GB1588905A

GB1588905A - Air release and ventilating valves

Info

Publication number: GB1588905A
Application number: GB5426477A
Authority: GB
Original assignee: Neptune Glenfield Ltd
Current assignee: Neptune Glenfield Ltd
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-04-29

Description

(54) IMPROVEMENTS IN OR RELATING TO AIR RELEASE AND VENTILATING VALVES (71) We, NEPTUNE GLENFIELD LIMITED, formerly Glenfield & Kennedy (Valves) Limited, a British Company, of Kilmarnock, Ayrshire, Scotland do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to air release and ventilating valves.

Air release and ventilating valves for pipelines are already well known. One such valve is described in our prior specification no.

1,049,907. Another such valve is described in our prior specification 1,066,006.

Valves of this type are open at the top, the opening for passage of air into or out of the pipeline being masked by a cowl which is there merely to prevent the ingress of foreign matter. It is frequently desired for special operating conditions that the valve should be capable of providing free discharge conditions but restricted inward flow or of providing free inward flow conditions and restricted discharge. Since specific conditions vary from place to place the valve requires to be special for the particular location where it is to be used, yet it would be too inconvenient and expensive to construct each valve to provide the specific operating characteristics required.It is an object of the present invention to provide an auxiliary valve which can be fitted as an auxiliary valve to the top opening of a main air release and ventilating valve and which can be easily arranged to provide any specific conditions of discharge and/or inward flow.

A valve particularly for fitting as an auxiliary control valve to a main air release and ventilating valve according to the invention incorporates a base member formed with two faces, a main aperture extending through the member and debouching at opposite ends at the two faces and at least one passage one end of which terminates at a port located at a position on the outer surface of the member other than the annular faces and the other end of which terminates at a port on one face, a domed cover attached to the member to enclose at least a portion of the face containing the port and the adjacent end of the main aperture, a guide pin fixed to the bottom of the cover within the cover and projecting from the bottom of the cover towards the entrance to the cover and an obturator slidable on the pir. towards and from the adjacent face and arranged to shut off or establish respectively a connection between said main aperture and said passage.

The base member may conveniently be formed as a thick ring which may be formed from a thick disc, the poit located on the outer surface being on the periphery of the ring.

A disc of sealing material may be fitted to the face at which the passage terminates, the sealing material being cut away to provide access to the main aperture and to the port on the face.

In one construction the obturator is impermeable and is formed, e.g. its outer diameter is small enough, to leave clear the entry to the port on the adjacent face of the base member whatever the instantaneous position of the obturator on the pin. In this construction the valve is operative to provide flow only from the main aperture to the passage.

In another construction the obturator is formed, e.g. it is large enough in diameter to mask the port on the adjacent face of the base member when the obturator is against the face and the obturator is formed with at least one passage providing a permanent connection between the main aperture and the interior of the domed cover. In this construction the valve is operative to permit flow from the passage to the main aperture but to prevent flow in the opposite direction.

The base member may be formed with a by-pass vent connecting the passage and the main aperture, the effective cross sectional area of the by-pass vent being smaller than the cross sectional area of the passage. Means may be provided for varying the effective cross sectional area of the by-pass vent. Said means may be arranged to be capable of ,closing the bypass vent.

Preferably the base member is formed with several passages spaced around the main aperture.

The base member may be provided with means for attaching it to the body of a main air release and ventilating valve with which the valve is to be operative as an auxiliary valve.

The face of the base member remote from that engaged by the obturator may be formed with at least one annular groove for reception of a sealing ring such as an O-ring to form a seal between the valve and the main air release and ventilating valve to which it is to be attached as an auxiliary valve.

The disc of sealing material against which the obturator is engageable may be arranged to extend beyond the obturator and serve as a seal for the domed cover.

Practical embodiments of the invention are illustrated in the accompanying drawings in which Fig. 1 shows an air release and ventilating valve as described and claimed in the specification of our patent application No.

54263/77 Serial No. 1,588,904 and fitted with an auxiliary valve according to the invention arranged as a vented non-return valve i.e. a valve which permits maximum inflow to the main valve with a restricted outflow and Fig. 2 illustrates a valve as in Fig. 1 fitted with an auxiliary valve arranged to operate as a check valve which permits maximum outflow and automatic restriction of inflow.

Referring to the drawings 1 denotes a casing including a float chamber 2 formed with an opening 3 connectible to a pipeline and containing a float 4. 5 denotes an air chamber in communication with the float chamber by way of a passage 6. 7 denotes an air vent in the top of the air chamber 5.

8 denotes a valve element arranged to move vertically to close and open the vent 7. The float 4 is in operative connection with the valve element 8 by a push rod 9. 10 denotes generally an auxiliary valve fitted over the air vent 7.

Referring now to Fig. 1, 11 denotes a base member in the shape of a ring having a main aperture 12, the ring being formed with passages 13 each terminating at one end at a port 14 on the periphery of the ringlike base member and at the other end at a port 15 on the upper annular face of the base member 11. 16 denotes a domed cover enclosing the upper face of the base member 11 and presenting a guide pin 17 projecting towards the open end of the cover 16. 18 denotes an obturator slidable on the pin 17 towards and from the upper face of the disc 11. The disc is large enough to mask the ports 15 and is formed with apertures 19 providing a permanent connection between the main aperture 12 and the interior of the cover 16.The base member is formed with a by-pass vent which permits a limited escape of gas from the interior of the casing 1 and through the aperture 12 to one of the passages 13. The by-pass vent takes the form of a bar 20 screw threaded into the wall between the passage 12 and one of the passages 13 and formed with a blind hole 21 terminating in a transverse passage 22 located within the aperture 12. By screwing the bar 20 one way or the other the transverse passage 22 is masked to a less or greater extent by the wall of the aperture 12 and thus its effective area is varied from maximum to zero.

In operation of the valve of Fig. 1 when pressure in the casing 1 rises above atmospheric pressure this pressure is communicated through the apertures 19 in the obturator 18 to the interior of the cover 16. The pressure causes the obturator 18 to be pressed against the adjacent face of the base member 11 and seal the port 15 so that no gas can flow outwards through the passages 13. To make provision for a gradual drop of pressure within the valve casing 1 some of the gas can leak out through the by-pass vent by entering the passage 22 and flowing into the passage 21 and thus into the passage 13.If the pressure in the valve casing 1 drops below atmospheric pressure the pressure within the cover 16 becomes less than the ambient pressure and air entering through the passages 13 lifts the obturator 18 sufficiently to allow the air to flow into the aperture 12 and thus into the main valve casing 1.

Reference is now made to Fig. 2. In this construction the base member 11 and the cover 16 are similar to the base member 11 and the cover 16 illustrated in Fig. 1 except that the base member 11 is not fitted with a by-pass vent. The obturator 23 is, however, impermeable, i.e. is not formed with any apertures and is of a diameter such that the ports 1S are always open.

In this construction the weight of the obturator 23 or a vacuum condition occurring within the valve casing 1 causes the obturator to engage the upper surface of the base member and close the aperture 12 so that air cannot flow from the atmosphere by way of the passages 13 into the valve casing 1.

If, however, the pressure of gas in the valve casing 1 should rise above atmospheric, as soon as the thrust of the gas is sufficient to overcome the weight of the obturator 23 the obturator rises and the gas can escape to atmosphere by way of the passages 13.

Although in the construction of Fig. 2 it is not necessary to provide a by-pass vent 20 as illustrated in Fig. 1 it may be convenient to do so and keep it normally closed by screwing the bar to the position such that the passage 22 is closed. The auxiliary valve can then be changed from the type of Fig. 1 i.e.

the vented non-return valve to the type of Fig. 2 i.e. the check valve by simply substi tuting one type of obturator 18 or 23 for the other type of obturator 23 or 18, the by-pass vent being opened or closed as required.

It may be desired to make provision for a gradual drop in pressure within the main valve casing. Where this is required the bypass vent is incorporated and serves to leak away pressure in the valve casing at a controlled rate, the controlled rate being adjustable where the by-pass vent is fitted with means for varying its cross sectional area.

WHAT WE CLAIM IS:- 1. A valve incorporating a base member formed with two faces, with a main aperture extending through the member and debouching at opposite ends at the two faces and with at least one passage one end of which terminates at a port located at a position on the outer surface of the member other than the annular faces and the other end of which terminates at a port on one face, a domed cover attached to the member to enclose at least a portion of the face containing the port and the adjacent end of the main aperture, a guide pin fixed ro the bottom of the cover within the cover and projecting from the bottom of the cover towards the entrance to the cover and an obturator slidable on the pin towards and from the adjacent face and arranged to shut off or establish respectively a connection between said main aperture and said passage.

t. A valve as claimed in claim 1 in which the base member has the form of a thick ring, the port located on the outer surface of the base member being on the periphery of the ring.

3. A valve as claimed in claim 1 in which a disc of sealing material is fitted to the face at which the passage terminates, the sealing material being cut away to provide access to the main aperture and to the port on the face.

4. A valve as claimed in claim 1 in which the obturator is impermeable and is formed to leave clear the entry to the port on the adjacent face of the base member whatever the position of the obturator on the pin.

5. A valve as claimed in claim 1 in which the obturator is formed to mask the port on the adjacent face of the base member when the obturator is against the face and the obturator is formed with at least one passage providing a permanent connection between the main aperture and the interior of the domed cover.

6. A valve as claimed in claim 1 in which the base member is formed with a by-pass vent connecting the passage and the main aperture, the effective cross sectional area of the by-pass vent being smaller than the cross sectional area of the passage in the disc.

7. A valve as claimed in claim 6 in which means is provided for varying the effective cross sectional area of the by-pass vent.

8. A valve as claimed in claim 7 in which the means for varying the effective cross sectional area of the vent is arranged to be capable of closing the bypass vent.

9. A valve as claimed in claim 1 in which the base member is provided with means for attaching it to the body of a main air release and ventilating valve with which the valve is to be operative as an auxiliary control valve.

10. A valve as claimed in claim 1 in which the face of the base member remote from that engaged by the obturator is formed with at least one annular groove for reception of a sealing ring to form a seal between the valve and the main air release and ventilating valve to which it is attached as an auxiliary control valve.

11. A valve as claimed in claim 3 in which the disc of sealing material against which the obturator is engageable is arranged to extend beyond the obturator and serve as a seal for the domed cover.

12. A valve substantially as described with reference to Fig. 1 of the accompanying drawings.

13. A valve substantially as described with reference to Fig. 2 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. tuting one type of obturator 18 or 23 for the other type of obturator 23 or 18, the by-pass vent being opened or closed as required. It may be desired to make provision for a gradual drop in pressure within the main valve casing. Where this is required the bypass vent is incorporated and serves to leak away pressure in the valve casing at a controlled rate, the controlled rate being adjustable where the by-pass vent is fitted with means for varying its cross sectional area. WHAT WE CLAIM IS:-

1. A valve incorporating a base member formed with two faces, with a main aperture extending through the member and debouching at opposite ends at the two faces and with at least one passage one end of which terminates at a port located at a position on the outer surface of the member other than the annular faces and the other end of which terminates at a port on one face, a domed cover attached to the member to enclose at least a portion of the face containing the port and the adjacent end of the main aperture, a guide pin fixed ro the bottom of the cover within the cover and projecting from the bottom of the cover towards the entrance to the cover and an obturator slidable on the pin towards and from the adjacent face and arranged to shut off or establish respectively a connection between said main aperture and said passage.