GB1602172A - Device for pressure testing - Google Patents

Device for pressure testing Download PDF

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Publication number
GB1602172A
GB1602172A GB5182576A GB5182576A GB1602172A GB 1602172 A GB1602172 A GB 1602172A GB 5182576 A GB5182576 A GB 5182576A GB 5182576 A GB5182576 A GB 5182576A GB 1602172 A GB1602172 A GB 1602172A
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GB
United Kingdom
Prior art keywords
pressure
gauge
manifold
valve
test
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB5182576A
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MEDAL CONSULTANTS Ltd
Original Assignee
MEDAL CONSULTANTS Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MEDAL CONSULTANTS Ltd filed Critical MEDAL CONSULTANTS Ltd
Priority to GB5182576A priority Critical patent/GB1602172A/en
Publication of GB1602172A publication Critical patent/GB1602172A/en
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
    • G01M3/32—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for containers, e.g. radiators
    • G01M3/3236—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for containers, e.g. radiators by monitoring the interior space of the containers
    • G01M3/3263—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for containers, e.g. radiators by monitoring the interior space of the containers using a differential pressure detector
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
    • G01N3/12—Pressure testing

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measuring Fluid Pressure (AREA)

Description

(54) IMPROVEMENTS IN OR RELATING TO A DEVICE FOR PRESSURE TESTING (71) We MEDAL CONSULTANTS LIMITED a Company organised under the laws of the Isle of Man of 8 St Georges Street, Douglas, Isle of Man, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a device for pressure testing of a body.
When testing a body such as a closed pipeline, vessel, or other container it is usual to pressurise the closed pipeline etc., to a required test pressure either hydraulically or pneumatically, then to measure a pressure drop or difference between initial and final readings which can vary between a period of several minutes to many days depending upon the size and volume ofthe measured vessel. Adjustments usually then have to be made to the pressure readings taken for temperature rise or fall, barometric pressure rise or fall and if the initial test and final test are at different elevations above or below sea level.
The more common instruments used for these tests are Deadweight Testers, Dial Type Pressure Gauges, Single Column Manometers and 'U' type double Limb Gauges.
By far the most common and accurate is the Deadweight Tester with an approximate 0.01 psi accuracy, but again prone to temperature and barometric changes, besides which the weights needed for balancing against the test pressure are heavy and just as cumbersome as the deadweight tester itself.
The deadweight tester is cumbersome and extremely costly to manufacture.
According to the present invention, there is provided a device for pressure testing of a body, comprising a housing, a connector for connecting the housing to the body so as to allow equalisation of pressure in the device and the body, means for isolating pressure fluid in a part of the housing from that in the remainder of the housing, a compensator comprising an extensible container of variable volume connected to the part of the housing to accommodate pressure fluid which may be displaced due to a change in pressure and means for indicating such a change in pressure disposed in a pressure fluid connection connected across and to opposite sides respectively of the means for isolating.
In order that the invention may be more clearly understood one embodiment of the invention will now be described by way of example only, with reference to the single figure of the accompanying drawing which shows diagrammatically a front elevational view in cross section of one form of the testing device.
Referring to the drawing, the device comprises a U-gauge 5 made up with two synthetic plastics material or glass tubes 5A and 5B.
At the top of the tubes SA and SB is disposed a manifold 11 which is drilled to produce ports at C and D to receive the tops of the tubes 5A and SB. Four bores 2A, 2B, 2C and 2D, are also drilled in the manifold 11, 2A and 2B leading from the ports C and D to meet the bore 2D substantially at right angles, and to cross it to points A and B. Valves 3 and 7 are disposed respectively on bores 2D and 2C. A valve 10, is disposed in the bore 2D, at or near the entry point F. An inlet in the form of a bulbous nozzle 8 is provided adjacent the valve 10. Instead of a nozzle, the inlet connection may be in the form of a threaded aperture, or quick release connection. The bore 2C is drilled from the top of the manifold 11 to meet the bore 2D and has connected to it a pressure gauge 9 sufficient in range to denote the initial test pressure. This pressure gauge 9 is connectec to the bore 2C at E.Alternatively a relief valve could be connected in place of the pressure gauge.
A compensating reservoir 4 is connected to bore 2A at A sufficient in displacement volume to accept the true volume which would be created by the displacement ofliquid or measuring media 1 such as water in column 5A when movement of 1 takes place and of such design to accept the test pressure.
A compensating reservoir 6 is connected to bore 2B at B sufficient in displacement volume to which would be created by the displacement of fluid or measuring media 1 in column 5B when movement of 1 takes place and of such design to accept the test pressure. Instead of the bellows type reservoir shown, an expandable or stretchable bladder or container may be used preferably confined in a housing. Alternatively, piston and cylinder devices may be used.
A graduated scale 12 is provided marked in divisions to the scale required.
The manifold 11 may be formed, cast or machined in metal or synthetic plastics material.
Although the manifold 11 is shown in one piece it can be made up of separate parts to form the same pattern of the manifold shown. The scale 12 may be of synthetic plastics material or metal, etched, machined engraved or printed with appropriate divisions. The valves 3, 7 and 10, may be needle valves, ball valves, plug valves or any other similar design to manipulate the measured media. Alternatively, one valve may be designed to perform in the place of several valves shown. The tubes 5A and 5B are filled with liquid or measuring media such as water so that both limbs are level at or near the zero mark on the scale. The operation of the device is as follows. The input connection 8 is suitably connected to the pipeline, vessel, container or body to be tested.The pipeline is pressurised, and valves 3,7 and 10 open without detrimental effect to the test. When the working test pressure is reached by observing the gauge 9, settlement of pressure within the pipeline and the test instrument is allowed for a short period of time.
Valve 3 is then opened, if not already open, to allow equivalent pressure in both columns 5A and SB. Next, valve 3 and valve 7 are closed and in so doing a reference pressure is locked between gauge fluid 1 in column 5A, valve 3 and compensating reservoir 4. Pressure drop or pressure increase will then be observed by reading the difference between the level of fluid in column 5A with the level of fluid in column SB.
The difference is the pressure drop or increase of the pipeline, container or body tested. The time lapse from initial to final reading may vary from a few minutes to several days. The height of the pressure drop or rise can be calculated or 'observed' by reading the different levels in the limbs.
To measure higher pressure differentials mercury or liquids of higher specific gravity than water can be used which reduces the overall height of the instrument, or a differential pressure gauge for example of the dial type, Bubble Test Gauge or similar could be substituted for the two limbs 5A and SB.
The device described above does not use norneed to allow for barometer pressure, temperature or atmospheric pressure nor does it bodily have to be bulky heavy or sophisticated. Change in pressure is measured by locking off a sample of the gas at an initial test pressure and using it as a reference pressure against which the final test pressure of the gas is measured. The gas sample and the remainder ofthe gas are disposed on opposite sides of a measuring means. Any variation of barometric or atmospheric pressure affects both reference pressure and test pressure through the extensibility of the compensating reservoirs 4 and 6 both of which equally oppose their own contained pressure against barometric or atmospheric pressure.
It is advisable but not necessary that the test pressure of the pipeline to be tested is known in order that under certain tests the test pressures are kept within agreed recommendations. It is not so necessary to have reservoir 6 connected for short term pressure measurement as the possible difference of barometric pressure would not normally be sufficient to alter the accuracy of the pressure difference shown on the scale.
The above described embodiments have, of course, been described by way of example only and may other embodiments are possible without departing from the scope of the invention. For example miniaturisation of the manifolds by sophisticated valve set ups could be made for example push valves, multi-port valves etc., and microbore tubes could be used..
A diaphragm of leather, rubber, metal or plastics material may be used instead of the 'U' gauge 5 and the 'locked off or reference pressure to be made to oppose the working or active pressure using the diaphragm as the measuring instrument and measurements taken of the deflection of the diaphragm.
A differential gauge could be used in place of the 'U' gauge 5 to measure the difference of pressures between the reference and working pressure.
A relief valve set to a recognised pressure may be connected in place of the pressure gauge 9 which would indicate when the desired pressure had been reached and would drain away surplus pressure. The relief valve would then be isolated from the measuring instrument by closing valve 7.
Apart from specific pressure testing as referred to above, the device also has many other applications. For example, the device could be connected to a leaking water system and the pressure drop measured over a predetermined time period to determine the seriousness of the leak. It could also be used to show whether a pneumatic tyre is leaking or not.
In this specification, the term pressure has been used in the absolute sense and it will be appreciated that the apparatus of the invention is suitable not only for determining differences in pressure in the usual sense of the term, but also differences in vacuum.
WHAT WE CLAIM IS: 1. A device for pressure testing of a body, comprising a housing, a connector for connecting the housing to the body so as to allow equalisation of pressure in the device and the body, means for isolating pressure fluid in a part of the housing from that in the remainder of the housing, a compensator comprising an extensible container of variable volume connected to the part of the housing to accommodate pressure fluid which may be displaced due to a change in pressure and means for indicating such a change in pressure disposed in a pressure fluid connection connected across and to opposite sides respectively of the means for
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (24)

**WARNING** start of CLMS field may overlap end of DESC **. A graduated scale 12 is provided marked in divisions to the scale required. The manifold 11 may be formed, cast or machined in metal or synthetic plastics material. Although the manifold 11 is shown in one piece it can be made up of separate parts to form the same pattern of the manifold shown. The scale 12 may be of synthetic plastics material or metal, etched, machined engraved or printed with appropriate divisions. The valves 3, 7 and 10, may be needle valves, ball valves, plug valves or any other similar design to manipulate the measured media. Alternatively, one valve may be designed to perform in the place of several valves shown. The tubes 5A and 5B are filled with liquid or measuring media such as water so that both limbs are level at or near the zero mark on the scale. The operation of the device is as follows. The input connection 8 is suitably connected to the pipeline, vessel, container or body to be tested.The pipeline is pressurised, and valves 3,7 and 10 open without detrimental effect to the test. When the working test pressure is reached by observing the gauge 9, settlement of pressure within the pipeline and the test instrument is allowed for a short period of time. Valve 3 is then opened, if not already open, to allow equivalent pressure in both columns 5A and SB. Next, valve 3 and valve 7 are closed and in so doing a reference pressure is locked between gauge fluid 1 in column 5A, valve 3 and compensating reservoir 4. Pressure drop or pressure increase will then be observed by reading the difference between the level of fluid in column 5A with the level of fluid in column SB. The difference is the pressure drop or increase of the pipeline, container or body tested. The time lapse from initial to final reading may vary from a few minutes to several days. The height of the pressure drop or rise can be calculated or 'observed' by reading the different levels in the limbs. To measure higher pressure differentials mercury or liquids of higher specific gravity than water can be used which reduces the overall height of the instrument, or a differential pressure gauge for example of the dial type, Bubble Test Gauge or similar could be substituted for the two limbs 5A and SB. The device described above does not use norneed to allow for barometer pressure, temperature or atmospheric pressure nor does it bodily have to be bulky heavy or sophisticated. Change in pressure is measured by locking off a sample of the gas at an initial test pressure and using it as a reference pressure against which the final test pressure of the gas is measured. The gas sample and the remainder ofthe gas are disposed on opposite sides of a measuring means. Any variation of barometric or atmospheric pressure affects both reference pressure and test pressure through the extensibility of the compensating reservoirs 4 and 6 both of which equally oppose their own contained pressure against barometric or atmospheric pressure. It is advisable but not necessary that the test pressure of the pipeline to be tested is known in order that under certain tests the test pressures are kept within agreed recommendations. It is not so necessary to have reservoir 6 connected for short term pressure measurement as the possible difference of barometric pressure would not normally be sufficient to alter the accuracy of the pressure difference shown on the scale. The above described embodiments have, of course, been described by way of example only and may other embodiments are possible without departing from the scope of the invention. For example miniaturisation of the manifolds by sophisticated valve set ups could be made for example push valves, multi-port valves etc., and microbore tubes could be used.. A diaphragm of leather, rubber, metal or plastics material may be used instead of the 'U' gauge 5 and the 'locked off or reference pressure to be made to oppose the working or active pressure using the diaphragm as the measuring instrument and measurements taken of the deflection of the diaphragm. A differential gauge could be used in place of the 'U' gauge 5 to measure the difference of pressures between the reference and working pressure. A relief valve set to a recognised pressure may be connected in place of the pressure gauge 9 which would indicate when the desired pressure had been reached and would drain away surplus pressure. The relief valve would then be isolated from the measuring instrument by closing valve 7. Apart from specific pressure testing as referred to above, the device also has many other applications. For example, the device could be connected to a leaking water system and the pressure drop measured over a predetermined time period to determine the seriousness of the leak. It could also be used to show whether a pneumatic tyre is leaking or not. In this specification, the term pressure has been used in the absolute sense and it will be appreciated that the apparatus of the invention is suitable not only for determining differences in pressure in the usual sense of the term, but also differences in vacuum. WHAT WE CLAIM IS:
1. A device for pressure testing of a body, comprising a housing, a connector for connecting the housing to the body so as to allow equalisation of pressure in the device and the body, means for isolating pressure fluid in a part of the housing from that in the remainder of the housing, a compensator comprising an extensible container of variable volume connected to the part of the housing to accommodate pressure fluid which may be displaced due to a change in pressure and means for indicating such a change in pressure disposed in a pressure fluid connection connected across and to opposite sides respectively of the means for
isolating.
2. A device as claimed in claim 1, in which the pressure fluid connection comprises a Ushaped tube adapted to accommodate a liquid to form an isolating barrier between the two arms of the 'U'.
3. A device as claimed in claim 2, in which the compensator communicates with the upper free end of one arm of the 'U'.
4. A device as claimed in claim 3, in which the open upper free ends of the 'U' extend into a manifold which is ducted to provide communication between the arms of the 'U' and between the compensator and the upper free end of the said one arm.
5. A device as claimed in any preceding claim, in which the means for isolating comprises a valve.
6. A device as claimed in claim 4 or 5, in which the manifold is also ducted to provide communication between the 'U' and the connector.
7. A device as claimed in claim 4, 5, or 6 in which the manifold is also ducted to provide communication between the 'U' and a pressure gauge or relief valve,
8. A device as claimed in any of claims 4 to 7, in which the manifold is formed cast or machined.
9. A device as claimed in any of claims 4 to 8, in which the manifold is made of metal.
10. A device as claimed in any of claims 4 to 8 in which the manifold is made of synthetic plastics material.
11. A device as claimed in any preceding claim, in which the connector comprises a bulbous nozzle.
12. A device as claimed in any of claims 1 to 10 in which the connector is a threaded aperture.
13. A device as claimed in any of claims 1 to 10, in which the connector is of the quick release type.
14. A device as claimed in any preceding claim, in which the means indicating comprises a pressure scale provided adjacent the housing.
15. A device as claimed in claim 14, in which the scale is made of synthetic plastics material etched machined, engraved or printed with appropriate divisions.
16. A device as claimed in claim 3, or in any of claims 4 to 16 when appendant directly or indirectly to claim 3, in which a compensator is connected to the other arm of the 'U'.
17. A device as claimed in any preceding claim, in which the or each compensator comprises a bellow.
18. A device as claimed in any preceding claim, in which the or each compensator comprises a piston and cylinder device.
19. A device as claimed in any preceding claim, in which the or each compensator comprises an expandable or retractable container.
20. A device as claimed in any of claims 1 to 17, in which the or each compensator comprises an expandable bladder.
21. A device as claimed in claim 21, in which the or each bladder is confined in a housing.
22. A device as claimed in claim 1, in which the means for indicating comprises a diaphragm.
23. A device as claimed in claim 22, in which the diaphragm is of leather, rubber, metal or synthetic plastics material.
24. A device for indicating change in pressure substantially as hereinbefore described with reference to the accompanying drawing.
GB5182576A 1978-03-09 1978-03-09 Device for pressure testing Expired GB1602172A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB5182576A GB1602172A (en) 1978-03-09 1978-03-09 Device for pressure testing

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5182576A GB1602172A (en) 1978-03-09 1978-03-09 Device for pressure testing

Publications (1)

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GB1602172A true GB1602172A (en) 1981-11-11

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GB5182576A Expired GB1602172A (en) 1978-03-09 1978-03-09 Device for pressure testing

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116818546A (en) * 2023-08-30 2023-09-29 太仓顺达磁力泵科技有限公司 Hydraulic pressure testing machine for magnetic pump shell

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116818546A (en) * 2023-08-30 2023-09-29 太仓顺达磁力泵科技有限公司 Hydraulic pressure testing machine for magnetic pump shell
CN116818546B (en) * 2023-08-30 2023-11-24 太仓顺达磁力泵科技有限公司 Hydraulic pressure testing machine for magnetic pump shell

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Legal Events

Date Code Title Description
PS Patent sealed
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee