GB2155136A - Fluid flow device-coupling thereto - Google Patents

Abstract

A fluid flow device (1) comprising a fluid passageway (11, 10, 9, 4, 4a) adapted to receive a fluid receiving member, at least one retaining formation (3b) for retaining the fluid receiving member in the passageway. The retaining formation is movable into and out of engagement with the fluid receiving member. Clamping means (7, 25) clamps the retaining formation in engagement with the fluid receiving member. <IMAGE>

Description

SPECIFICATION Fluid flow device This invention relates to a fluid flow device.

Known fluid flow devices have a number of different forms. For example in pressure testing apparatus it is known to provide a fluid flow device for connection to a fluid receiving member of a pressure gauge to be tested. Typically the fluid flow device and the fluid receiving member are each provided with a screw-thread, and the fluid receiving member is connected to the fluid flow device by screwing the fluid receiving member into the fluid flow device. This is an extremely time consuming operation.

According to one aspect of the invention there is provided a fluid flow device comprising a fluid passageway adapted to receive a fluid receiving member, at least one retaining formation adapted to retain the fluid receiving member in said passageway, the or each retaining formation being movable into and out of engagement with the fluid receiving member, and clamping means for clamping the or each formation in engagement with the fluid receiving member.

Advantageously the retaining formation serves to provide a seal against fluid flow between the fluid passageway and an outer surface of the fluid receiving member. To this end the formation may advantageously comprise a screw- thread.

Preferably the fluid flow device includes a generally annular member. Preferably also the screwthread is disposed on the inner surface of the annular member.

Desirably the annular member comprises two portions movable relative to one another into and out of engagement with the fluid receiving member.

In one embodiment the two portions may be pivotally connected so that they can move pivotally relative to one another.

In another embodiment the two portions are movable linearly relative to one another. In this embodiment one of the portions may be provided with an elongate slot and the other portion may be provided with a guide member which is received in, and guided by, the slot.

Desirably the outer surface of the fluid-receiving member is provided with a screw-thread for engagement with the screw-thread of the fluid flow device.

It is preferable that the fluid flow device comprises a pressure testing apparatus which is adapted to operate at very high fluid pressures.

The fluid-receiving member may be part of a pressure gauge to be tested or calibrated by the testing apparatus.

It is desirable that the fluid flow device further includes an inlet, and a valve element biased against a valve seat by the fluid pressure at the inlet to prevent fluid flow through the fluid passageway to the fluid receiving member.

The fluid flow device preferably includes valve actuating means, said valve actuating means serving to move the valve element off the valve seat when the fluid receiving member is received in the fluid passageway. When the valve element is off the seat, fluid can flow through the fluid passageway to the fluid receiving member. The valve actuating means preferably comprises an actuating member diposed within the fluid passageway and biasing means for biasing the actuating member in a position such that the valve is held on the valve seat. The valve actuating means may also include a valve stem connected between the actuating member and the valve element.

According to another aspect of the invention there is provided a fluid flow device having an inlet, an outlet, a valve element biased against a seat by the fluid pressure at the inlet to prevent flow through the device to the outlet, means for engaging with a fluid-receiving member, in use, said means positioning the member so that it holds the valve element off the seat to receive fluid from the outlet.

Preferably the fluid flow device includes the features of the fluid flow device as described above.

The present invention provides a fluid flow device to which a fluid-receiving member can be attached and detached much more rapidly than has previously been possible. For rexample, the fluid receiving member and fluid flow device can be secured to one another without the need for rotating the fluid receiving member relative to the fluid flow device. This would previously have been necessary when the fluid flow device and fluid receiving member are secured by a screw-thread.

M#reover, the invention achieves this without leakage.

Reference is now made to the accompanying drawings, in which: Figure 1 is a cross-sectional view of one embodiment of fluid flow device according to the invention; and Figure 2 is a cross-sectional view of another embodiment of fluid flow device according to the invention.

In Figure 1 a fluid flow device for pressure testing is generally designated 1 and comprises a body 2 to which an annular member 3 is rigidly attached.

The annular member 3 has an inner surface 3a which defines a chamber 4 within which the uppermost part of the body 2 is disposed. The chamber 4 forms part of a fluid passageway extending through the fluid flow device 1. A valve actuating member in the form of a piston 5 is located in the chamber 4 above the body 2, the piston being movable, along the longitudinal axis A of the fluid flow device, within the chamber.

The chamber 4 and piston 5 are of substantially circular cross-section, and the piston is an interference fit with the chamber by means of an O-ring seal 28.

An uppermost portion 4a of the chamber is of reduced diameter, which diameter is less than the diameter of the piston 5 so that the piston cannot move into this portion. The part of the inner surface 3a of the annular member 3, which defines the portion 4a of the chamber 4 is provided with a screw-thread 3b.

The uppermost part of the annular member 3 is split into two portions 3c, 3d about a plane parallel with the axis A. The portions 3c and 3d are connected by a hinge 6, by means of which hinge the portions 3c and 3d can pivot relative to one another about an axis parallel to the axis A.

The portion 3d is movable with respect to the portion 3c and with respect to the body 2.

Clamping means including a clamp lever 7 is pivotally attached to the end of the portion 3d remote from the hinge 6; the clamp lever can pivot about an axis perpendicular to the axis A, and a knob 7a is provided at the end of the clamp lever.

The end of the portion 3c remote from the hinge 6 is provided with a recess 8 through with the clamp lever 7 can pass.

Within the body 2, the fluid passageway includes longitudinal channelling which is parallel to the axis A. The channelling includes an uppermost channel 9, an intermediate channel 10, and a lowermost channel 11. The channels, 9, 10 and 11 are of substantially circular cross-section: the diameter of the uppermost channel 9 is greater than the diameter of the lowermost channel 11; and the diameter of the lowermost channel 11 is greater than the diameter of the intermediate channel 10.

The valve actuating means also includes a valve stem 12 which is arranged so that it passes through the intermediate channel 10 and the uppermost channel 9, and is attached at its uppermost end to a bolt 13 which is attached to a lowermost surface 5a of the piston 5. The lowermost end of the valve stem 12 is rigidly attached to a valve element 14 which is disposed in the lowermost channel 11.

The lowermost channel 11 is provided adjacent the intermeidate channel 10 with a valve seat 11a against which the valve element 14 can rest. In Figures 1 and 2 the valve element 14 is shown resting against the valve seat 11a. Downward movement of the piston 5 would cause a corresponding downward movement of the valve element 14, so that would no longer rest against the seat 1 lea.

Within the piston 5 a channel 15 is provided which is parallel to the axis A. The channel 15 is of substantially circular cross-section and a top portion 15a of the channel 15 is of larger diameter for receiving an inlet of a fluid-receiving member of a pressure gauge (not shown).

The lowermost portion of channel 15 is sealed by the bolt 13 which screws into the channel 15. A further channel 16 of substantially circular crosssection is provided between channel 15 and the lowermost surface 5a of the piston 5; the channel 16 is arranged at an angle to the axis A.

A fluid medium can flow through the fluid passageway from the lowermost channel 11 to the portion 15a of channel 15, through the intermediate channel 10, through the uppermost channel 9, to the channel 16, and from the channel 16 to the channel 15. The fluid can then flow from the channel 15 to the fluid-receiving member. Clearly this flow is not possible when the valve element 14 engages the seat lia.

A spring 17 is provided in the uppermost channel 9, one end of which abuts against a surface 9a of the uppermost channel. The other end of the spring 17 abuts against the lowermost surface 5a of the piston 5. The spring 17 serves as a biasing means to keep the piston 5 spaced from the body 2, and hence to keep the valve element 14 resting on the seat 11a.

In the pressure testing apparatus shown in Figure 2, the parts which correspond to the parts shown in Figure 1 are designated with the same reference numerals.

In Figure 2 an annular member 18 is provided with a portion 18a movable with respect to the rest of the annular member and with respect to the body 2, along an axis perpendicular to the axis A.

The annular member 18 is provided with an elongate slot 19 with which a guide member 20 attached to the movable portion 18a engages, and along which the guide member can slide. The slot 19 is arranged along an axis perpendicular to the axis A, so that movement is restricted to that direction.

A biasing member 21 is pivotally mounted to a mounting 21a by a pivot 22 which enables pivotal movement relative to the annular member 18 about an axis perpendicular to axis A. The mounting 21a is secured to the annular member 18. The biasing member 21 is biased outwardly from the annular member 18 by a spring 23. The uppermost part of the biasing member 21 extends into a recess 24 provided in the movable portion 18a.

Clamping means in the form of a handle 25 is pivotally attached to the movable portion 18a by a pivot 26 which permits pivoting about an axis perpendicular to the axis A. The end of the handle 25 attached to the pivot 26 is provided with a cam 27 which engages a surface of the movable portion 18a. Movement of the handle 25 about the pivot 26 causes rotation of the cam 27 which in turn causes movement of the guide member 20 along the slot 19; this causes the movable portion 18a to move towards the rest of the annular member 18.

In the devices shown in the drawings the O-rings 28 are provided between the annular member 3 and 18, and the body 2 and piston 5.

The operation of the pressure testing device shown in Figure 1 will now be described.

The inlet of the fluid-receiving member of the pressure gauge is inserted into the portion 15a of channel 15 and pressed downwardly along an axis parallel to the axis A, thereby causing downward movement of the piston 5. This movement is continued until the lowermost surface 5a of the piston 5 comes into contact with the body 2.

The clamp lever 7 is then rotated about its pivotal axis until it lies in a plane substantially perpendicular to the axis A. The portion 3d can then be rotated about the hinge 6 until the portions 3c and 3d come into contact. During this motion the clamp lever 7 passes through the recess 8, and when the portions 3c and 3d are in contact the clamp lever 7 has completely passed through the recess 8 and can be pivoted about its pivotal axis until it again lies along an axis parallel to the axis A. The portions 3c and 3d are now clamped together, and the screw-thread 3b engages a screwthread provided on the external surface of the fluid-receiving member, thereby holding the pressure gauge in position on the testing device, and providing an effective seal against fluid flow between the screw-thread 3b and the external surface of the fluid receiving member.In addition the valve 14 is held at a position spaced from the seat Ila.

A fluid, usually a gas at a high pressure, is then applied to the lower channel 11 from where it can pass to the pressure gauge. The pressure may, for example, be in the range from zero to 20000 psi absolute.

Removal of the pressure gauge is effected by performing the above steps in reverse order beginning with disconnection of the fluid supply.

The operation of the testing device shown in Figure 2 is similar to the operation of the device shown in Figure 1 with the exception that the clamping of the fluid-receiving member is performed in a different manner. When the inlet of the pressure gauge is received in the channel 15a the handle 25 can be moved downwardly from the position shown in Figure 2 in order to move the guide member 20 along slot 19. This causes the entire screw-thread 3b to engage with the screwthread provided on the external surface of the fluid-receiving member of the pressure gauge, thereby clamping the pressure gauge to the testing device. It also provides an effective seal against fluid flow between the screw-thread 3b and the external surface of the fluid receiving member.

The testing device also includes a safety mechanism to guard against the possibility of the pressure gauge being released before the supply of pressure to the lower channel 11 is switched off. It will be appreciated that when high fluid pressures are used such a situation could have disastrous consequences.

If the pressure gauge is released prior to switching off the fluid supply then the pressure from the fluid supply would immediately move the piston 5 in an upward direction which also causes movement of the valve stem 12 and the valve element 14 in an upward direction. Hence the valve element 14 would immediately be biased against seat lia as shown in Figure 1 and 2; in this position there is no fluid communication between the lowermost channel 11 and the intermediate channel 10. Hence the fluid supply to the pressure gauge would be disconnected before any disadvantageous effects could occur.

The provision of this safety mechanism is also useful where a number of devices 1 are connected to a single fluid supply, because it is not necessary to provide a separate plug for plugging those devices which are not in use.

The provision of the O-rings 28 makes possible the efficient operation of the device under a vacuum.

The bolt 13 may be provided with an internal screw-thread which engages an external screwthread provided on the valve stem 12. This enables the distance of the piston 5 from the body 2 to be adjusted.

Claims (12)

1. A fluid flow device comprising a fluid passageway adapted to receive a fluid receiving member, at least one retaining formation adapted to retain the fluid receiving member in said passageway, the or reach retaining formation being movable into and out of engagement with the fluid receiving member, and clamping means for clamping the formation in engagement with the fluid receiving member.

2. A fluid flow device according to Claim 1 in which the formation serves to provide a seal against fluid flow between the fluid passageway and an outer surface of the fluid receiving member.

3. A fluid flow device according to Claim 1 or 2 in which the formation comprises a screw-thread.

4. A fluid flow device according to Claim 1, 2 or 3 which includes a generally annular member having the or each formation disposed on an inner surface thereof.

5. A fluid flow device according to Claim 4 in which the annular member comprises two portions movable relative to one other into and out of engagement with the fluid receiving member.

6. A fluid flow device according to Claim 5 in which the two portions are pivotally connected so that they can move pivotally relative to one another.

7. A fluid flow device according to Claim 5 in which the two portions are movable linearly relative to one another.

8. A fluid flow device according to Claim 7 in which one of the portions is provided with an elongate slot and the other portion is provided with a guide member which is received in and guided by the slot.

9. A fluid flow device according to any preceding claim including an inlet, and the valve element biased against a valve seat by fluid pressure at the inlet, to prevent fluid flow through the fluid passageway to the fluid receiving member.

10. A fluid flow device according to Claim 9 further including valve actuating means, said valve actuating means serving to move the valve element off the valve seat when the fluid receiving member is received in the fluid passageway.

11. A fluid flow device according to Claim 10 in which the valve actuating means comprises an actuating member disposed within the fluid passageway, biasing means for biasing the actuating member in a position such that the valve is held on the valve seat, and a valve stem connected between the actuating member and the valve element.

12. A fluid flow device substantially as herein described with reference to and as shown in the accompanying drawings.