GB1579347A - Calibration of flowmeters - Google Patents

Calibration of flowmeters Download PDF

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Publication number
GB1579347A
GB1579347A GB469/45/76A GB4694576A GB1579347A GB 1579347 A GB1579347 A GB 1579347A GB 4694576 A GB4694576 A GB 4694576A GB 1579347 A GB1579347 A GB 1579347A
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GB
United Kingdom
Prior art keywords
flow meter
flow
subsidiary
indicated
meter
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
GB469/45/76A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
UK Atomic Energy Authority
Original Assignee
UK Atomic Energy Authority
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 UK Atomic Energy Authority filed Critical UK Atomic Energy Authority
Priority to GB469/45/76A priority Critical patent/GB1579347A/en
Publication of GB1579347A publication Critical patent/GB1579347A/en
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
    • G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
    • G01F25/13—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters using a reference counter

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Volume Flow (AREA)

Description

(54) IMPROVEMENTS IN OR RELATING TO THE CALIBRATION OF FLOWMETERS (711) We, UNITED KINGDOlWl ATOMIC ENERGY AUTHORITY, London, a British Authority, 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 the calibration of flow meters, and more specifically, to the on-site checking of flow meters. The present invention is applicatbie to flow meters for use with all types of fluids.
According to the present inventiorr there is provided a method of calibrating a flow meter comprising the operations of placing a subsidiary, previously calibrated, flow meter in parallel with the flow meter to be calibrated, observing the change in the flow rate indicated by the flow meter under calibration and comparing the change in the indicated flow rate with that indicated by the subsidiary flow meter.
A characteristic curve for the flow meter can be obtained by repeating the operation with differing flow rates through the subsidiary flow meter.
The subsidiary flow meter can be of either positive-displacement or turbine type, and pre ferably is installed down stream of a flow straightening device.
A method of calibrating a flow meter embodying the invention will now be described, ,by way of example, with reference to the drawing accompanying the Provisional Specification.
Referring to the drawing, a flow metering system 1 incorporated into a natural gas pipeline 2 consists of a flow straightener 3 mounted upstream of a turbine type flow meter 4. Two stop valves 5 and 6, respectively, enable the portion of the pipe line 2 incorporating the flow metering system 1 to be isolated should it be necessary in order that maintenance or other operations on the flow metering system 1 can be carried out. Upstream of the stop valve 5 and down stream of the stop valve 6 are T-pieces and stop valves 7 and 8, respectively.
The stop valves 7 and 8 have a considerably smaller bore than that of the main pipe line 2 and flow metering system 1. Inserted between the stop valves 7 and 8 is a subsidiary flow meter 9 and flow-straightener 10. As shown, the subsidiary flow meter 9 is a turbinetype flow meter, but other types of flow meter, such as a positive displacement flow meter can be used. The only requirement is that the subsidiary flow meter is one which has been accurately calibrated against a primary standard of flow measurement.
In use, to check the calibration of the main flow meter 4, the stop valves 7 and 8 are closed and stop valve 6 is adjusted until a given flow rate Q is indicated by the flow meter 4. The stop valves 7 and 8 are then opened and adjusted to allow a small flow rate Q, a few per cent of Q to flow through the subsidiary flow meter 9. The decrease A a in the flow rate indicated by the main flow meter is then compared with A Q, as indicated by the subsidiary flow meter.
A characteristic for the main flow meter 4 can be obtained by repeating the procedure for verious values of Q and plotting the values of the ratio A Q/A u against various values of Q. The curve so obained is peculiar to any given flow meter 4, and in fact is the differential of the calibration curve of the flow meter 4. Thus it can be used to detect any changes in the calibration of the flow meter 4.
The method is particularly useful for checking whether the viscosity of the fluid flowing through the flow meter 4, or bearing friction is affecting the performance of rotating flow meters such as turbine and positive displacement meters.
If desired, after any given main flow meter has been checked, the subsidiary flow meter 9 and its associated pipework can be removed and used to check another flow meter at a different flow measuring station along the pipe line 2.
WHAT WE CLAIM IS: 1, A method of calibrating a flow meter comprising the operations of placing a subsidiary, previously calibrated, flow meter in
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    (54) IMPROVEMENTS IN OR RELATING TO THE CALIBRATION OF FLOWMETERS (711) We, UNITED KINGDOlWl ATOMIC ENERGY AUTHORITY, London, a British Authority, 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 the calibration of flow meters, and more specifically, to the on-site checking of flow meters. The present invention is applicatbie to flow meters for use with all types of fluids.
    According to the present inventiorr there is provided a method of calibrating a flow meter comprising the operations of placing a subsidiary, previously calibrated, flow meter in parallel with the flow meter to be calibrated, observing the change in the flow rate indicated by the flow meter under calibration and comparing the change in the indicated flow rate with that indicated by the subsidiary flow meter.
    A characteristic curve for the flow meter can be obtained by repeating the operation with differing flow rates through the subsidiary flow meter.
    The subsidiary flow meter can be of either positive-displacement or turbine type, and pre ferably is installed down stream of a flow straightening device.
    A method of calibrating a flow meter embodying the invention will now be described, ,by way of example, with reference to the drawing accompanying the Provisional Specification.
    Referring to the drawing, a flow metering system 1 incorporated into a natural gas pipeline 2 consists of a flow straightener 3 mounted upstream of a turbine type flow meter 4. Two stop valves 5 and 6, respectively, enable the portion of the pipe line 2 incorporating the flow metering system 1 to be isolated should it be necessary in order that maintenance or other operations on the flow metering system 1 can be carried out. Upstream of the stop valve 5 and down stream of the stop valve 6 are T-pieces and stop valves 7 and 8, respectively.
    The stop valves 7 and 8 have a considerably smaller bore than that of the main pipe line 2 and flow metering system 1. Inserted between the stop valves 7 and 8 is a subsidiary flow meter 9 and flow-straightener 10. As shown, the subsidiary flow meter 9 is a turbinetype flow meter, but other types of flow meter, such as a positive displacement flow meter can be used. The only requirement is that the subsidiary flow meter is one which has been accurately calibrated against a primary standard of flow measurement.
    In use, to check the calibration of the main flow meter 4, the stop valves 7 and 8 are closed and stop valve 6 is adjusted until a given flow rate Q is indicated by the flow meter 4. The stop valves 7 and 8 are then opened and adjusted to allow a small flow rate Q, a few per cent of Q to flow through the subsidiary flow meter 9. The decrease A a in the flow rate indicated by the main flow meter is then compared with A Q, as indicated by the subsidiary flow meter.
    A characteristic for the main flow meter 4 can be obtained by repeating the procedure for verious values of Q and plotting the values of the ratio A Q/A u against various values of Q. The curve so obained is peculiar to any given flow meter 4, and in fact is the differential of the calibration curve of the flow meter 4. Thus it can be used to detect any changes in the calibration of the flow meter 4.
    The method is particularly useful for checking whether the viscosity of the fluid flowing through the flow meter 4, or bearing friction is affecting the performance of rotating flow meters such as turbine and positive displacement meters.
    If desired, after any given main flow meter has been checked, the subsidiary flow meter 9 and its associated pipework can be removed and used to check another flow meter at a different flow measuring station along the pipe line 2.
    WHAT WE CLAIM IS: 1, A method of calibrating a flow meter comprising the operations of placing a subsidiary, previously calibrated, flow meter in parallel with the flow meter to be calibrated, observing the change in the flow rate indicated by the flow meter under calibration and comparing the change in the indicated flow rate with that indicated by the subsidiary flow meter.
  2. 2. A method according to claim 1 wherein the operations are repeated with differing flow rates through the subsidiary flow meter and a characteristic curve for the flow meter to be calibrated is derived.
  3. 3. A method according to claim 1 or claim 2 wherein the subsidiary flow meter is of a positive-displacement type.
  4. 4. A method according to claim 1 or claim 2 wherein the subsidiary flow meter is of a turbine type.
  5. 5. A method according to any preceding claim wherein the subsidiary flow meter is installed downstream of a flow-straightening device.
  6. 6. A method substantially as hereinbefore described with reference to the drawing accompanying the Provisional Specification.
GB469/45/76A 1977-11-10 1977-11-10 Calibration of flowmeters Expired GB1579347A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB469/45/76A GB1579347A (en) 1977-11-10 1977-11-10 Calibration of flowmeters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB469/45/76A GB1579347A (en) 1977-11-10 1977-11-10 Calibration of flowmeters

Publications (1)

Publication Number Publication Date
GB1579347A true GB1579347A (en) 1980-11-19

Family

ID=10443166

Family Applications (1)

Application Number Title Priority Date Filing Date
GB469/45/76A Expired GB1579347A (en) 1977-11-10 1977-11-10 Calibration of flowmeters

Country Status (1)

Country Link
GB (1) GB1579347A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4706492A (en) * 1986-06-16 1987-11-17 Chevron Research Company Method and apparatus for determining real gas effects in critical flow nozzles
WO1995002806A1 (en) * 1993-07-15 1995-01-26 Euromatic Machine & Oil (Co) Uk Limited Calibrating flow meters
GB2294550A (en) * 1993-07-15 1996-05-01 Euromatic Machine & Oil Calibrating flow meters
CN114704239A (en) * 2022-03-14 2022-07-05 中国海洋石油集团有限公司 Online calibration method for cable-controlled separate injection well flowmeter

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4706492A (en) * 1986-06-16 1987-11-17 Chevron Research Company Method and apparatus for determining real gas effects in critical flow nozzles
WO1995002806A1 (en) * 1993-07-15 1995-01-26 Euromatic Machine & Oil (Co) Uk Limited Calibrating flow meters
GB2294550A (en) * 1993-07-15 1996-05-01 Euromatic Machine & Oil Calibrating flow meters
CN114704239A (en) * 2022-03-14 2022-07-05 中国海洋石油集团有限公司 Online calibration method for cable-controlled separate injection well flowmeter

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee