GB2450905A

GB2450905A - Apparatus for testing pipeline integrity

Info

Publication number: GB2450905A
Application number: GB0713446A
Authority: GB
Inventors: Michael Eric Flanagan
Original assignee: Advanced Sewer Products Ltd
Current assignee: Advanced Sewer Products Ltd
Priority date: 2007-07-11
Filing date: 2007-07-11
Publication date: 2009-01-14
Also published as: GB0713446D0

Abstract

A unit (101) for testing pipeline integrity comprising a housing (102) that has an air outlet (107) for connecting to a hose, and a pressure sensor (210, figure 2B) located within the housing. The sensor is configured to generate an electrical signal in response to air pressure within the outlet. The unit also includes a pump (106) located within the housing for pumping air through the outlet to raise air pressure within the outlet, and a display means (109) configured to display a pressure sensed by the sensor.

Description

I

Apparatus For Testing Pipeline Integrity

Technical Field

The present invention relates to apparatus and a method for testing pipeline integrity.

Background of the Invention

It is common practice for the air-tightness of a drain or sewer pipeline to be tested by locating pipe-stoppers in each of the open ends of the pipeline, increasing air pressure within the pipeline and measuring the drop in air pressure over a defined period of time. The equipment used for such a test includes a bulb-type pump (that is actuated by squeezing) and a manometer. Both the bulb pump and the manometer are connected to a nipple on one of the pipe-stoppers by lengths of flexible tubing and a T-piece.

* . The manometer itself comprises a stand which supports a U-shaped tube and also a scale (typically in millimetres). Before use the U-shaped tube must be filled to a required level with water, and the manometer positioned * a.

* such that the U-shaped tube is both upright and observable by a person performing the test. Each of these tasks requires both a degree of dexterity and time, and may be made more difficult by relatively dark, cold conditions within the hole in the ground in which the pipeline is located.

Brief Summary of the Invention

According to an aspect of the present invention, there is provided a unit for testing pipeline integrity, comprising: a housing having an air outlet for connecting to a hose; a pressure sensor located within said housing, said sensor being configured to generate an electrical signal in response to air pressure within said outlet; and a pump located within said housing for pumping air through said outlet to raise air pressure within said outlet; and a display means configured to display a pressure sensed by said sensor.

Brief Description of the Several Views of the Drawings Figure 1 shows a unit 101 for testing pipeline integrity; Figures 2A and 2B respectively show a side view and cross-sectional side view of the unit 101; Figure 3 shows the unit 101 being used to perform an air test on a pipeline 301; and Figures 4A and 4B show cross-sectional side views of an alternative unit 401 in two different configurations. S... * I *S..

Description of the Best Mode for Carrying out the Invention : Figure 1 A unit 101 for testing pipeline integrity is shown in the perspective S...

view of Figure 1. The unit 101 comprises a housing 102 having a main body 103 and a lever 104 connected to said main body by a hinge mechanism 115. The main body 103 is provided with a handle portion 105, and the handle portion 105 and lever 104 are configured to be held, and squeezed together, within a hand of a user.

A pump 106 is located within the housing 102 and is configured to provide a flow of air to an outlet 107 of the housing defined by a nipple. In the present embodiment, the pump comprises an envelope defining a chamber, and the envelope is located between the handle portion 105 and lever 104. Consequently, a user is able to pump air through said outlet by squeezing together the handle portion 105 and the lever 104, thereby squashing the envelope to reduce the volume of its chamber.

The unit 101 also comprises a display 108. The display in the present example includes a liquid crystal display (LCD) panel 109 providing a numeric display of the air pressure above ambient that is present within the outlet 107. The LCD has a back-light (not shown) that is arranged to be illuminated during use. Consequently, the display panel 109 is readable in locations where light levels are low, without an additional light source being necessary.

For ease of use, the display 108 also includes an array of light emitting diodes 110 of varying colours which graphically indicate air pressures that are critical during the test. Thus, it is not necessary for a user to read the LCD, because instead they may simply observe which of the LEDs are illuminated. * * **..

The unit 101 also comprises an on/off button 111 for switching on or off circuitry within the unit that drives the display panel and receives signals S..

from the pressure sensor.

A selector button 112 is provided to allow a user to choose the units of pressure measurement displayed by the LCD panel 109.

A pressure-release button 113 is provided on the housing 102 that is operable by a user to release air and lower air pressure within the outlet 107.

Figure 2 The unit 101 is shown in the side view of Figure 2A and cross-sectional side view of Figure 2B. As may be seen in Figure 2B, the pump 106 comprises a rubber bulb 201 having an ovoid-shaped outer wall 202 defining a chamber 203. At one end of the bulb 201 the wall 202 defines an inlet 204 provided with a non-return valve 205. At the opposite end, the wall 202 defines an outlet 206 connected to a hose 207 which is itself connected to the unit's outlet 107 via a pressure release valve 208 and T-piece 209. A side-arm of the T-piece 209 is itself connected to the pressure sensor 210 by a second hose 211. Consequently, the pressure sensor is connected to the outlet 107, allowing the air-pressure at the outlet to be sensed.

The pressure sensor is configured to sense air pressures between 0 and 120mm of water, and may be of the type sold by Sensorlechnics for use in medical instrumentation.

The pressure sensor 210 is mounted on a circuit board 212 having :. circuitry configured to supply the required voltages to the sensor 210, and :..::: measure the output voltages from the sensor. In addition, the circuitry is configured to drive the display panel 109 and LEDs 110 in response to the : measured output signals from the sensor 210. S..

As illustrated in Figure 2B, the pressure release button 113 is S...

operatively connected to the pressure release valve 208 allowing a user to *. ..

: * * release air pressure from the outlet 107 by depression of said button.

Figure 3 The unit 101 is shown in Figure 3 being used to perform an air test on a pipeline 301. The pipeline may be complete, or partly completed. In either case, the test is for the purpose of ensuring that the joints of the pipeline do not leak.

The first step in the method of testing is to position a pipe-stopper in the open ends 302, 303 of the pipeline 301. One stopper 304 is configured to provide a complete seal at the end of the pipeline, while the other pipe-stopper 305 seals the other end of the pipeline but has a nipple 306 providing access to a passageway through the pipe-stopper.

In the present example, the pipe-stoppers 304 and 305 are as described in the applicant's patent published as GB 2 399 613. Thus, they each comprise a pair of circular plates 307, 308 separated by an expandable seal 309, and a lever 310 having a cam surface which, on operation of the lever 310, brings the two plates together to expand the seal 309. Thus, in use, the pipe-stoppers 304, 305 are located within the open ends of the pipeline 301 and their levers 310 actuated to expand the seals 309 against the inside wall of the pipeline.

The nipple 306 of the pipe-stopper 305 is connected to the nipple 107 of the unit 101 by a flexible tube 311. The person 312 performing the test then holds the handle 105 and lever 104 of the unit 101 in their hand * * * *..

and repetitively squeezes, so that the pump 106 pumps air, through the : tube 311 and pipe-stopper 305, into the pipeline 301. While pumping, the **.

person 312 observes the pressure displayed on the display 109, and then stops pumping when the required pressure is reached. ** *.

* * Typically the apparatus shown in Figure 3 is used for testing the pipeline, in accordance with European standard EN 1610. In this case, air is pumped into the pipeline until a pressure of 120mm of water is attained.

This pressure is held for a period of time, of 5 to 10 minutes, to allow for temperature stabilisation within the pipeline. The user then depresses the pressure release button 113 such that air is released from the pipeline via pressure release valve 208 until a pressure of 100mm of water is reached.

The pressure is then monitored for a period of five minutes, and the pipeline is considered to be sufficiently airtight provided the pressure remains over 75mm of water during that period.

Figure 4 An alternative unit 401 embodying the present invention is shown in cross-section in Figures 4A and 4B. The unit 401 is identical to the unit 101 of Figure 1 except the internal surfaces 431, 432 of the handle 405 and lever 404 are contoured so that when they are brought together they provide a constriction to pinch the hose 407 to close it off. In addition, a metal hoop 421 is pivotally mounted on the free end of the lever 404, while the free end of the handle 405 is provided with a groove 422 for receiving a portion of the hoop.

Thus, as shown in Figure 4A, the pump 406 of unit 401 may be operated in the same manner as pump 106 of unit 101. However, when a required pressure is reached, the lever 404 and handle 405 are brought together and the hoop rotated to locate it in the groove 422 of the handle. In this configuration, shown in Figure 4B, the hoop 421 locks the handle and lever 405 together, and the inner contoured surfaces of the handle and lever pinch the hose 407 to close it off. By pinching the hose 407 in this way, the user of the unit cannot inadvertently actuate the pump and invalidate the test.

The unit 401 therefore uses the handle 405 and lever 404 in combination to both actuate the pump 406, and effectively provide a stop valve by pinching the hose 407. In a further alternative embodiment the unit is provided with a separate stop valve, to prevent inadvertent pumping through the outlet 107.

Although each of the above described embodiments include a manually actuated pump, other embodiments are envisaged that make use of electrically operated pumps.

Claims

Claims 1. A unit for testing pipeline integrity, comprising: a housing

having an air outlet for connecting to a hose; a pressure sensor located within said housing, said sensor being configured to generate an electrical signal in response to air pressure within said outlet; and a pump located within said housing for pumping air through said outlet to raise air pressure within said outlet; and a display means configured to display a pressure sensed by said sensor. * . * *** *. * .

*S.* -
2. A unit for testing pipeline integrity in accordance with claim 1, wherein said unit comprises an illuminated display means. ** * ****
3. A unit for testing pipeline integrity in accordance with claim I or :. claim 2, wherein said display means comprises a liquid crystal display (LCD).
4. A unit for testing pipeline integrity in accordance with any of claims 1 to 3, wherein said display means comprises an array of light emitting diodes (LEDs).
5. A unit for testing pipeline integrity in accordance with any of claims I to 4, wherein said pump comprises an envelope defining a chamber, and said pump is operated by deforming said envelope to reduce the volume of said chamber.
6. A unit for testing pipeline integrity in accordance with claim 5, wherein said envelope comprises a resilient bulb.
7. A unit for testing pipeline integrity in accordance with claim 5 or claim 6, wherein said envelope is located between hinged members forming said housing, such that in operation said envelope is compressed between said hinged members.
8. A unit for testing pipeline integrity in accordance with any of :. claims I to 7, wherein said pressure sensor comprises a diaphragm and said electrical signal depends upon movement of said diaphragm. **..

:
9. A unit for testing pipeline integrity in accordance with any of claims I to 8, wherein said unit comprises a release valve configured to *::::* allow air pressure within said outlet to be reduced. *. *. * * * * *
10. A unit for testing pipeline integrity in accordance with any of claims 1 to 9, wherein said release valve is configured to be operated by a user while said user views said display means.
11. A unit for testing pipeline integrity in accordance with any of claims I to 10, wherein said unit is provided with means for preventing inadvertent flow of air to the outlet.
12. Apparatus for testing pipeline integrity, comprising: a housing having an air outlet for connecting to a hose; a pressure sensor located within said housing, said sensor being configured to generate an electrical signal in response to air pressure within said outlet; a pump located within said housing for pumping air through said outlet to raise air pressure within said outlet; a display means configured to display a pressure sensed by said sensor; and a pipe-stopper configured to provide a seal within a pipe and having an aperture in communication with said outlet of said housing to allow air passing through said outlet to pass though said aperture and into a pipe sealed by said pipe-stopper. * * * ***
13. A method of testing pipeline integrity comprising the steps of: : locating a pipe-stopper in each of the open ends of a pipeline; **.

connecting an outlet of a unit to a nipple on one of said pipe-**** stoppers; ** a.

: * . actuating a pump within said unit to pump air into said pipeline; receiving air into a pressure sensor located within said unit, such that said sensor generates an electrical signal; and providing a display indicative of said generated signal.
14. Apparatus for testing pipeline integrity substantially as herein described with reference to the accompanying Figures.
15. A method of testing pipeline integrity substantially as herein described with reference to the accompanying Figures.