GB2105008A - Valves - Google Patents

Abstract

A float controlled valve comprises a chamber with aligned openings, a detachable cap 12 carrying a sealing washer 9 on one opening and a tube 18 arranged to move under the action of the float in the second opening with a seal ring 17 sealing it. The sealing ring is located in position by means of a detachable holding element 16 accessible when the cap is off. Thus the sealing washer 9 and the sealing ring 17 may be replaced after the removal of the cap. <IMAGE>

Description

SPECIFICATION Valves BACKGROUND OF THE INVENTION This invention relates to valves.

A variety of valve types are known. Most conventional types rely on a movable valve member that seals off an orifice or valve seat in the closed position while it moves off the seat during opening to allow flow through the orifice. During closure the member is acted on by the pressure of the fluid so that the member has to press on its seat with a force which outbalances the pressure acting on the member and this force is constantly applied to the seat during closure.

Especiaiiy with float controlled valves this is a disadvantage. The larger the orifice and hence the force to be outbalanced, the larger the float and its lever arm have to be.

In many cases it would be an advantage to have a closure member held on a seat by means of a force which is independent of the pressure of the fluid to be controlled.

SUMMARY OF THE INVENTION A valve according to the invention comprises: a chamber, first and second axially aligned openings to the chamber, a third opening to the chamber constituting an inlet, a detachable cap closing the first opening, a sealing washer detachably carried by the cap, a tube arranged to move axially in the second opening between a first position in which its inner mouth abuts the sealing washer and positions in which fluid in the chamber may flow out of the chamber along the tube, a sealing ring around the tube preventing leakage of fluid from the chamber along the outside of the tube, and a detachable locating element holding the sealing ring in position, which element can be replaced through the first opening to allow for replacement of the sealing ring.

The sealing ring is preferably torroidal.

Thus with the valve of the invention it matters little whether the seaiing washer or the sealing ring wears out: firs,. Both can be replaced by removing the same detachable cap, which is preferably secured over the first opening by a screw threaded engagement.

Axial movement of the tube may be caused by a variety of devices such as a lever arm of a float, a diaphragm of the kind used in pressure control valves, by a double acting piston and cylinder arrangement and the like.

DESCRIPTION OF THE DRAWINGS Figure 1 is a section through a float controlled valve according to the invention, Figure 2 is a section through a modified version of a float controlled valve, Figure 3 is a section through a pressure control valve according to the invention, and Figure 4 is a section through a pilot operated valve according to the invention.

DESCRIPTION OF EMBODIMENTS In Fig. 1 there is a cylindrical valve body 10 provided with an inlet 11. The top of the body 10 is closed by means of a screw cap 1 2. The cap 1 2 holds in position an insert 1 3 which seals off the bottom of the chamber 1 4 inside the body 10 and provides a centrally holed boss 15, and a locating member 1 6 holding in position an O-ring 1 7.

A tube 1 8 constitutes the valve member and slides inside the ooss 1 5 and is sealed cn its outside by means of the During 1 7. Be tween the cap i 2 and the member l s hers is a washer 9 %yains-i which the inner mouth of the tube 1 8 seals on closure.

It will be seen that in the illustrated position there can be no flow from the chamber 1 4 to the interior of the tube 18. If the tube 18 is moved down, flow from the chamber 1 4 takes place through the tube 1 8.

In this embodiment the tube is moved by means of the lever arm 1 9 of a float (not shown). Upward movement of the tube 1 8 is assisted by means of a spring 20, but this spring is not essential to the working of the device. The spring 20 is held in place by means of a cap 21 on which the lever arm 19 is also pivoted as shown. A grub screw 6 holds the cap 21 in any angular position to which it has been adjusted to give the float a free moving action.

Opening of the valve of Fig. 1 is resisted only by the spring 20 (which need not be there) while closure is resisted only by the forces of gravity. A relatively small float and a short lever arm 1 9 can effect closure of almost any size valve. In the closed position, the force holding the mouth of the tube 1 8 against the washer 9 is not dependent on the pressure inside the chamber 14.

In the illustrated embodiment it is a simple matter to replace the washer 9 or the O-ring 1 7. This is done simply by unscrewing the cap 1 2 and in the case of the O-ring 1 7 removing the element 1 6. There is no reason to interfere with the pivots of the lever arm 1 9 as is the case with conventional float valves when worn washers have to be replaced.

Fig. 2 illustrates a simplified version of the valve shown in Fig. 1.

In this case the washer 9 not only acts as a seat but also seals the cap 1 2 to the body 1 0.

Also there is no insert to provide a centrally holed boss, but the tube 1 8 passes through the floor of the body 10 which also provides the pivot point for the lever arm 19. A screen 22 is provided in the inlet 11.

In this case the O-ring 1 7 is held in position by means of a locating element which is a press fit in a holed boss 8 upstanding from the floor of the body 10. The washer 9 is replaced merely by removing the cap 12, while with the cap 1 2 off the element 1 6 may be lifted out and the O-ring 1 7 replaced, if this is necessary.

An additional insert 7 is provided to support the washer 9 against possible sagging.

In the embodiment of Fig. 3 parts which are the same have the same reference numerals as in Fig. 1. At the top the only addition is that a filter screen 22 surrounds the chamber 14 as is usual with pressure control valves.

In this case the tube 1 8 is conrolled by means of a diaphragm 23 to which the lower end of the tube 1 8 is secured. The diaphragm 23 is positioned at one end of an outlet chamber 24 and ik biased towards that chamber by means of a spring 23. If the pressure in the chamber 24 is more than the spring pressure, the diaphragm 23 moves to push the tube 18 on to the washer 9. If the pressure in the chamber 24 drops. the spring causes the tube 1 8 to move off the washer 9 and flow can take place from the inlet 11 to the outlet chamber 24.

The open lower end of the tube 1 6 is controlled by a spring biased mushroom valve 25 to prevent flow of fluid in the cpposite direction along the tube 1 8.

In the embodiment of Figure 4 the body 10 is formed in its interior with a boss 30 to take the seal 1 7 around the tube 1 8 and has a floor 31. Depending from the floor 31 is a cylindrical skirt 32. A piston 33 on the tube 18 moves in the skirt 32 and is downwardly biased by means of a spring 34. A bleed hole 35 connects the chamber 1 4 with the space 35 around the skirt 32. A port 36 connects with the space 35.

The spring 34 is so chosen that at the inlet pressure of the fluid being controlled the tube 18 is pressed against the washer 9. If the pressure in the space 35 drops, the spring forces the tube 1 6 down and fluid flows along the tube 16.

As shown diagrammatically the port 36 is connected to a float controlled valve 37, which may be a valve such as that iliustrated in Fig. 1 or Fig. 2. The valve 37 is positioned in any suitable quiescent body of the liquid being handled and thus operates the larger valve which has been illustrated.

The valve 37 may be replaced by a suitable push-button valve so that the valve illustrated in Fig. 3 may become a flushing valve.

In all embodiments the washer 9 and the 0ring 1 7 may be replaced with ease by unscrewing the cap 1 2.

Claims (7)

1. A valve comprising: a chamber, first and second axially aligned openings to the chamber, a third opening to the chamber constituting an inlet, a detachable cap closing the first opening, a sealing washer detachably carried by the cap, a tube arranged to move axially in the second opening between a first position in which its inner mouth abuts the sealing washer and positions in which fluid in the chamber may flow out of the chamber along the tube, a sealing ring around the tube preventing leakage of fluid from the chamber along the outside of the tube, and a detachable locating element holding the sealing ring in position, which element can be replaced through the first opening to allow for replacement of the sealing ring.

2. The valve claimed in claim 1 in which the sealing ring is torroidal.

3. The valve claimed in either of the above claims in which the tube is caused to move by a lever arm carrying a float and pivoted to the chamber.

4. The valve claimed in either of claims 1 or 2 in which the tube is carried by a diaphragm.

5. The valve claimed in either of claims 1 or 2 in which the tube is caused to move under fluid pressure.

6. The valve claimed in any one of the above claims in which the cap is a screw cap.

7. A valve substantially as herein described with reference to Figs. 1, 2, 3 or 4 of the accompanying drawings.