will be understood that the description above relates to a non-limiting example and that various changes and modifications may be made from the arrangement shown without departing from the scope of this disclosure, which is set forth in the accompanying claims.

[0170] It will be understood from the above that the disclosure in its embodiments may provide the advantage of allowing pressure testing of pressure vessels without the safety hazards of pneumatic testing and without contamination issues which can be experienced from existing hydrostatic testing methods.