JPH0458888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to volume measurement of fluids,
In particular, the present invention relates to a small flow rate calibrator used to periodically calibrate a continuous flow meter in a piping system without interrupting the flow of liquid inside the piping system. The compact flow calibrator of the present invention falls within the range of flow calibrators of the type that measure the movement of a piston moving within a cylinder. In particular, the present invention relates to a compact flow meter having improved characteristics of accuracy, reliability, infrequent and easy maintenance, simple and lightweight construction, low space requirements and operational flexibility.

[Prior art and problems]

One type of device commonly used to verify the accuracy of continuous flow meters is known as a calibration loop. The device typically includes a long tube within which a free-moving plug or sphere is propelled by a fluid flowing therethrough. By measuring the time it takes for the plug or sphere to travel from one detection switch to the other, the flow rate through the fluid flow loop can be calibrated. Devices of this type are the subject of US Pat. No. 2,948,142, US Pat. No. 2,948,143, US Pat. No. 3,423,988 and US Pat. No. 3,668,923, and US Pat. Calibration loops generally require considerable length to maintain usable accuracy. Also, the high cost of this type of equipment precludes their use except in the most urgent cases.

There is a lot of literature on how to use positive piston type flowmeters. An example of this type of flowmeter that is not particularly suited for calibration purposes is U.S. Pat.
1586834, U.S. Patent No. 2652953, U.S. Patent No.
No. 2,892,346 and US Pat. No. 4,096,747.

One example of a positive piston type flow calibrator that can be used for flow meter calibration is described in US Pat. No. 3,021,703, which includes a piston that is free to move in both directions within a calibration barrel. This piston movement is detected by two mechanical detection switches located near each end of the calibration barrel. A considerable length of tube is required to obtain a reasonable degree of accuracy. For example, if the accuracy of the detection switch is about 0.00127 m inch, a length of tube of about 12.8 m or more would be required to produce the desired ±0.02% accuracy. Furthermore, because the detection switch projects into the calibration barrel and the exhaust port is connected to the calibration barrel, the seals on the piston wear each time they pass through the switch and the exhaust port. Since the valves must be opened and closed at the same time, additional measurement inaccuracies are introduced and significant disruption of fluid flow occurs.

A device similar to US Pat. No. 3,021,703 is disclosed in US Pat. No. 3,580,045. The difference between this device and US Pat. No. 3,021,703 is that instead of a mechanical detection switch, it uses an external proximity switch that detects the passage of the steel strip over the piston. Also disclosed is a method of using a four-port spool valve to reduce the complexity of the valve structure. However, this valve seal is subject to wear and leakage and is not suitable for monitoring seal integrity.

U.S. Pat. No. 3,273,375 discloses another type of flow meter comprising an inner tubular member and an outer tubular member with a free-moving piston disposed within the inner tubular member. This construction allows for a simpler valve system and eliminates the need for pressure modification. However, because this device uses a similar external proximity switch and requires the piston to move along the exhaust port, piston seal life does not appear to be significantly improved. Furthermore, special stopping means are required to stop the movement of the piston at each end of the calibration barrel. Furthermore,
Its complex structure would make assembly and maintenance difficult.

The flow rate testers disclosed in US Pat. Nos. 3,492,856 and 4,152,922 do not require an external exhaust port on the calibration barrel. This type of device uses a flow-through piston in which a poppet valve is provided. This poppet valve is closed during the verification cycle. The poppet valve requires pressurization, such as gas, to close the valve early in the verification cycle. U.S. Pat. No. 3,492,856 uses an external proximity switch located on the calibration barrel and pulls back the piston by a cable and drum at the end of the calibration cycle.

The piston retraction means disclosed in U.S. Pat. No. 4,152,922 includes a rod connected to a measuring piston, the other end of which is provided with a retraction piston, and the retraction piston is disposed within a hydraulic cylinder. There is. The movement of the measuring piston is detected by a proximity switch which detects the movement of the retraction piston in the hydraulic cylinder. In this calibrator, entrained solids such as gravel or sand present in the fluid being measured can become trapped between the calibration barrel and the piston seal, potentially damaging the measuring piston seal. If the calibrator is used in a horizontal position, the situation becomes more serious as solid particles settle along the bottom of the cylinder.

Other problems with each of the flow rate testers mentioned above are:
A consequence of horizontal movement is that the life of the piston seal along the bottom of the piston is reduced due to the weight of the piston.

[Object and effect of the invention]

A feature of the present invention is to provide a compact flow meter that does not have the disadvantages observed with the previously described devices. Other features include providing a compact flow tester that exhibits increased accuracy and reliability, reduced space and weight requirements, simplified construction and maintenance, and increased flexibility of operation. Yet another feature is the provision of a compact flow meter with the above features that is capable of operating at high pressures. These and other features will be apparent to those skilled in the art from the description below.

The present invention also relates to the volumetric measurement of flow, and in particular to flow calibrators used to periodically calibrate continuous flow systems in piping systems without interrupting fluid flow. The flow meter of the present invention generally measures the motion of a piston moving within a cylinder, where the piston has a plurality of seals that define an annular space between the piston and the cylinder. It belongs to a type of flow meter that forms a fluid barrier inside. More particularly, the present invention relates to a miniature flow meter having means for monitoring seal integrity.

U.S. Pat. No. 3,738,153 discloses a flow meter seal monitor having a resilient ball. The hydraulic cylinder used to open and close the ball passage has a seal monitor that detects the differential pressure between the surrounding fluid and the fluid in the area between the ball passage and the cylinder piston head. However, in this patent, the piston head does not move sealingly along the test cylinder;
The seals can thus be monitored when the piston head is at rest.

A flow meter with means for monitoring piston seal integrity is described in US Pat. No. 4,372,147. This U.S. patent discloses a measurement conduit having a fluid aperture adjacent an upstream end and a downstream end and mounted coaxially within an outer housing, a piston mounted within the conduit, and a piston downstream of the piston. A flow meter is disclosed having an actuation rod projecting axially from the outer housing with its free end passing through the downstream end of the outer housing, and a piston sensing switch disposed along the length of the measurement conduit. The piston includes two seals, each surrounding the outer periphery of the piston to define an annular cavity between the seals. One end of a flexible tube helically wrapped around the rod is connected to a passageway in fluid communication with the tubular cavity, and the other end of the flexible tube is connected to the exterior of the device. During operation of the tester, fluid leakage through any seals can be detected by monitoring the internal pressure of the flexible tube with an external connection to the flexible tube.

Two, associated with a device of the type described in this U.S. patent:
There are three possible drawbacks. A first possible drawback is that the flexible tube is rotated together with the double-acting piston, leading to failure of the flexible tube after a certain period of time. A second possible drawback is that pressure differentials between the flexible tubing and the equipment fluid result in collapse or rupture of the piping system. A third possible drawback is the need for a pressurized source or bleed system. In either case, the movement of the seal over the fluid aperture in the measurement conduit complicates seal monitoring. If seal integrity is to be dynamically monitored during certification, the flexible tubing should be monitored after it has passed through the fluid aperture so that the increase or decrease in internal pressure in the flexible tubing can be observed before the certification process is completed. A control system would be required to increase or bleed the tube pressure. Furthermore, no fluid leakage through the seal would be detected during pressurization or bleed.

[Summary of the invention]

One feature of the present invention is to provide a flow meter with means for monitoring the seal integrity of a flow meter piston that overcomes many of the disadvantages of known devices.

The compact flow meter of the present invention determines flow rate by measuring the time it takes for a pusher moving through a cylinder to expel a known amount of fluid.

The compact flow meter of the present invention includes a measurement housing, an extrusion body movably disposed along the axis of the measurement housing, and means for detecting the longitudinal position of the extrusion body in the measurement housing. The housing defines three separate compartments including a hollow main cylinder and an inlet and downstream section secured to each end thereof. The main cylinder has a substantially uniform inner diameter.
The extrusion body is provided with seals along its outer periphery, these seals providing a fluid barrier when the extrusion body is placed inside the main cylinder. The cross-sectional area of the introduction section and the downstream section is larger than the cross-sectional area of the main cylinder so that fluid can flow around the extrusion body when the extrusion body is placed in either the introduction section or the downstream section. It is. Guide means are provided in the introduction section and the downstream section to maintain the extrusion body axially aligned with the main cylinder when the extrusion body is placed in the introduction section or the downstream section. Means are provided for facilitating movement of the extrusion body from the introduction section into the main cylinder at the beginning of the verification cycle. Means are also provided for returning the extrudate from the downstream section to the introduction section at the end of the assay cycle.

The operation of the small flow meter of the present invention is simple.
When the extrusion body is held in the introduction by the return means, the fluid flow to be measured is introduced into the introduction and then sent to the main cylinder and downstream. When the return means is released, the fluid flow in said aiding means and in the introduction portion moves the extrusion body towards the main cylinder. Guide means in the introducer hold the extrusion body axially aligned with the main cylinder, thereby allowing the extrusion body to smoothly enter the main cylinder. As the extrusion body enters the main cylinder, it is propelled through its interior by a measured fluid flow.

As the extrudate moves through the main cylinder, the time it takes for the extruder to travel a predetermined distance corresponding to a known quantity can be measured and this time used to calculate the flow rate. The guide means in the downstream section maintains the extrusion body in axial alignment relative to the main cylinder as it exits the main cylinder and enters the downstream section. On return of the extrusion body, the fluid flow passing through the housing is bypassed and return means are used to return the extrusion means from the downstream part, through the main cylinder, to its starting position in the introduction section. The miniature flow calibrator is then ready to perform the next validation cycle.

An advantage of the compact flow meter of the present invention is that when the extruder is placed in the inlet and downstream sections, the fluid flowing along the extruder cleans the seal of the extruder and deposits inside the seal. The objective is to show a tendency to remove solid substances that have been removed. This cleaning action extends the useful life of the extruder seal. Another advantage is that since the fluid flows along the entire length of the main cylinder and through the entire cross-sectional area, it does not create dead spots that tend to settle suspended particles, especially when operating the extruder in a horizontal position. Yet another advantage is that the extruder's lightweight construction results in less wear on the extruder seal and the inner surface of the main cylinder. The single barrel construction also facilitates assembly/maintenance operations.

In a particular embodiment of the miniature flow meter of the invention, fluid is introduced into the introduction part of the measurement housing by an introduction tube. Fluid exits the measurement housing through a drain tube that communicates with a downstream portion of the measurement housing. Means are provided for bypassing the measurement housing, the means including a valved bypass pipe connected to the inlet pipe and the outlet pipe. In a preferred embodiment, an improved bypass valve is provided that has simple structure and operation. Since this bypass valve does not require provision for a pressure difference across the valve equal to the rated internal pressure of the flow meter, the valve can be of simple poppet construction for considerably lower rated pressures, and is therefore no different from a normal valve. shows economic advantages over The improved bypass valve also has the advantage of monitoring its seal integrity without the use of an external pressure source.

In other embodiments, the extruder return means includes a hydraulic cylinder/piston. The hydraulic piston is
It is connected to the extrusion body by a rod or shaft extending into the housing in axial alignment with the main cylinder. Following the verification cycle, the extrusion body is returned to its starting position by introducing pressure oil into the hydraulic cylinder. The guide means includes a rod connecting the extrusion to the hydraulic piston and a journal bearing mounted in the wall of the housing and slidably engaged with the rod.

In other embodiments, the extrudate return means includes a hydraulic tank and a ram. A ram is connected to the extrusion body so that the extrusion body can be placed in a desired position by varying the pressure inside the tank.

Other embodiments include assistance means including a compression spring in the introduction of the housing. The spring assists the movement of the extruder into the main cylinder when the return means is released, thus eliminating the need for pressurized gas or oil to assist the extruder at the beginning of the verification cycle. In other particular embodiments, the differential pressure acting on the extrusion body provides an additional means of aiding the movement of the extrusion body into the main cylinder. This pressure differential results from the difference in effective area between the upstream and downstream surfaces of the extrusion body that are subjected to fluid pressure.

Another embodiment of the invention provides guide means comprising an extrusion pilot projecting from one side of the extrusion and an axial sleeve bearing suitably located in the downstream section or inlet tube. The axial sleeve bearing and pilot are axially aligned with the main cylinder and the sleeve is slidably engaged with the pilot. These guide means axially align the extrusions and allow smooth entry and exit of the extrusions.

In another embodiment, the detection means comprises a rod connected to the extrusion, a journal bearing disposed in the wall of the housing for sliding engagement with the rod, and a journal bearing disposed at the other end of the rod. It includes a detection flag and a plurality of detection switches that detect passage of the detection flag and simultaneously generate signals. Since the detection flag and switch are located outside the housing, very precise optical or magnetic detection switches can be used. Another advantage of the external location of the detection means is that maintenance and calibration of the miniature flow meter is greatly facilitated. Another advantage is that the sensing means is made insensitive to temperature changes in the flowing fluid and there is no need to modify the sensing switch spacing due to thermal expansion.

In other embodiments, the main cylinder is beveled at both ends and the extrusion is provided with a plurality of compressible seals. As the extrusion enters the main cylinder, the seal is circumferentially compressed. Fluid trapped within the annular space formed between the seals is also compressed. If the seals are functioning properly, the fluid pressure trapped between the seals will be higher than the fluid in the main cylinder, and this differential pressure will not dissipate until the extruder exits the main cylinder. Thus, by comparing the pressure in the annular space between the seals to line pressure, the integrity of the extrusion seal can be verified. Means are provided to verify the integrity of the extrusion seal both statically and when the extrusion is in a verification mode. In this way, the integrity of the extruder seal can be verified without taking the calibrator out of service. Because the integrity of the calibrator seal is quickly verified, errors due to fluid leakage through the seal are easily eliminated.

In other embodiments, the miniature flow meter is operated in a vertical position and includes a flexible, burst extruder seal. This particular embodiment can handle highly contaminated fluids such as crude oil.

In other embodiments, the miniature flow meter is operated in a horizontal position and includes a more rigid seal that can support the weight of the extruder. This embodiment provides a seal that can handle low lubricity fluids. The flow rate tester can also be mounted so as to be selectively placed in a horizontal or vertical position.

Optionally, means are provided for monitoring the integrity of the detector rod and extruder rod seals.

A control system is optionally provided to simplify the verification sequence. By using authorization operations, various problems with the calibrator can be minimized or identified. For example, the extruder cannot be started unless the extruder is in the starting position and the bypass valve is closed with positive sealing integrity. After the extruder reaches the end of its stroke, the bypass valve can be opened after a predetermined time delay. As soon as the bypass valve is opened, the extrusion body is returned towards its starting position. The bypass valve is closed when the extruded body exits the upstream end of the cylinder.

This miniature flow calibrator can be used to calibrate a continuous flow meter connected in series with the flow calibrator. The accuracy of the continuous flow meter is determined by comparing the electric pulses generated by the flow meter with the high-frequency electric pulses generated by the flow rate verification system when the extruded body moves a predetermined distance inside the main cylinder. be done. The volume of fluid extruded by the extruder is modified with respect to temperature/pressure expansion of the cylinder.

The flow rate tester of the present invention determines flow rate by measuring the time it takes for a pusher moving in a cylinder to push out a known amount of fluid. The flow meter of the present invention includes means for monitoring the seal integrity of the extrudate.

The flow meter of the invention comprises a measuring cylinder and a pusher or piston movably arranged inside this cylinder. The cylinder is filled with the fluid whose flow rate is to be measured by the calibrator. The extrusion includes two seals and forms a fluid barrier within the cylinder when placed inside the cylinder. These seals are mechanically compressible so that when the flow meter is activated, the annular volume of the compressed fluid is limited by the seal, the extrusion, and the cylinder. A first conduit is arranged parallel to the axis of the cylinder. One end of this conduit is connected to the extruder and its free end is accessible from outside the flow meter. The conduit has a substantially uniform diameter coaxial channel providing fluid communication between the ends of the conduit and communicating with the interseal annular space. The calibrator also includes a second conduit disposed within the channel of the first conduit. The second conduit communicates with the fluid in the cylinder and is accessible from the free end of the first conduit. Means are also provided for measuring the differential pressure between the first and second conduits.

The flow rate can be determined by measuring the time it takes for the extruder to extrude a predetermined amount of fluid. Errors due to fluid leakage past the extrusion seal are easily detected. Since the annular space between the seals is in communication with the first conduit, the pressure between the seals can be monitored. Similarly, the pressure of the fluid in the cylinder is monitored by monitoring the pressure in the second conduit. If the integrity of the seal is preserved,
Mechanical compression of the seals results in fluid pressure in the interseal annular space being greater than fluid pressure in the cylinder, and this differential pressure is maintained until the seals are decompressed. If seal integrity is lost, fluid leakage through either seal will result in a drop in differential pressure between this annular space and the cylinder fluid.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The miniature flow rate tester illustrated in FIGS. 1 to 4 includes an inlet pipe 1 and a discharge pipe 11 in fluid communication with the housing 2.
and a bypass pipe 3. Liquid enters the inlet tube 1 through port 1a, as illustrated by arrow A in FIG. 1, and exits through outlet tube 11 and out port 11a, as illustrated by arrow B in FIG. A normally closed bypass valve 4 is arranged in the bypass pipe 3 and is actuated by a bypass valve actuator 5.

The housing 2 includes an axially arranged inlet section 6, a main cylinder 9, and a downstream section 10. The upstream part 6 and the downstream part 10 are connected by bolts 9a from the cylinder 9.
It can be removed by The inlet 6 is in fluid communication with the inlet tube 1 and the main cylinder 9.
Downstream section 10 is in fluid communication with main cylinder 9 and discharge pipe 11 . The inner diameter of the main cylinder 9 is substantially uniform. The cross-sectional area of the introduction part 6 and the downstream part 10 is larger than the cross-sectional area of the main cylinder 9.

A movable extrusion body 7 is shown within the housing 9. On the outer periphery of the extruded body 7, an extruded seal 28,
29 are arranged. A shaft 8 is connected to the center of the downstream surface of the extruded body 7. The shaft 8 is inserted into a journal bearing 15 in the introduction part 6 and is connected to a hydraulic piston 16, which is slidable in a hydraulic cylinder 17, as shown in FIGS. 1 and 6. It is located in

A detection rod 19 is connected to the extrusion body 7;
It extends from the introduction part 6 through the journal bearing 20. The detection rod 19 is provided with a detection flag 21 at its downstream end. The detection unit 22 comprises precision detectors 23, 24 and 25 spaced apart from each other to detect the passage of the detection flag 21. These detectors are photomicro sensor model EE-SH3M available from Omron Corporation.
It can be a magnetic detector or an optical detector such as a linear transducer.

The downstream part guide means 10a includes an extruded body pilot 13 that comes out from the center of the upstream surface of the extruded body 7, and a downstream part 1.
7 and consists of an axial sleeve bearing concentric with the pilot 13. In order to cause the extrusion body 7 to enter the main cylinder 9 during the start mode,
A compression spring 12 surrounds the shaft 8 in the introduction part 6 .

In the embodiment shown in FIG.
is a simple poppet structure with a poppet valve 60 having a truncated cone 60a connected to an actuator shaft 63. This poppet valve 60 abuts against a valve seat 68, which is connected to an upstream flange 61 and a downstream flange 6 of the bypass pipe 3.
It is located between 2 and 2. Poppet 60 includes seals 64 and 65. An annular space 66 between these seals 64 and 65 is in fluid communication with a channel 67 formed in valve seat 68.
This channel 67 is connected to a pressure transducer or pressure element 54.

As shown in FIG. 6, the shaft 8 is a journal bearing 1.
5 and is slidably engaged by the detection rod 19.
are slidably engaged by journal bearings 20. The introduction tube 1 is bifurcated to allow fluid to enter the introduction section 6 through fluid introduction ports 26 and 27. This structure allows fluid to enter substantially longitudinally into the inlet 6 to reduce or eliminate radial and oblique stresses on the extrusion 7 and to reduce the diameter and weight of the shaft 8. . Monitoring means (not shown) may be provided for monitoring the integrity of the seals in journal bearings 15 and 20.

As shown in FIG.
is fixed to the extruded body 7 by a nut 69. However, the pilot 13 and the shaft 8 can also be of integral construction. Pilot 13 is slidably engaged in axial sleeve bearing 14 by bushing 70. Sleeve bearing 14
and pilot 13 are axially aligned inside main cylinder 9. The sleeve bearing 14 includes a channel 71 for allowing fluid to escape from the sleeve bearing 14 as the pilot 13 enters the bearing 14. This extrusion of fluid from the sleeve bearing 14 serves as a slow stop mechanism that decelerates the movement of the extrusion body 7 when it enters the downstream section 10.

The main cylinder 9 shown in FIG. 8 is chamfered at both ends so that the extruder 7 can enter smoothly. For example, for a cylinder with an inner diameter of about 0.324 m inches, a 4° chamfer surface with a length of about 0.0508 m will produce adequate results. The inner surface of the main cylinder 9 is lined with a corrosion-resistant material and honed smooth. Desirably, the cylinder 9 has a substantially uniform inner diameter to provide accurate measurements and extend the life of the extrusion seal. For example about 0.324
Approximately 0.000127 for a cylinder with an inner diameter of m±0.0000254m
It has been discovered that good results can be obtained by applying a hard chrome plating of 1.5 m and a finish of 12 root mean square (RMS) or better. The specific diameter and length of the cylinder are chosen based on the flow rate to be measured and the required accuracy.

The extruded body 7 consists of a conical part 72 and a ring part 73. It will be readily appreciated that other shapes for this extrudate can be used. Seals 28 and 29
is prevented from falling off by a retaining ring 36. An annular space 32 formed between seals 28 and 29 is in fluid communication with channel 58 of extrusion body 7. To prevent thermal pressure in the annular space 32, a volume compensator 37 is in fluid communication with the extruder channel 58 by a channel 59 of the rod 19.

As shown in FIG.
9 each include a horizontal U-shaped elastic member 34;
This member 34 has a base 34a and this member 3
4, a U-shaped metal energizer 35 is enclosed. The material of the elastic layer can be any typical material used in seals, such as polytetrafluoroethylene or polybutylene, and has chemical resistance to the fluid being measured, fluid lubricity, and compactness during operation. The choice is made based on whether the flow meter is in a horizontal or vertical orientation. The material of the energizer 35 is preferably an alloy. These seals are prevented from slipping off the extrusion 7 by a removably screwed retaining ring 36 and are retained by a band 33 of steel or aluminum.
As shown in FIG. 10, the bases 34a of seals 28 and 29 can project radially outwardly beyond ring 36. The inner lip 74 of each elastic body 34 is forced radially outward by a metal energizer 35.

FIG. 11 shows variations 28' and 2 of the extrusion seal.
9' is shown. Its base 34a' does not project radially outwardly beyond the ring 36. However, lip 74' has been forced past ring 36 by metal energizer 35'.

The volume compensator 37 includes a housing 38 , an inner tipped element 39 , an outer tipped element 41 , and an element 5 .
a compression spring 40 concentrically arranged around 0;
A seal 42 is included.

A hydraulic system 80 for implementing the present invention shown in FIG. 13 includes a hydraulic pump 43 driven by a motor 47, a lift actuator 48, and a tank 44. The operation of supplying or returning pressure oil to the hydraulic cylinder 17 via the port 17a and the line 45a is controlled by an extrusion body release solenoid 45 and an extrusion body return solenoid 46. Similarly, the bypass valve actuator 5 can be controlled by a bypass closing solenoid 50 and a bypass opening solenoid 51. This hydraulic system 80 is prevented from overpressure by a safety valve 52,
Port 17b also prevents vacuum locking.

The flow rate calibrator control circuit shown in FIG. 14 includes a control box 53, a calibrator regulator 56, and a printer 75. Control box 53 is electrically connected to detector 23 and provided seal monitoring means, calibrator regulator 56 and hydraulic system 80. Regulator 56 is electrically connected to detectors 24, 25, continuous flow system 57, and printer 75.

The operation of the small flow meter illustrated in FIGS. 1-14 will be described below with particular reference to FIGS. 1-4. The flow direction in the tester in the launch mode is indicated by the solid arrow in FIG. The fluid enters the inlet tube 1 and then flows through the housing 2. During the verification cycle, fluid is prevented from flowing through the bypass pipe 3 by the normally closed bypass valve 4. The fluid enters the inlet section 6 of the housing 2, passes through the main cylinder 9 and exits the housing 2 through the outlet pipe 11.

From the hydraulic cylinder 17 to the tank 44 as shown below
The verification cycle is initiated by draining the pressure oil. The extruded body 7 is assisted to enter the main cylinder 9 by a compression spring 12, and the fluid is introduced into the inlet 6.
pass through. As the pusher body 7 enters the main cylinder 9, fluid enters the downstream section 10 from the main cylinder 9 as shown in FIG. 2 and is forced out of the housing 2 through the discharge tube 11. Detectors 24 and 25 provide signals when detection flag 21 passes. Optionally, the extruder 7 enters the downstream section 10 after the verification cycle has been completed, as shown in FIG.

By temporarily opening the bypass valve 4 and applying hydraulic pressure to the hydraulic cylinder 17, the extruder 7 is returned to the starting position. In doing so, fluid enters the housing 2 through the outlet pipe 11 and exits through the inlet pipe 1 due to the movement of the extruder 7, as shown in FIG.

For two or three reasons, it is desirable to arrange the discharge pipe 11 on the side of the downstream section 10. When the extruder 7 drains from the main cylinder 9, the pilot 1 of the extruder
3 is engaged in the sleeve bearing 14, and the extruder 7
are aligned axially with the main cylinder 9. Downstream part 1
The evacuation of the fluid from 0 serves as a natural stop mechanism to stop the movement of the extruder 7 and does not require special stop means. However, for high flow rates, it is desirable to have a dartpot control at the point where the pressure oil exits the hydraulic cylinder 17. Moreover, after the extruder 7 enters the downstream part 10,
This extruder cannot prevent fluid outflow from the downstream section 10. This is because the fluid exits radially from the downstream part. Other notable advantages are:
Suspended solids such as sand or gravel that may be present in the fluid have less tendency to adhere to seals 28 and 29 due to the scavenging action of the flowing fluid.

When the extruded body 7 is returned into the introduction part 6, the shaft 8
The journal bearing 15 acts as a guide means. However, it will be readily understood that other guiding means and other extrudate return means may also be used.

The bifurcated structure of the inlet tube 1 allows the fluid to be introduced into the inlet 6 substantially longitudinally, thereby reducing the oblique stress on the extrusion body 7, which reduces the diameter and weight of the hydraulic shaft 8. This is an additional reason why it can be lowered. The lower weight of the shaft 8 increases the life of the seal when the miniature flow meter is operated in a horizontal position. As a result of the reduced diameter of the shaft 8, the pressure drop across the extrusion body 7 is reduced when the extrusion body 7 is placed in the main cylinder 9.

It is desirable to minimize the pressure drop of the fluid flowing past the extrusion body 7 when the extrusion body is placed in the introduction section 6 or the downstream section 10. Therefore, the diameter of the introduction section 6 and the downstream section 10 can be substantially larger than the diameter of the extrusion body 7. The conical shape of the extrusion body 7 helps reduce this pressure differential by reducing turbulence in the fluid flowing along the extrusion body 7.

As the extruded body 7 enters the main cylinder 9,
The extrusion seals 28 and 29 are compressed in contact with the chamfer surface 30 or 31 of the cylinder 9. Such extrusion seals 28 and 29 increase the pressure in the annular space 32 between these seals, resulting in a seal that does not require conventional outer block or extraction pressurization. Another significant advantage is the low pressure drop across the extrudate as it moves inside the main cylinder 9. This is because minimal friction occurs as the seal slides against the inner surface of the main cylinder 9.

Depending on the type of fluid to be calibrated, this miniature flow calibrator can be operated in a horizontal or vertical orientation. FIG. 10 shows an extrusion seal suitable for use in a horizontally operated calibrator. As the extrusion body 7 slides inside the main cylinder 9, the gravitational force acting on the extrusion body 7 tends to pull the extrusion body towards and towards the bottom of the main cylinder 9. If the seal cannot withstand the weight of the extrusion,
Metal-to-metal contact occurs with the undesirable result of damaging the finish of the main cylinder 9. Seals 28 and 29 thus each have a base 34a projecting from retaining ring 36. To extend the life of seals 28 and 29, they can be made of a relatively rigid sealing material such as polytetrafluoroethylene. The use of a relatively stiff seal material allows the seal to be used with fluids of low lubricity. On the other hand, the use of rigid sealing materials is not recommended for fluids with a high content of suspended solids. This is because there is a strong tendency for fluid substances to become embedded within the seal.

For operation of a compact flow meter in a vertical position, seals 28' and 29' shown in FIG. 11 are suitable. Since these seals 28' and 29' do not have to bear the weight of the extrusion body 7, only the lip 74' has to be in contact with the inner surface of the main cylinder 9. These seals 28' and 29' can be made of a relatively resilient material such as VITON. Solid particles entrained by the fluid to be measured are less likely to become embedded in these seals 28' and 29', and when the extrudate 7 enters the inlet 6 or the downstream part 10, the seals has a strong tendency to be removed by fluids flowing along. Seals 28' and 29' are therefore suitable for use with contaminated fluids such as crude oil. However, the soft seal material
Generates high friction when used with low lubricity fluids.

The integrity of extrusion seals 28 and 29 is verified by monitoring the pressure within annular space 32. If there is no pressure drop as the extrusion body 7 moves from one end of the main cylinder 9 to the other, the seal 2
The dynamic integrity of 8 and 29 is verified. A pressure element, such as a transducer, is arranged in the annular space 32 and connected to the detector rod 19 or the shaft 18 of the extruder.
Electronic signals can be sent through wires placed inside. Detecting annular space 32 Rod 19
The annular space 32 is in fluid communication with an externally disposed pressure element or transducer 82 by a channel 58 communicating with a channel 59 in the annular space 32 . Seal monitoring means may also include those disclosed in a pending patent application entitled "Flow Verifier with Seal Monitor" of inventors Helmut W. Hopföh and Herschel Roberson, which has a common assignee and is filed concurrently. can.

A static method of measuring seal integrity consists in placing the extrusion body 7 in the main cylinder 9 with the bypass valve 4 in the open position. In this way, the internal pressure of the annular space 32 can be observed in a static manner over a longer period of time. This method is sometimes preferred because the minimum assay cycle time can be 1/2 second or less.

In embodiments of the invention used for high flow rates, the diameters of the main cylinder 9 and extrusion body 7 can be made considerably larger. In this case, the volume of fluid compressed into the annular space 32 is therefore very large, amounting to several cubic centimeters or more. Therefore, the pressure in the annular space 32 can become excessive. In this state, a volume compensator 37 as shown in FIG. 12 can be provided to allow expansion of the fluid volume. When the fluid in the annular space 32 is compressed, the inner sprung element 39 compresses the spring 40 against the outer element 41. The fluid located between the inner element 37 and the outer element 41 is forced out of the volume compensator 37, with the seal 42 acting as a fluid barrier and the fluid compressed in the annular space 32 being forced into the main cylinder 9. Prevent escape.

During launch and verification modes, the pusher release solenoid 45 shown in FIG. . The extruder release solenoid 45 is closed, the extruder return solenoid 46 is opened, and the hydraulic pump 4 is closed.
The extruded body 7 is returned by filling the hydraulic cylinder 17 with pressure oil pumped from the tank 44 by the pump 3.

The pressure oil pump 43 is driven by a motor 47. The flow rate of the pumped hydraulic oil is determined by a lift selector valve 48, which actuates a lift actuator 49 for controlling the orientation of the calibrator. Bypass valve closing solenoid 5
0. Preferably, a hydraulic system is also used to control the bypass valve by means of a bypass valve opening solenoid 51 and a bypass valve actuator 6.

The control box 53 shown in FIG. 14 makes it possible to carry out a few authorization actions. That is, the signal from bypass valve 4 indicates that the bypass valve is closed, and the signal from bypass valve seal monitor 54 indicates that the bypass valve is closed.
until it shows that the pressure inside is higher than the line pressure.
Preventing the extrusion body 7 from starting. Also, before closing the bypass valve 4, it is necessary for the detector 23 to indicate that the extrusion body 7 is in the introduction part 6.

As the extrusion body 7 advances through the main cylinder 9, the detector flag 21 passes the detector 24;
This detector 24 provides a signal to an calibrator regulator 56. Upon receiving this signal, regulator 56 generates a series of high frequency digital pulses within it;
This pulse is transmitted by the detector flag 21 to the detector 25.
It is counted until it passes through. For greater accuracy, the regulator 56 measures fractional pulses using a dual chromometry method well known in the art, but may also use other known methods, such as a four-counter method or a phase-locked loop method. can do.

The amount of fluid forced out is determined from the distance between the detectors 24 and 25 and the diameter of the main cylinder 9 corrected for expansion due to pressure and temperature.
Since the detectors 24, 25, and 26 are mounted on a shaft 22 made of a material with a low coefficient of thermal expansion such as Invar, the distance measured between the detectors 24 and 25 is independent of temperature or pressure. No modifications are required. From the elapsed time and the volume thus determined, the flow rate can be calculated. The flow rate is then compared to the output generated from continuous flow meter 57.

Seal monitoring means on pusher 7, hydraulic shaft 8, and sensing rod 19 provide signals verifying seal integrity or indicating measurement errors due to fluid leakage through any of these seals. If desired, regulator 56 can be equipped with a printer 58 for producing hard copies of the data and calculations.

As shown in FIG.
By using a drain tube 101 extending radially outwardly from 06, the miniature flow meter of the present invention can be operated with relatively high and relatively low fluid pressures. In this case, the fluid is introduced into the housing 2 radially rather than longitudinally. Spring 1 used to stop the movement of the extrusion body 7 in the embodiment of FIGS. 1 to 4
2 can be omitted, and the sleeve bearing 14
A coil spring 112 can be arranged concentrically around the .

As shown in FIG. 15, the cylinder 17 and shaft 8
A pressure tank 120 and ram 122 can be used instead. Pressure tank 120 by supplying or discharging fluid through port 17a
The position of the extruded body 7 can be adjusted by adjusting the pressure inside.

This flow rate tester is mounted on a hinge 2 on a rack 200.
It is rotatably mounted by 02. When the left actuator 49 is actuated, the flow meter rotates about the hinge 202 from a horizontal position to a vertical position, with the bottom 204 resting on the stop 206.
The calibrator can then be returned to the horizontal position.

The embodiment illustrated in FIG.
It is activated by draining fluid from 01a. With this construction, at the beginning of the verification cycle, the extrusion body 7 is forced into the main cylinder 9 by the pressure differential acting on the extrusion body 7 as well as the liquid flow through the compression spring 112 and the inlet tube 110. Ru.

More specifically, because of the pressure isolation area due to the cross-sectional area of the ram 122 and rod 19 extending into the housing 2, the effective area of the downstream face of the extrusion body 7 is smaller than the effective area of the upstream face. Thus, due to the interposition of the rod 19 and the ram 122, the total pressure acting on the downstream face of the extrusion body 7 is reduced below the pressure acting on the larger effective area of the upstream face of the extrusion body 7. If the fluid pressure is high, this becomes an important factor for forcing the extrusion body 7 into the cylinder 9.

When the extrusion body 7 returns from the downstream section 106 to the introduction section 110, the extrusion body pilot 13 engages in the axial sleeve bearing. Extruded body pilot 1
3 and the sleeve bearing 14 are connected to the introduction guide member 1 for holding the extrusion body 7 in axial alignment with the main cylinder 9.
10a. This guide member 110a
This allows the extruded body 7 to smoothly move in and out between the introduction part 110 and the main cylinder 9. spring 11
2 is particularly effective for feeding the extruded body 7 into the cylinder 9 during low-pressure operation. Similarly, the journal bearing 15 acts with the ram 122 and the rod 19 to form a downstream guide member.

For operation at ultra-high pressure, a pressure tank 120
It is desirable to balance the differential pressure acting on the extrusion body 7 by limiting the amount of drainage from the solenoid 45 into the solenoid 45. As shown in FIG. 16, a valve 208 is placed on rack 200 and connected to port 17a via fluid line 210.
Valve 208 includes a cylindrical housing 212 having a sliding pin 214 pivotally supported at one end and a sliding piston 215 at the other end. The pin 214 is inserted into the hole 2 so that its tip 217 contacts the piston 215.
It slides freely inside the 18. Pin 214 communicates at its upper end 220 with downstream section 106 via fluid line 222 . Piston 215 includes an annular sealing surface 224 that is pressed against a valve seat 226 in line 210 . The sealing surface 224 and the piston 215 are surrounded by an annular chamber 228, which is connected to the tank 44 via a line 45a. Piston 21
The upper end 229 of 5 communicates with an enlarged fluid chamber 230.

Fluid is transferred to line 210 under control of regulator 56.
to chamber 230, or chamber 230
selectively from solenoid 2 to annular chamber 228.
Guided by 32. fluid into the housing 212
When the piston 215 is introduced into the valve seat 226, the piston 215 is pressed against the valve seat 226 and the line 210 is closed. Housing 212
Directing fluid from line 210 to chamber 228 causes fluid to flow along piston 215 from line 210 and is controlled by the pressure within downstream section 106 .

In this way, fluid pressure can be maintained by blocking the evacuation of fluid from pressure tank 120 as necessary to compensate for any imbalance in the pressure applied to extrusion body 7 during the calibration cycle, or to control fluid pressure. extraction can be carried out. Such unbalanced pressure is a function of line pressure and is caused by the difference in area between the downstream and upstream surfaces of the extrusion body 7 due to the arrangement of the ram 122 and rod 19.

Such compensation is achieved by arranging pin 214 and piston 215 to model the ratio of the total area displaced downstream of the extrusion to the end surface area of ram 122 or, if piston 16 is used. This is done automatically by dimensioning. That is, compensation is automatically performed by sizing each component to satisfy the following equation.

A1/A2=A3/A4 where: “A1” is the cross-sectional area of the piston 215, “A2” is the cross-sectional area of the pin 214, “A3” is the total area displaced at the downstream face of the extruder 7, implementation of the attached figure. In the embodiment, this is equal to the cross-sectional area of the ram 122 (or of the piston shaft 8 in the embodiment of FIG. 1) plus the cross-sectional area of the rod 19, and "A4" is the cross-sectional area of the end face of the ram 122, or if the piston 16 is used, A4 is the end surface area of this piston 16.

If the valve 208 is configured according to the above relational expression,
Line pressure in the calibrator is automatically compensated. More importantly, this compensation is essentially instantaneous. Considering that the verification cycle is on the order of a second or less, rapid compensation of unbalanced pressures is imperative.

The rest of the operation of the verification cycle of the embodiment of FIG. 15 is generally similar to that described for the embodiment of FIGS. 1-4.

The flow rate tester 310 shown in FIG. 17 includes an extrusion body housing 312, a piston-like extrusion body 314,
Bypass pipe 316 and relatively rigid detection rod 3
18 and a double-acting cylinder 320. Bypass tube 316 is connected to inlet tube 32 with inlet port 324
2, and a drain 326 with a drain port 328;
A bypass valve 330 is disposed between the inlet pipe 322 and the outlet pipe 326 and is normally closed. Liquid from piping or the like (not shown) is introduced into the calibrator 310 through the inlet port 324 and returned to the piping or other system through the exhaust port 328.

Cylinder 320 is typically a hydraulic cylinder, and
The extrusion housing 3 through a suitable seal 336
12 includes a double acting piston 332 having a piston rod 334 inserted therein. More specifically, a distal end 338 of piston rod 334 is secured to extrusion 314. Therefore, when pressure oil is moved into and out of the cylinder 326 by the action of the hydraulic system 321, the piston 332 is moved, so that
A corresponding movement of the extrusion body 314 occurs. However, in place of cylinder 320 and piston 332, a pressure tank and hydraulic ram (not shown) can be used if desired.

The detection rod 318 is connected to the extrusion housing 312.
through a seal 340 of the housing 312 from its inner end 342 secured to the extrusion 314.
It slidably extends to an outer end 344 on the exterior of the. In this manner, reciprocating movement of pusher 314 within housing 312 results in telescopic movement of rod 318 relative to seal 340. A position detector 343 is arranged along the rod 318. This detector 343 may take any conventional form, but is conveniently an optical or magnetic position sensing means, such as a flag or other indicator 343 located along the rod 318.
45 is sensed by a suitable sensing element 347 located on rod 349 adjacent to rod 318. In this way, the detection rod 31 relative to the housing 312 is controlled by the electrical unit 323, which includes a computer and an electronic timer.
8 can be quantified and the position of extrusion 314 relative to housing 312 can be monitored.

The extruder housing 312 includes a pair of enlarged chambers 346, 348 at each end of the cylinder 350. Chamber 348 communicates with exhaust tube 326 and chamber 346 communicates with inlet tube 322. These chambers 346 and 348 have sufficient internal dimensions to allow fluid to flow unimpeded around the extrusion body 314 when the extrusion body 314 is disposed therein. The extruded body 314 has elastic annular seals 352 and 354 on its outer periphery;
These seals are compressed when pusher body 314 is placed within cylinder 350 as shown in FIG. Such compression may occur in cylinders 3 adjacent to respective chambers 348 and 346.
This is implemented by chamfer surfaces 356 and 358 provided at each end of 50. Seals 352 and 35
4 are engaged with cylinder 350, an annular space 360 is defined between these seals, extrusion body 314, and cylinder 350. This space 360 communicates with the interior of rod 318 by a radial passageway 362.

Seals 352 and 35 as shown in FIG.
4 has a U-shape and is arranged so that its inward protrusion 351 is bent by the inner surface of the cylinder 350. Inside each seal 352 and 354 is a U
A shaped metal spring member 353 is held between an annular band 355, and this annular band 355 is held between an upright column 357 of the extruded body. Seals 352 and 354 are also mounted on screws 36 on extrusion 314.
The guide member 359 held by the guide member 359 is removably arranged.

The extruded body 314 is pushed into the cylinder 350 by a coil spring 371. This spring 371 is connected to the flexible bearing sleeve 37 in the chamber 346.
It surrounds 5. Sleeve 375 receives tapered protruding pilot portion 373 to guide piston rod 334 within chamber 346;
are formed to be aligned in the axial direction.

Although the present invention has been described with respect to particular configurations of extrusion 314, housing 312, and bypass tube 316, those skilled in the art will appreciate that the present invention may be applied to a variety of flow meter configurations, including those previously described. will understand.

Detector rod 318 includes a first relatively rigid tube 346 defined therein and a second relatively rigid tube 366 held concentrically within the first tube. The first tube 364 is connected to the inner wall of the rod 318,
It is defined by the outer wall of second tube 366 and seals 368 at each end of rod 318. While the first tube 364 is sealed at both ends, the second tube 366 is open at its innermost end 370 and communicates with the interior of the housing 312 and preferably with the upstream side of the extrusion body 314. do. At the midpoint of its length, the first tube 364 communicates with the passage 362 via a passage 365, which communicates with the space 360 of the seal. An outer end 372 of the second tube 366 communicates with a pressure sensor 374 mounted on the sensing rod 318, and an outer end 375 of the first tube 364 communicates with the passageway 376.
The passageway 376 communicates with the transducer 374 via a tube 377. Now the 19th
Referring to the figures, transducer 374 is a differential pressure sensor, with its low pressure port 378 communicating with second tube 366 and its high pressure port 380 communicating with first tube 366.
It communicates with pipe 364 .

Sensor 374 includes an externally mounted, generally circular, rotating indicator 382 having a pie-shaped cutout 384 cut out therein. A position sensor 386 is mounted above the cylinder 320 as shown in FIGS. 17, 19 and 20.
is mounted, and the position sensor 386 detects the rotational position of the indicator 382 in alignment with the position of the pressure sensor 374 at the end of the verification cycle. Position sensor 386 can take various forms, such as an optical or magnetic position sensor or a linear transducer. If an optical system is used, as in the illustrated embodiment, a mutually opposing light source 391 and photoreceptor 395 are included in a U-shaped housing 393 that straddles the display 382, as shown in FIG. It will be done. Alternatively, sensor 374 can be configured to provide a continuous electrical signal relative to the differential pressure sensed.

As shown in FIG. 19, pressure sensor 374 includes a tubular body 388 that extends through axial bore 38.
9, magnetic piston 390, piston seal 39
2, range spring 394, and cylindrical rotating magnet 3
96. Attachment members 398 and 400 are threaded onto opposite ends of axial bore 389 and provide narrow passages 402 within these members. The magnetic piston 390 includes a magnet 404 and a tip-shaped piston element 4 configured to slide along the bore 389.
06. Spring 394 is retained within piston element 406 between a pair of stacked spacers 408 and mounting member 400 . As the pressure differential between ports 378 and 380 causes magnet 404 to move along hole 389, rotating magnet 396 held within transverse hole 410 is rotated. This rotation rotates display 382 approximately 180 degrees and places it in the position shown in FIG.

Sensor 374 can be made by modifying a piston-type sensor sold by Orange Research, Milford, CT. However, it will be readily appreciated that other types of differential pressure sensors may also be used, such as rotary diaphragm sensors or composition diaphragm sensors available from Orange Research.

When the small flow rate calibrator 310 is operated, when a fluid whose flow rate is to be measured flows into the calibrator 310, the extruder 314 moves between two predetermined positions in the cylinder 350, and in order to move this distance, The required time is determined by electrical unit 323. To explain in more detail, the introduction port 32
4 causes the extruder 314 to move from the right side to the left side in FIG. 1, from chamber 346 to chamber 348. This results in
A detection rod 318 further emerges from the housing 312. A position sensing element 347 arranged along the sensing rod 318 detects the initial and final position of this rod, and these indications are displayed on the electrical unit 323.
is used to control an electronic counter (not shown) in the . The flow rate can be calculated based on the time it takes the extruder 314 to travel a predetermined length.

A normally closed poppet valve 330 is used to switch the calibrator 310 between measurement mode and retraction mode.
and cylinder 320 are used. More specifically, when the poppet valve 330 is in its open position, pressure oil is supplied to the cylinder 320;
The extruded body 314 is moved from the chamber 348 to the chamber 34.
Return to 6. The positions of piston 332 and poppet valve 330 are controlled by hydraulic system 321.

As extrusion body 314 enters cylinder 350, extrusion body seals 352 and 354 close to cylinder 35.
0 chamfer surfaces 356 and 358. If the integrity of these seals 352 and 354 is intact, the pressure within space 360 will increase as these seals are compressed. Because this annular space 360 is in fluid communication with the high pressure port 380 of the differential pressure sensor 374, the magnetic piston 390 moves to compress the range spring 394. This movement of piston 390 causes rotating magnet 396 and indicator 382 to rotate. Movement of indicator 382 is then detected by its position sensor 386 and seals 352 and 3
54 is operating. When extruder 314 is placed in chamber 346 or 348, or if there is a leaky seal, the differential pressure will be zero and indicator 382 will not be moved. When the differential pressure is equalized, the spring 394
Return 0 to its initial position. Therefore, the notch 38 of the display
4 is placed on the upper side, and the light emitted from the light source 391 is detected by the photoreceptor 395.

For optimum reliability, the indicator position sensor 386 should rotate the rotating indicator 382 in a position corresponding to the end of the verification cycle as shown in FIG.
arranged to detect. In this way,
Any seal failure during any verification cycle will cause position sensor 389 to indicate rotation indicator 3 at the insertion point of detection rod 318 corresponding to the end of the verification cycle.
This is displayed by failing to detect the presence of 82. However, in a few uses, it may be necessary to further increase the reliability of this meaning. In these applications, indicator 382 and sensor 386 can be replaced with a continuous indicator that provides a continuous electrical output to indicate seal integrity. This can be accomplished in a variety of ways, such as by mounting position sensor 386 on detection rod 318 or pressure sensor 374.

A static method of verifying seal integrity is to place extrusion body 314 inside cylinder 350 with bypass valve 330 open. In that case, the pressure in the annular space 360 can be observed over time. Certification cycle time is 1/
This method is also effective because it takes less than 3 seconds.

Although in the illustrated embodiment, the pressure downstream of extrusion 314 is compared to the pressure between seals 352 and 354, it is also useful to measure the pressure upstream. Also, while a concentric arrangement of conduits 364 and 366 is preferred, a pair of separate parallel conduits could be used. Additionally, while a rotary indicator 382 is believed to be preferred, a variety of other indicators 382 and position detectors may be used.

The seal integrity monitoring means of the present invention has many advantages. This seal monitoring means has a small number of moving parts. Conduits 364, 366 can be made of a rigid material that is not susceptible to crushing or breaking. By locating the differential pressure measuring means directly at the free end of the conduit, the seal monitoring means can be completely self-contained. In that case, the seal monitoring means can move together with the seal to be monitored. At the same time, the differential pressure measuring means is accessible from the outside of the compact flow meter and can be easily maintained without disassembling the meter or removing the extrusion. This seal monitoring means can be completely self-contained and does not require a double block/bleed system on an external pressure source.

[Brief explanation of drawings]

FIG. 1 is a partial longitudinal sectional view of the small flow rate calibrator according to the present invention at the starting position, FIG. 2 is a partial longitudinal sectional view of the small flow rate calibrator during the verification cycle, and FIG. 3 is a partial longitudinal sectional view of the small flow calibrator during the verification cycle. FIG. 4 is a partial longitudinal sectional view of the compact flow rate tester in extruder return mode; FIG. 5 is an enlarged vertical sectional view of the bypass valve shown in FIG. 1; FIG. 7 is an enlarged partial cross-sectional view of the downstream guide means shown in FIG. 1; and FIG. 8 is an end view taken along lines 6-6 of FIGS. 9 is a side view of the embodiment of the extrusion taken along line 9--9 of FIG. 8; FIG. 10 is an illustration of the implementation of the extrusion seal shown in FIG. 11 is a partial longitudinal sectional view of an embodiment of the extrusion seal; FIG. 12 is an enlarged side view of the volume compensator shown in FIG. 8; and FIG. 13 is a flow rate diagram of the present invention. A block diagram of a suitable hydraulic system for operating the calibrator, FIG. 14 is a block diagram of an embodiment of the control system used in the flow rate calibrator of the present invention, and FIG. 15 is a block diagram of an embodiment of the control system used in the flow rate calibrator of the present invention. A vertical cross-sectional view of another embodiment at the starting position, FIG. 16 is an enlarged vertical cross-sectional view of an ultra-high pressure control valve used in the embodiment shown in FIG. 15, and FIG. 17 is a small flow rate tester of the present invention. FIG. 18 is a partially enlarged sectional view showing a portion including the extrusion seal of FIG. 17;
Figure 19 is an enlarged cross-sectional view of the pressure sensor provided at the end of the detection rod in Figure 17, and Figure 20 is the
FIG. 3 is a cross-sectional view taken along line 30-30 in the figure. DESCRIPTION OF SYMBOLS 1... Introduction pipe, 2... Housing, 3... Bypass pipe, 4... Bypass valve, 5... Actuator, 6... Introducing part, 7... Extruded body, 8... Shaft (piston rod), 9... ...Main cylinder, 10...Downstream section, 12...Spring, 13...Pilot, 14
... Bearing journal, 15 ... Journal, 16
...Piston, 17...Hydraulic cylinder, 19...
Detection rod, 20... Journal, 21... Detection flag, 22... Detection unit, 23, 24,
25... Accuracy detector, 28, 29... Extruded body seal, 32... Space, 37... Volume compensator, 6
0... Poppet valve, 61, 62... Flange, 6
3... Actuator, 64, 65... Seal,
66...Space, 67...Channel, 101
...Discharge pipe, 111...Introduction pipe, 110...Introduction part, 112...Compression spring, 120...Pressure tank (casing), 122...Ram, 200...Rack, 202...Hinge, 208... Valve, 215...
... Valve piston, 214 ... Pin, 310 ... Small flow rate tester, 350 ... Cylinder, 314 ... Extrusion body, 345 ... Position sensor, 352, 354 ...
...Seal, 360...Space, 364...1st
Conduit, 366...Second conduit, 374...Differential pressure sensor, 390...Magnetic piston, 388...Housing, 396...Rotating magnet, 382...Display disk, 391...Light source, 395...Photoreceptor.

Claims (1)

[Scope of Claims] 1 (a) a fluid introduction tube; (b) a housing including: () a main cylinder having a substantially uniform inner diameter and an inlet end and a downstream end; () said main cylinder; () an inlet having an inner diameter greater than an inner diameter of the main cylinder and in fluid communication with the inlet tube and the inlet end of the main cylinder; a downstream portion in fluid communication with the end; (c) a discharge tube in fluid communication with the downstream portion; and (d) an extrusion body movably disposed within the housing, the extrusion member having an upstream surface and a downstream surface. (e) a sealing means for forming a fluid barrier between an inlet end and a downstream end of the cylinder when the extrusion body is disposed within the main cylinder; (f) introducing section guide means for restricting radial movement of the extrusion body when the extrusion body is disposed in the introduction section; (f) when the extrusion body is disposed in the downstream section; (g) means for detecting the longitudinal position of the extrusion in position within the housing; and (h) downstream guide means for restricting radial movement of the extrusion when the extrusion is (i) a bypass tube in fluid communication with the inlet tube and the outlet tube; and (j) an calibrator disposed in the bypass tube in an extrudate return mode. and a bypass valve that is opened to place the calibrator in a calibration mode or closed to place the calibrator in a calibration mode. 2. said inlet tube guiding means () being axially connected to said upstream face of said extrusion body and having a diameter sufficient to project beyond said inlet tube when said extrusion body is disposed within said downstream section; a shaft having a length; and () a journal bearing disposed in the introduction portion so as to be axially aligned with the shaft and slidably engage the shaft. The small flow rate tester described in item 1. 3. The extruded body return means includes: () a hydraulic cylinder disposed coaxially with the shaft and having a substantially uniform inner diameter; () coaxially connected with the shaft and movably disposed inside the hydraulic cylinder; 2. The compact flow rate tester according to claim 1, further comprising: a hydraulic piston disposed therein; and () a hydraulic source that pressurizes the hydraulic cylinder to return the extrusion body. 4. The downstream guide means includes: () an extrusion pilot extending axially from a downstream surface of the extrusion; and () an axial sleeve disposed within the downstream portion and axially aligned with the extrusion pilot. Claim 1 characterized in that it includes
Compact flow rate tester described in section. 5. The small flow rate tester according to claim 1, wherein the main cylinder has a substantially uniform inner diameter and is chamfered at an inlet end and a downstream end. (b) a housing comprising: () a main cylinder having a substantially uniform inner diameter; () having an inner diameter greater than the inner diameter of said main cylinder; an inlet end in fluid communication with an inlet end of the main cylinder; () a downstream end having an inner diameter greater than an inner diameter of the main cylinder and in fluid communication with a downstream end of the main cylinder; (c) a downstream end in fluid communication with the downstream end; (d) an extrusion body movably disposed within the housing, the upstream face, the downstream face and the inlet when the extrusion body is disposed within the main cylinder; an extrusion body having a sealing means for forming a fluid barrier between an end and a downstream end; (e) means for detecting the longitudinal position of the extrusion body in a predetermined position in the housing; (f) means for returning the extrudate from the downstream section to the inlet; (g) a bypass tube in fluid communication with the inlet tube and the outlet tube; (h) a means for returning the extrudate from the downstream section to the inlet section; a bypass valve that is opened to place the device in a return mode or closed to place the calibrator in a verification mode; extrusion launching means including means, the high pressure generating means including a shaft axially connected to a downstream face of the extrusion, the shaft being arranged such that the extrusion is disposed within the introduction section. extruded body launching means for promoting movement of the extruded body from the introduction part into the main cylinder when a fluid having a length sufficient to extend beyond the downstream part flows in when the extruded body is (j) an introductory section guide means comprising: a shaft axially coupled to and having a length sufficient to protrude beyond the introduction section when the extrusion body is disposed within the downstream section; and () disposed within the introduction section; , a miniature flow rate tester having a journal bearing axially aligned with and slidably engaged with the shaft. 7. The means for returning the extruded body from the downstream section to the introduction section comprises: (a) a casing arranged axially with respect to the shaft and having a substantially uniform inner diameter; and (b) axially with respect to the shaft. and (c) a hydraulic source for returning the double acting member by pressurizing the casing. A small flow rate tester according to claim 6. 8 a second tube extending axially inside the cylinder;
8. The compact flow rate tester according to claim 7, further comprising a shaft, the second shaft including means for measuring the position of the extruded body. 9. The small flow rate tester according to claim 6, wherein means for measuring the position of the extruded body is attached to the shaft. 10. A miniature flow rate tester as claimed in claim 9, including means provided within the shaft for monitoring the integrity of the sealing means of the extrusion. 11. A compact flow rate calibrator according to claim 7, characterized in that it includes means for compensating the high pressure on the downstream surface during the calibration cycle. 12. Claim 12, wherein said compensating means includes a valve configured to selectively retain fluid within said hydraulic cylinder or to regulate fluid flow from said hydraulic cylinder. The small flow rate tester according to item 11. 13. The small flow rate tester according to claim 6, wherein the tester is mounted so as to pivot between a horizontal position and a vertical position. 14. a cylinder having a substantially uniform inner diameter and a fluid inlet and a fluid outlet; a piston movable within said cylinder as a fluid barrier; means for detecting movement of said piston along said cylinder; a casing; a fluid actuator including a member double-acting within the casing at one end and coupled to the piston at the other end; a fluid source for delivering fluid into and out of the casing; and controlling fluid flow from the casing. a valve for controlling fluid flow from the casing, the valve engaging the valve piston at one end and in fluid communication with the interior of the cylinder at the other end. said valve piston and said pin being dimensioned to control fluid flow from said casing to a flow rate that produces a pressure on said member that substantially equalizes the pressure exerted on opposite sides of said piston. A small flow rate calibrator that has been determined. 15 The ratio of the cross-sectional area of the valve piston to the cross-sectional area of the pin is equal to: the cross-sectional area of the member plus the cross-sectional area of another element connected to the piston and extending parallel to the member inside the cylinder; 15. A compact flow rate tester according to claim 14, characterized in that the ratio is substantially equal to the cross-sectional area of the free end of the member. 16 a measuring cylinder having a substantially uniform inner diameter and filled with the fluid whose flow rate is to be measured during operation; and an extrusion body movably disposed inside said cylinder, forming a fluid barrier inside said cylinder. first and second sealing means,
the sealing means being compressible and forming an annular volume of compressed fluid defined by the sealing means, the extrusion and the cylinder; a first end secured to the extrusion; a first conduit in communication with the annular volume and having a second end accessible from outside the cylinder; a first conduit having a first end secured to the extrusion and in communication with the fluid in the cylinder; a second conduit having a second end accessible from outside the cylinder; and a second conduit disposed outside the cylinder for measuring a differential pressure between the second ends of the first conduit and the second conduit. A small flow rate tester including a means for determining the flow rate. 17. A miniature flow meter according to claim 16, characterized in that one of said conduits is arranged concentrically within the other, and said measuring means is mounted on said conduit. . 18 The measuring means includes a magnetic piston and a housing, the magnetic piston is movable inside the housing, the housing includes a magnet movable by movement of the magnetic piston in the housing, and the magnet 18. The small flow rate tester according to claim 17, wherein the device has a display portion outside the housing, and further, the measuring means includes position sensing means for detecting movement of the display portion. . 19. A compact flow rate tester according to claim 18, characterized in that the position sensing means is configured to be activated at the end of the stroke of the extruder. 20 Claim 18, wherein the display means is a disk having a cut-out portion.
Compact flow rate tester described in section. 21. The small flow rate tester according to claim 18, wherein the position sensing means includes an optical position sensor. 22. Claim 17, characterized in that it includes means disposed outside the cylinder for detecting the position of the extrusion body by detecting the position of the first conduit and the second conduit. Compact flow rate tester described in section. 23. The flow rate tester according to claim 17, wherein the measuring means includes a differential pressure sensor. 24. The miniature flow assay of claim 17, wherein the outer conduit is rigid and the housing includes sealing means for sealing the portion of the outer conduit that projects from the housing. vessel. 25. The miniature flow meter of claim 24, wherein the conduit is relatively rigid and configured to be telescopically inserted through the housing.