Check valve testing system

• US 4,977,778 A
• Filed: 01/22/1990
• Issued: 12/18/1990
• Est. Priority Date: 10/29/1986
• Status: Expired due to Fees

• Current Assignee: Crane Nuclear, Inc. (Crane Company)
• Original Assignee: Movats Incorporated
• Inventors: McMennamy, John A., Nafziger, Steven
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US07/467,911
• Time in Patent Office: 330 Days
• Field of Search: 73/597, 73/168, 73/119 A, 73/572, 367/99, 367/93, 340/870.28, 340/870.3, 376/245, 376/252, 137/554
• US Class Current: 73/597
• CPC Class Codes: F16K 37/00 Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: G01S 15/08 Systems for measuring distance only indirect measurement G01S15/46
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00

Abstract

A method and apparatus for testing the operating condition of a check valve directs sound waves into the valve chamber of a check valve assembly and utilizes the collected signals of the reflected sound waves to generate various time lapse data corresponding to the valve disk position and movement, such time lapse data providing an analysis of the condition of the valve assembly.

Claims

1. Method of testing the operating condition of a fluid flow check valve including a movable check valve disk positioned in a check valve chamber defined by a check valve casting, said method comprising the steps of:

removably and temporarily locating a sound wave sending unit and a sound wave receiving unit at the check valve;

directing a sound wave at and through the check valve casting and at the check valve disk;

receiving a plurality of reflected sound waves from reflection of the directed sound wave off elements of the check valve;

generating an isolated signal from the first reflected sound wave which, after a selected delay, subsequent to the directing of the sound wave, has an energy level above a predetermined minimum level, said isolated signal corresponding to a sound wave reflected off the check valve disk,;

counting the lapsed time from the end of the selected delay until the generation of the isolated signal;

creating a signal corresponding to the lapsed time from the end of the selected delay until the generation of the isolated signal;

collecting the signal corresponding to the lapsed time from the end of the selected delay until the generation of the isolated signal;

repeating the above directing, receiving, generating, counting, creating, and collecting steps at selected intervals over a period of time; and

plotting a lapsed time versus real time curve which reveals changes in position of the check valve disk with respect to real time,

whereby the operating condition of the check valve with respect to degradation and wear of check valve elements can be determined and analyzed.

2. Method of claim 1, further comprising the step of calculating an actual position of the check valve disk at a given point in real time.

3. Method of claim 1, wherein the step of removably and temporarily locating a sound wave sending unit and a sound wave receiving unit at the check valve comprises the step of removably and temporarily locating a sound wave sending unit and a sound wave receiving unit at the same location at the check valve.

4. Method of claim 1, further comprising the step of forcing fluid through the check valve during the above mentioned steps.

5. Method of testing the operating condition of a fluid flow check valve including a movable check valve disk positioned in a check valve chamber defined by a check valve casting, said method comprising the steps of:

directing a sound wave at and through the check valve casting and at the check valve disk;

receiving a reflected sound wave reflected off the check valve disk;

counting the lapsed time from the end of a selected delay, subsequent to the directing of the sound wave, until the receipt of the reflected sound wave; and

repeating the above directing, receiving, and counting steps at selected intervals over a period of time to monitor any relative movement of the check valve disk.

6. Apparatus for testing the operating condition of a check valve, said apparatus comprising:

a check valve assembly comprising a check valve casting, said check valve casting defining a check valve chamber, and a check valve disk located inside said check valve chamber;

wave directing means externally connected to said check valve casting for directing a plurality of directed sound wave pulses at and through said check valve casting and at said check valve disk;

wave receiving means externally connected to said check valve casting for receiving a plurality of reflected sound wave pulses, each said reflected sound wave pulse of said plurality of reflected sound wave pulses corresponding to reflection of one of said directed sound wave pulses of said plurality of directed sound wave pulses off said check valve disk;

signal conditioning means connected to said wave directing means and said wave receiving means for generating a plurality of signals, each signal of said plurality of signals representing an interval of time starting from a selected point in time after directing of one of said directed sound wave pulses and ending upon receipt of the reflected sound wave pulse corresponding to said one of said directed sound wave pulses; and

recording means connected to said signal conditioning means for collecting said plurality of signals from said signal conditioning means and for graphically relating said plurality of signals to real time.

7. Apparatus of claim 6, wherein said wave directing means comprises a wave sending transducer externally connected to said check valve casting and wherein said wave receiving means comprises a wave receiving transducer externally connected to said check valve casting.

8. Apparatus of claim 6, wherein said signal conditioning means comprises:

delay means for creating a time delay after directing of each said sound wave pulse of said plurality of directed sound wave pulses, each said time delay defining said selected point in time for starting said interval of time for each said signal;

counter means for counting lapsed time during each said interval of time; and

a discriminator means for isolating signals above a minimum selected energy level.

9. Apparatus of claim 6, wherein said recording means comprises a storage oscilloscope comprising means for generating and storing data corresponding to said plurality of signals and for generating a lapsed time versus real time curve which reveals changes in position of the check valve disk with respect to real time.