GB2177220A

GB2177220A - Method and apparatus for pressure testing components

Info

Publication number: GB2177220A
Application number: GB08612720A
Authority: GB
Inventors: Michael Brian Brotherton
Original assignee: BROTHERTON ENGINEERING Ltd
Current assignee: BROTHERTON ENGINEERING Ltd
Priority date: 1985-07-10
Filing date: 1986-05-23
Publication date: 1987-01-14
Also published as: GB8612720D0; GB2177220B; GB8517485D0

Abstract

A blind bore B is pressure tested by the inflation of an elastic bag 12 therein. An initial stage of the inflation causes the open end of the bag to seal with mounting means therefor. The bag is mounted on a mandrel 10 by an integral flange 13 held between a seat 16 of the mandrel and a nut 17 secured to the mandrel. An annular groove 14 in the inner surface of flange 13 locates a circumferential flange 15 of the mandrel. Fluid under pressure introduced to the bag via inlet 18 causes the external surfaces of flange 13 to seal with the nut and mandrel. Shaped bags or a plurality of bags may be employed to test complex bores. <IMAGE>

Description

SPECIFICATION Method and apparatus for pressure testing components This invention concerns a method and apparatus for pressure testing the integrity of a blind bore in a component such as a casting or machined part and wherein pressure is applied to the interior walls of such blind bore.

Testing such components using a pressure hydraulic fluid applied directly to the inner walls of the bore can be hazardous because of the high pressure sometimes necessary and the possibility of entrained air which can give rise to an explosive hazard in the event of any failure of the component.

It is an object of the present invention to provide a method of pressure testing a blind bore in a component which overcomes the problem aforesaid.

According to the present invention there is provided a method of pressure testing a blind bore in a component comprising the steps of providing an elastic bag extending from mounting means for its open end, positioning said bag within the blind bore component and inflating the bag with hydraulic fluid to the required test pressure, the arrangement being such that an initial stage of the inflation causes the open end of the bag to cooperate with said mounting means to form an effective pressure seal which prevents leakage of fluid from the interior of the bag at the test pressure.

The bag may be supported over a mandrel adapted to enter the blind bore and which may be part of said mounting means.

The invention will be further apparent from the following description, with reference to the single figure of the accompanying drawing, which shows, by way of example only, in cross-section, one form of apparatus for pressure testing a blind bore in a component of generally cylindrical form.

Referring to the drawing, it will be seen that the component C is mounted in a vertical position with the open end of its blind bore B directed downwardly.

A tubular mandrel 10 having an open upper end extends from a machine frame member 11 to support a bag 12 of elastic rubber material within the bore B.

The lower open end of the bag 12 is provided with an integrally formed outwardly extending circumferential flange 13 having an internal annular groove 14 which iocates a circumferential flange 15 on the lower end of the mandrel just above a portion 16 thereof of enlarged cross-sectional area forming a seat for the lower face of the flange 13. A nut member 17 threadedly engages the portion 16 and has a recess to locate the flange 13.

Hydraulic fluid under pressure may be supplied through a bore 18 in the portion 16 to pass upwardly through the mandrel 10 and into the space between the mandrel 10 and bag 12 to inflate the bag and apply pressure radially to the walls of the bore B.

An initial stage of the inflation pressurises all of the external surfaces of the flange 13 into engagement with their surrounding parts to form a seal preventing leakage of hydraulic fluid from the open end of the bag at test pressure which may be as high, for example, as 17,500 psi.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof as defined in the appended claims.

Thus for example with bores of more complex shape a bag of corresponding shape may be employed or a plurality of bags may be used which can be individually inflated to the same or different pressures as desired in a plurality of bores in a single component.

The techniques of the present invention may be practised in combination with those described in our co-pending Application No.

8423280 for the testing of voids open at both ends.

1. A method of pressure testing a blind bore in a component comprising the steps of providing an elastic bag extending from mounting means for its open end, positioning said bag within the blind bore component and inflating the bag with hydraulic fluid to the required test pressure, the arrangement being such that an initial stage of the inflation causes the open end of the bag to cooperate with said mounting means to form an effective pressure seal which prevents leakage of fluid from the interior of the bag at the test pressure.

2. Apparatus for pressure testing a blind bore in a component comprising an elastic bag extending from mounting means for its open end and adapted to be positioned within said blind bore and means for inflating said bag with hydraulic fluid to the required test pressure, the arrangement being such that an initial stage of the inflation causes the open end of the bag to cooperate with said mounting means to form an effective pressure seal which prevents leakage of fluid from the interior of the bag at the test pressure.

3. Apparatus according to claim 2 wherein the open end of the bag is integrally formed with an outwardly extending circumferential flange having an internal annular groove.

4. Apparatus according to claim 3 wherein said flange is located within a cylindrical recess defined by said mounting means.

5. Apparatus according to claim 4 wherein said recess is defined between a nut member which fits over the flange and threadly en

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method and apparatus for pressure testing components This invention concerns a method and apparatus for pressure testing the integrity of a blind bore in a component such as a casting or machined part and wherein pressure is applied to the interior walls of such blind bore. Testing such components using a pressure hydraulic fluid applied directly to the inner walls of the bore can be hazardous because of the high pressure sometimes necessary and the possibility of entrained air which can give rise to an explosive hazard in the event of any failure of the component. It is an object of the present invention to provide a method of pressure testing a blind bore in a component which overcomes the problem aforesaid. According to the present invention there is provided a method of pressure testing a blind bore in a component comprising the steps of providing an elastic bag extending from mounting means for its open end, positioning said bag within the blind bore component and inflating the bag with hydraulic fluid to the required test pressure, the arrangement being such that an initial stage of the inflation causes the open end of the bag to cooperate with said mounting means to form an effective pressure seal which prevents leakage of fluid from the interior of the bag at the test pressure. The bag may be supported over a mandrel adapted to enter the blind bore and which may be part of said mounting means. The invention will be further apparent from the following description, with reference to the single figure of the accompanying drawing, which shows, by way of example only, in cross-section, one form of apparatus for pressure testing a blind bore in a component of generally cylindrical form. Referring to the drawing, it will be seen that the component C is mounted in a vertical position with the open end of its blind bore B directed downwardly. A tubular mandrel 10 having an open upper end extends from a machine frame member 11 to support a bag 12 of elastic rubber material within the bore B. The lower open end of the bag 12 is provided with an integrally formed outwardly extending circumferential flange 13 having an internal annular groove 14 which iocates a circumferential flange 15 on the lower end of the mandrel just above a portion 16 thereof of enlarged cross-sectional area forming a seat for the lower face of the flange 13. A nut member 17 threadedly engages the portion 16 and has a recess to locate the flange 13. Hydraulic fluid under pressure may be supplied through a bore 18 in the portion 16 to pass upwardly through the mandrel 10 and into the space between the mandrel 10 and bag 12 to inflate the bag and apply pressure radially to the walls of the bore B. An initial stage of the inflation pressurises all of the external surfaces of the flange 13 into engagement with their surrounding parts to form a seal preventing leakage of hydraulic fluid from the open end of the bag at test pressure which may be as high, for example, as 17,500 psi. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof as defined in the appended claims. Thus for example with bores of more complex shape a bag of corresponding shape may be employed or a plurality of bags may be used which can be individually inflated to the same or different pressures as desired in a plurality of bores in a single component. The techniques of the present invention may be practised in combination with those described in our co-pending Application No. 8423280 for the testing of voids open at both ends. CLAIMS

5. Apparatus according to claim 4 wherein said recess is defined between a nut member which fits over the flange and threadly en gages a part forming a seat for the outer face of the flange.

6. Apparatus according any one of claims 3 to 5 including a mandrel extending within the bag from its open end to form a support for the bag.

7. Apparatus according to claim 6 wherein said mandrel is tubular and serves for the supply of hydraulic fluid to the interior of the bag.

8. Apparatus according to claim 6 or claim 7 wherein said mandrel includes an outwardly extending circumferential flange which locates in said annular groove.

9. Apparatus according to any one of claims 2 to 8 wherein said bag is of rubber.

10. Apparatus for pressure testing a blind bore substantially as described herein with reference to and as illustrated by the single figure of the accompanying drawing.