WO2015008895A1

WO2015008895A1 - Bi-directional pipe prover without prerun

Info

Publication number: WO2015008895A1
Application number: PCT/KR2013/008430
Authority: WO
Inventors: Ki Chul Cha; Jung Hwan Ahn
Original assignee: Woojin Inc.
Priority date: 2013-07-18
Filing date: 2013-09-17
Publication date: 2015-01-22
Also published as: KR101531020B1; KR20150010834A

Abstract

Provided is a bi-directional pipe prover for calibrating a flowmeter under test based on a reference volume ejected when a sphere moves in a predetermined area of a measuring pipe having the reference volume. The pipe prover for calibrating a flowmeter includes: a prover pipe that has a reference volume; and a head unit that is provided on an end portion of the prover pipe, wherein a flowmeter under test is calibrated based on a volume of a fluid ejected when a sphere moves between detectors in the prover pipe, wherein the head unit whose one side communicates with an inlet (or an outlet) and whose other side is connected to the prover pipe, and that provides the sphere along with the fluid into the prover pipe, includes: a space unit in which the sphere stays by evading a movement passage of the fluid; and a first position adjusting unit that is provided in the space unit in order to adjust a position of the sphere staying in the space unit and provide the sphere to the movement passage of the fluid.

Description

BI-DIRECTIONAL PIPE PROVER WITHOUT PRERUN

The present invention relates to a pipe prover for calibrating a flowmeter, and more particularly, to a bi-directional pipe prover that calibrates a flowmeter under test based on a reference volume that is ejected when a sphere moves in a predetermined area of a measuring pipe unit having the reference volume.

Measuring a flow rate is important in improving efficiency and managing an operation in fluid or energy commerce and production facility. Since measurement accuracy of a flowmeter that is used to measure a flow rate is very important, many methods are used to verify the accuracy. One of the methods is a method using a pipe prover related to the present invention. This method involves comparing a measurement value of the flowmeter under test with the amount of a fluid ejected while one sphere moves between two detectors in the pipe prover.

Although there are various types of pipe provers, the pipe provers are roughly classified into bi-directional pipe provers and uni-directional pipe provers. Bi-directional pipe provers have advantages in that structures are standardized and reliability is high, but have disadvantages in that since a maximum velocity of a sphere is designed to be 1.5 m/s and a pre-run area of the sphere has to be secured, there is a spatial limitation during installation. By contrast, uni-directional pipe provers have advantages in that since a maximum velocity of a sphere that moves a measuring pipe is 3 m/s, a cross-sectional area of the measuring pipe may be reduced, and since a pre-run area is not required, the measuring pipe may be economically designed, but have disadvantages in that structures are not standardized and reliability is low.

FIG. 1 is a plan view illustrating a conventional bi-directional pipe prover. As shown in FIG. 1, the bi-directional pipe prover includes a prover pipe 10 having a reference volume. Two detectors D1 and D2 are provided in the prover pipe 10, and header units 20 each having a diameter greater than a diameter of the prover pipe 10 are respectively provided on both ends of the prover pipe 10.

An inlet 30a and an outlet 30b are connected to the two header units 20, and a 4-way valve 40 is provided between the inlet 30a and the outlet 30b. A flowmeter under test (not shown) is provided in any one of the inlet 30a and the outlet 30b of the pipe prover, and the inlet may act as an outlet and the outlet may act as an inlet due to the 4-way valve 40. That is, the flow direction of a fluid may be changed by manipulating the 4-way valve 40. For example, the 4-way valve 40 may be manipulated such that the inlet 30a to which the flowmeter under test is attached and one header unit 20a communicate with each other and the outlet 30b and the other header unit 20b communicate with each other. In this case, the fluid before the flow direction is changed is filled in the prover pipe 10 and the header units 20, and a sphere (not shown) that is moved from the prover pipe 10 is disposed in advance in any of the header units 20.

In the pipe prover constructed as described above, a flow velocity of the fluid introduced into the header units 20 gradually increases as an opening degree of the 4-way valve 40 increases. Measurement is performed when the flow velocity finally reaches a predetermined flow velocity and the sphere having the predetermined flow velocity along with the fluid moves along an area between the detectors D1 and D2 in the prover pipe 10. Next, measurement is performed when the flow direction of the fluid is changed by manipulating the 4-way valve 40 and the sphere moves along the area between the detectors D2 and D1 in the opposite direction.

The conventional bi-directional pipe prover is designed such that after the fluid passing through the flowmeter under test is entirely introduced into the prover pipe 10 and a predetermined flow velocity is reached, the sphere passes through the detectors D1 and D2. Accordingly, in order for the sphere to reach the predetermined flow velocity, a predetermined pre-run area P has to be secured in the prover pipe 10. In the conventional pipe prover, the pre-run area P of about 9 to 10 m is generally used for the prover pipe 10 of 30 inches, and a length of the pre-run area P may vary according to a switching time of the 4-way valve and a flow rate. As the pre-run area is secured, the conventional bi-directional pipe prover has problems in that there is a difficulty in securing a space during installation of the pipe prover and installation costs according to the space are high.

Also, in the conventional bi-directional pipe prover, as the pre-run area is secured, a maximum velocity of the sphere is set to be 1.5 m/s. In this case, since a pipe having a large diameter of 30 inches has to be used as the prover pipe 10 in order to have a flow rate of 2400 m³/h, material costs are increased and thus it is difficult to reduce production costs.

Also, the conventional bi-directional pipe prover has another disadvantage in that since it is not easy to insert and remove the sphere, it is difficult to check and maintain the pipe prover.

[Reference Document] KR 10-2007-0000440

The present invention is directed to providing a pipe prover that may be economically designed and may reduce a spatial limitation during installation by removing a pre-run area for a sphere.

Also, the present invention is directed to providing a pipe prover for calibrating a flowmeter that may increase a maximum velocity of a sphere by removing a pre-run area and thus may reduce material costs by using a prover pipe having a small diameter.

Also, the present invention is directed to providing a pipe prover for calibrating a flowmeter that may be easily checked and maintained by enabling a sphere to be easily inserted into and removed from a head unit.

One aspect of the present invention provides a pipe prover for calibrating a flowmeter, the pipe prover including: a prover pipe that has a reference volume; and a head unit that is provided on an end portion of the prover pipe, wherein a flowmeter under test is calibrated based on a volume of a fluid ejected when a sphere moves between detectors in the prover pipe, wherein the head unit whose one side communicates with an inlet (or an outlet) and whose other side is connected to the prover pipe, and that provides the sphere along with the fluid into the prover pipe, includes: a space unit in which the sphere stays by evading a movement passage of the fluid; and a first position adjusting unit that is provided in the space unit in order to adjust a position of the sphere staying in the space unit and provide the sphere to the movement passage of the fluid.

The space unit may be provided under the movement passage of the fluid, and the first position adjusting unit may be a vertical cylinder that adjusts a vertical position of the sphere.

The head unit may further include a second position adjusting unit of a horizontal cylinder that adjusts a horizontal position of the sphere in order for the sphere to be easily inserted into the prover pipe; and an opening/closing unit that is provided over the space unit in order to insert and remove the sphere into and from the head unit.

Cylinders of the first position adjusting unit and the second position adjusting unit may be multi-step cylinders, and the head unit may form a stepped portion having a predetermined height with respect to the prover pipe in order for the sphere to be easily inserted into the prover pipe.

According to the present invention configured as described above, since a separate space in which a sphere may stay is secured while a fluid flowing in a prover pipe reaches a sufficient velocity and the sphere is provided to a movement passage of the fluid when the fluid reaches a predetermined flow velocity, a separate pre-run area for the sphere is not required, thereby economically designing the pipe prover, reducing a spatial limitation during installation, and reducing production costs such as material costs, processing costs, and land costs.

Also, according to the present invention, since an operation velocity (that is, a velocity of a sphere) is increased, a loop size of a prover pipe is reduced, thereby reducing production costs.

In addition, according to the present invention, since maintenance and repair through an opening/closing unit and vertical cylinder is possible without removing a fluid filled in the prover pipe while being maintained and repaired, calibration and maintenance may be easily performed.

FIG. 1 is a plan view illustrating a conventional bi-directional pipe prover for calibrating a fluid.

FIG. 2 is a plan view illustrating a bi-directional pipe prover for calibrating a fluid, according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating an internal structure of a head unit that is an essential unit of FIG. 2.

FIG. 4 is a cross-sectional view illustrating a state in which a vertical position of a sphere is adjusted in the head unit of FIG. 3.

FIG. 5 is a cross-sectional view illustrating a state in which a horizontal position of the sphere is adjusted in the head unit of FIG. 3.

FIG. 6 is a cross-sectional view illustrating a state in which the sphere is removed from the head unit of FIG. 3.

Exemplary embodiments of the present invention are referred to in order to gain a sufficient understanding of the present invention and the objectives accomplished by the implementation of the present invention. The present invention will now be described in detail by explaining exemplary embodiments of the present invention with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

FIG. 2 is a plan view illustrating a bi-directional pipe prover for calibrating a fluid, according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line A-A, illustrating an internal structure of a head unit that is an essential unit of FIG. 2.

First, as shown in FIG. 2, in the bi-directional pipe prover of the present invention, head units 200 are provided on both ends of a prover pipe 100 having a reference volume, a fluid pipe 300 is connected as an inlet 300a or an outlet 300b to each of the head units 200, and each fluid pipe 300 functions as the inlet 300a or the outlet 300b due to a 4-way valve 400.

Here, the prover pipe 100 that is a pipe having a diameter of 24 inches and an entire length of the prover pipe 100 forms a reference volume area in which a fluid moves. An entire shape of the prover pipe 100 is a ‘U’ shape, and the head units 200 are connected to both end portions of the prover pipe 100. Also, detectors D1 and D2 are provided on a start point and an end point of the prover pipe 100 that forms the reference volume area to detect a sphere 110 that flows in the pipe. In particular, since the prover pipe 100 of the present invention does not include an area (that is, a pre-run area) for accelerating the sphere 110, the prover pipe 100 may be designed such that the fluid flows at a velocity of 3.0 m/s. Accordingly, in order to have a flow rate of, for example, 2400 m³/h, a pipe having a loop size (diameter) of 24 inches instead of a pipe having a loop size (diameter) of 30 inches may be used.

The 4-way valve 400 for controlling in both flow directions of the fluid through the prover pipe 100 controls a flow direction of the fluid so that the fluid pipe 300 connected to each of the head units 200 functions as the inlet 300a or the outlet 300b.

The head units 200 each having a diameter greater than that of the prover pipe 100 are provided on both end portions of the prover pipe 100, and enable the sphere 110 to be detected while moving in both directions along with the fluid. The fluid pipe 300 is connected as the inlet 300a or the outlet 300b to one side of the head units 200, and the prover pipe 100 is connected to the other side in parallel to the fluid pipe 300.

In particular, the head units 200 of the present invention are configured such that a space in which the sphere 110 may stay is secured and thus the sphere 110 is inserted into the prover pipe 100 in a state in which the fluid reaches a predetermined velocity (v=3.0 m/s). Accordingly, the present invention does not include a separate pre-run area for moving the sphere 110 until the fluid reaches a predetermined velocity. That is, referring to FIG. 1, a conventional pipe prover requires a pre-run area P for moving the sphere 110 until the 4-way valve completely rotates and the fluid reaches a predetermined velocity whereas the present invention does not require a separate pre-run area as shown in FIG. 2 and the head units 200 are directly connected to the prover pipe 100 that forms the reference volume area R. In this configuration, the pipe prover may be economically designed and there is little spatial limitation during installation.

Referring to FIG. 3 illustrating a structure of one of the head units of the present invention, a space unit 210 in which the sphere 110 may stay is secured under the head unit 200 as shown in FIG. 3A. Also, a first position adjusting unit 230 for adjusting a position of the sphere is provided under the space unit 210.

The space unit 210 is provided under a movement passage 100a of the fluid in order for the sphere 110 to evade the movement passage 100a of the fluid, and when an initial flow of the fluid occurs, the sphere 110 stays in the space unit 210. Next, when the fluid reaches a predetermined velocity (3.0 m/s) as shown in FIG. 3B, the sphere 110 is moved from the space unit 210 to the movement passage 100a, is inserted into the prover pipe 100, and moves along with the fluid in the prover pipe 100. In this case, measurement is performed when the sphere 110 passes through the detectors D1 and D2 that are provided on both ends of the prover pipe 100.

Meanwhile, a position of the sphere 110 is adjusted by the first position adjusting unit 230, and the first position adjusting unit 230 is a vertical hydraulic cylinder. That is, as shown in FIG. 3, the first position adjusting unit 230 that is a vertical hydraulic cylinder is provided under the space unit 210, and a vertical piston 231 of the hydraulic cylinder vertically operates in the space unit 210. Accordingly, the vertical piston 231 vertically moves the sphere 110 toward the movement passage 100a through which the fluid flows. In this case, an operation of the first position adjusting unit 230 and a velocity of the fluid that is introduced are adjusted by an additional control device (not shown).

Also, the head unit 200 of the present invention further includes a second position adjusting unit 240 for adjusting a horizontal position of the sphere 110. The sphere 110 whose vertical position is changed by the first position adjusting unit 230 may not be directly inserted into the prover pipe 100. A horizontal piston 241 of the second position adjusting unit 240 that is a horizontal hydraulic cylinder may push the sphere 110 toward the prover pipe 100, so that the sphere 110 is easily inserted into the prover pipe 100. The second position adjusting unit 240 is horizontally provided in the inlet 300a through which the fluid is introduced to be parallel to the inlet 300a.

It is preferable that the first position adjusting unit 230 and the second position adjusting unit 240 of the present invention are respectively a vertical hydraulic cylinder and a horizontal hydraulic cylinder, and a piston of each of the cylinders has a multi-step structure. A cylinder including a piston having a multi-step structure may minimize a width in a longitudinal direction, thereby efficiently using a space during construction.

Also, the head unit 200 of the present invention includes an opening/closing unit 220 for inserting and removing the sphere 110. The sphere 110 is inserted into and removed from the head unit 200 through the opening/closing unit 220. The opening/closing unit 220 is provided vertically over the space unit 210. Accordingly, the sphere 110 is easily removed from the head unit 200 through the opening/closing unit 220 during a removal operation of the vertical piston 231 of the first position adjusting unit 230 provided in the space unit 210.

Meanwhile, the head unit 200 constructed as described above is stepwise connected to the prover pipe 100 to have a predetermined stepped portion D. In this case, the head unit 200 is at a higher position than the prover pipe 100, and a connection unit between the head unit 200 and the prover pipe 100 is inclined. Due to the head unit 200 that is stepwise connected, the sphere 110 may be easily inserted into the prover pipe 100. In particular, when the pipe prover is checked, since the fluid filled in the prover pipe 100 does not need to be removed, calibration and maintenance may be easily performed.

Adjustment of a position of the sphere in the head unit of the present invention will be explained in detail below with reference to the drawings. FIG. 4 is a cross-sectional view illustrating a state in which a vertical position of the sphere is adjusted in the head unit of FIG. 3. FIG. 5 is a cross-sectional view illustrating a state in which a horizontal position of the sphere is adjusted. FIG. 6 is a cross-sectional view illustrating a state in which the sphere is removed.

First, a vertical position of the sphere in the head unit of the present invention is adjusted by the first position adjusting unit 230 that is a vertical cylinder provided in the space unit 210 as shown in FIG. 4. That is, the fluid is introduced into the head unit 200 through the inlet 300a under control of the 4-way valve 400, and since the first position adjusting unit 230 does not operate until the fluid reaches a predetermined velocity at an initial stage at which the fluid flows again through the prover pipe 100, the sphere 110 stays in the space unit 210. Next, when the 4-way valve 400 is completely opened and the fluid flows at the predetermined velocity, the first position adjusting unit 230 operates to vertically move upward the sphere. In this case, the sphere 110 is inserted into the prover pipe 100 as the fluid flows, and moves along with the fluid in the prover pipe 100.

Meanwhile, in this process, the second position adjusting unit 240 that is a horizontal cylinder may also operate in order for the sphere 110 to be easily inserted into the prover pipe 100. That is, as shown in FIG. 5, when a vertical position of the sphere 110 is changed by the first position adjusting unit 230, a horizontal cylinder of the second position adjusting unit 240 horizontally pushes the sphere 110 so that the sphere 110 is easily inserted into the prover pipe 100.

As shown in FIG. 6, the sphere is removed from the head unit of the present invention through the opening/closing unit 220 that is provided over the sphere. That is, the first position adjusting unit 230 moves upward the sphere 110 in the head unit to reach the opening/closing unit 220, and the sphere 110 exposed to the outside of the head unit 200 may be easily removed out. In a state in which the sphere 110 is removed, a state of the sphere 110 and an inside of the head unit 200 may be checked. In this case, since the head unit 200 forms a stepped portion having a predetermined height with respect to the prover pipe 100, even when the fluid is filled in the prover pipe 100, the head unit may be tested.

As described above, since a bi-directional pipe prover of the present invention has an improved structure of head units that are coupled to both ends of a prover pipe, material costs and installation costs may be reduced and checking and maintenance may be easily performed.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Description of Reference Numerals

100: prover pipe

110: sphere

200: head unit

210: space unit

220: opening/closing unit

230: first position adjusting unit

231: vertical piston

240: second position adjusting unit

241: horizontal piston

300: fluid pipe

300a: inlet

300b: outlet

400: 4-way valve

Claims

A pipe prover for calibrating a flowmeter, the pipe prover comprising:

a prover pipe that has a reference volume; and

a head unit that is provided on an end portion of the prover pipe,

wherein a flowmeter under test is calibrated based on a volume of a fluid ejected when a sphere moves between detectors in the prover pipe,

wherein the head unit whose one side communicates with an inlet (or an outlet) and whose other side is connected to the prover pipe, and that provides the sphere along with the fluid into the prover pipe, comprises:

a space unit in which the sphere stays by evading a movement passage of the fluid; and

a first position adjusting unit that is provided in the space unit in order to adjust a position of the sphere staying in the space unit and provide the sphere to the movement passage of the fluid.
The pipe prover of claim 1, wherein the space unit is provided under the movement passage of the fluid, and

the first position adjusting unit is a vertical cylinder that adjusts a vertical position of the sphere.
The pipe prover of claim 1, wherein the head unit further comprises a second position adjusting unit of a horizontal cylinder that adjusts a horizontal position of the sphere in order for the sphere to be easily inserted into the prover pipe.
The pipe prover of claim 1, wherein the head unit further comprises an opening/closing unit that is provided over the space unit in order to insert and remove the sphere into and from the head unit.
The pipe prover of any of claims 1 through 4, wherein cylinders of the first position adjusting unit and the second position adjusting unit are multi-step cylinders.
The pipe prover of any of claims 1 through 4, wherein the head unit forms a stepped portion having a predetermined height with respect to the prover pipe in order for the sphere to be easily inserted into the prover pipe.