Pipeline leak detector apparatus and method

• US 5,072,621 A
• Filed: 06/25/1990
• Issued: 12/17/1991
• Est. Priority Date: 06/25/1990
• Status: Expired due to Fees

• Current Assignee: Delaware Capital Formation Incorporated (Dover Corporation)
• Original Assignee: Detlev E.M. Hasselmann
• Inventors: Hasselmann, Detlev E. M.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Kau, Shu-Cheng
• Application Number:
  US07/543,355
• Time in Patent Office: 540 Days
• Field of Search: 73/40.5 R, 73/49.1, 73/49.5, 73/49.2 R
• US Class Current: 73/40.50R
• CPC Class Codes: G01M 3/2892 for underground fuel dispensing systems G01M3/30 takes precedence

Abstract

A method for detecting leaks in a fluid pipeline where the pressure supply pump remains ON during the test procedure and pressure on both sides of a closed shut-off valve in the pipeline is maintained equal. A novel flow meter is provided comprising a parallel combination of a solenoid value and a pressure differential switch connected across the shut-off valve.

Claims

1. Pipeline leak detector apparatus comprising:

a liquid containing tank;

dispenser valve means remote from said tank;

liquid conduit means connected between the interior of said tank and said dispenser valve means;

shut-off valve means in said conduit means intermediate said tank and said dispenser valve means;

pump means coupled in said conduit means on the tank side of said shut-off valve means and configured to apply fluid under pressure to said liquid conduit means and said dispenser valve means; and

flow meter means connected in said conduit means in parallel with said shut-off valve means, said flow meter means and said shut-off valve means being a parallel combination in series with said pump means, said flow meter means being configured to maintain equal pressure on both sides of said shut-off valve means and to indicate any liquid flow therethrough.

2. The apparatus recited in claim 1, and further comprising:

flow meter verification valve means having an input side and an output side, said input side being connected to said conduit means intermediate said shut-off valve means and said dispenser valve means; and

orifice means in said conduit means connected to said output side of said verification valve means, said orifice means having a predetermined fluid flow rate therethrough.

3. The apparatus recited in claim 1, wherein said flow meter means comprises:

flow meter valve means connected in said conduit means in parallel with said shut-off valve means;

pressure differential switch means connected in parallel with said flow meter valve means; and

means for operatively coupling said switch to said flow meter valve means to open and close said flow meter valve means in response to pressure changes in said liquid conduit means.

4. The apparatus recited in claim 3, and further comprising:

means for monitoring flow detected by said flow meter means for a predetermined period of time;

means for establishing a predetermined flow rate set point;

means for determining rate of flow through said flow meter means; and

indicator means for indicating that the conduit means has met the predetermined flow rate or has failed to meet the predetermined flow rate.

5. The apparatus recited in claim 1, and further comprising indicator means for indicating liquid flow through said flow meter means.

6. The apparatus recited in claim 1, and further comprising:

means for monitoring flow detected by said flow meter means for a predetermined period of time;

means for establishing a predetermined flow rate set point;

means for determining rate of flow through said flow meter means; and

indicator means for indicating that the conduit means has met the predetermined flow rate or has failed to meet the predetermined flow rate.

7. A method for detecting leaks in a pipeline, the pipeline being connected between a liquid containing tank and a dispenser valve, there being a pump to apply the liquid under pressure to the pipeline, a shut-off valve in the pipeline between the pump and the dispenser valve, and a flow meter connected in the pipeline in parallel with the shut-off valve, the combination of the flow meter and the shut-off valve being in series with the pump, said method comprising the steps of:

closing the dispenser valve;

energizing the pump to apply liquid under pressure to the pipeline;

then

closing the shut-off valve while maintaining the pump energized; and

then

determining whether or not there is liquid flow through the flow meter.

8. The method recited in claim 7, and comprising the further steps of:

connecting the input side of a flow meter verification valve in the pipeline;

connecting an orifice to the output side of said verification valve;

opening the verification valve to create an artificial leak; and

determining whether or not the flow meter indicates flow when the verification valve is open.

9. The method recited in claim 8, wherein the verification valve is cycled open and closed to create an artificial leak to verify flow and no-flow conditions of the flow meter.

10. The method recited in claim 7, wherein the flow meter is formed of a flow meter valve and pressure differential switch connected in parallel, the switch operatively controlling the opening and closing of the flow meter valve, said flow determining step comprising the steps of:

sensing pressure reduction in the pipeline by means of the pressure differential switch;

opening the flow meter valve to equalize the pressure on both sides of the shut-off valve;

measuring the length of time the flow meter valve stays on; and

calculating the amount of flow through the flow meter valve.

11. The method recited in claim 10, and comprising the further steps of:

integrating a plurality of calculations of the amount of flow through the flow meter valve over a measured period of time; and

calculating the leak rate of the pipeline.

12. The method recited in claim 10, and comprising the further steps of:

monitoring liquid flow detected by the flow meter for a predetermined period of time;

establishing a predetermined flow rate set point;

determining rate of flow through said flow meter; and

indicating whether or not the flow through the flow meter is below said set point.

13. The method recited in claim 7, and comprising the further steps of:

monitoring liquid flow detected by the flow meter for a predetermined period of time;

establishing a predetermined flow rate set point;

determining rate of flow through said flow meter; and

indicating whether or not the flow through the flow meter is below said set point.

14. The method recited in claim 7, and comprising the further step of maintaining equal pressure of both sides of the shut-off valve by keeping the flow meter closed when there is no pressure differential across the shut-off valve and opening the flow meter to equalize the pressure in response to a pressure differential.

15. Pipeline leak detector apparatus comprising:

a liquid containing tank;

dispenser valve means remote from said tank;

liquid conduit means connected between the interior of said tank and said dispenser valve means;

shut-off valve means in said conduit means intermediate said tank and said dispenser valve means;

pump means coupled in said conduit means on the tank side of said shut-off valve means and configured to apply fluid under pressure to said liquid conduit means and said dispenser valve means; and

flow meter means connected in said conduit means in parallel with said shut-off valve means, said flow meter means indicating any liquid flow therethrough.

16. The apparatus recited in claim 15, wherein said flow meter means is normally closed and opens in response to the pressure differential across said shut-off valve means to thereby maintain equal pressure on both sides of said shut-off valve means.