ZA200904986B

ZA200904986B - A valve

Info

Publication number: ZA200904986B
Application number: ZA200904986A
Authority: ZA
Inventors: David Pieter Keth
Original assignee: David Pieter Keth
Priority date: 2008-04-18
Filing date: 2008-04-18
Publication date: 2010-08-25

Description

FIELD OF THE INVENTION

This invention relates to a valve, more particularly to a ball valve for use in water reticulation systems.

BACKGROUND TO THE INVENTION

In water reticulation systems, especially municipal systems, it is frequently desired to be able to reduce the flow of water to a premises without shutting off the flow entirely. To this end, orifice plates have often been inserted into the pipeline. These, however, are costly and time consuming to install. Ball valves do exist in which a slot or aperture is formed in the ball valve member.

These valves have three stop positions, a first position in which full flow through the fully open valve is permitted, a second position in which no flow through the closed valve is permitted and a third position where a trickle or relief flow or small continuous flow through the aperture or slot is permitted.

Slots are preferred for this type of valve as they are less prone to clogging and are easier to form in the ball valve member. Although effective, such valves do suffer the disadvantage that they do not permit varying rates of trickle flow to be obtained. Also, the size of the slot and the feed pressure determine the rate of flow in the trickle position. For a given pressure and desired trickle flow rate, the slot has to be configured accordingly at the time of manufacture. This can be inconvenient, especially where different pressures exist within the same system or area.

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SUMMARY OF THE INVENTION

In accordance with this invention there is provided a ball valve having a housing with an axial passage therethrough and ball valve member mounted in the passage between seals supported in the housing, a diametrical bore through the member, characterised in the ball valve member being rotatable in the housing through a lock having at least two stop positions defining trickle flow positions which permit varying degrees of trickle flow through the valve.

Further features of the invention provide for a further stop position to be provided defining a full flow position which permits full flow through the valve; for at least three trickle flow positions to be defined; for at least one, preferably at least two, trickle flow positions to be defined by aligning the ball valve member relative to the housing such that a small opening is provided therebetween; and for a further trickle flow position to be defined by exposing to flow only a restricted opening in diametrically opposite sides in the wall of the bore on one side of each end of the bore.

According to one aspect of the invention there is provided for a slot to be . provided in diametrically opposite sides of each end of the bore, the slots at each end having different dimensions and the diametrically opposite slots at opposite ends being substantially similar.

The invention also provides a lock for a ball valve substantially as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a perspective view of a ball valve;

P1866ZA00/COMPLETE (4 VALVE)

Figure 2 is sectional plan view of the ball valve in Figure 1;

Figure 3 is a perspective view of the ball valve member in Figure 1; and

Figure 4 is a perspective view of a second embodiment of a ball valve member.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

A ball valve (1) is shown in Figure 1 and 2 and includes a housing (2) with an axial passage (4) therethrough and a ball valve member (6) mounted in the passage (4) between seals (8) supported in the housing (2). The ball valve member (6) has a bore (10) extending diametrically therethrough and is rotatable in the housing (2) by means of a valve stem (not shown) which extends through a passage (not shown) normal to the flow passage (4) and is accessible externally of the housing (2).

A lock (12) is provided integral with the housing (2) over the valve stem (not shown) and through which the ball valve member (6) can be rotated within the housing (2). A key (not shown) is required to operate the lock (12) to so prevent unauthorised operation thereof. The ball valve (1) thus far described is known in the art.

According to the invention, diametrically opposed slots (15, 17) are provided in the wall of the bore (10) of the ball valve member (6) on one side of each end of the bore (10). The slots at the same end having different dimensions and the diametrically opposite slots the opposite ends being substantially similar.

P1866ZA00/COMPLETE (4 VALVE) )

S

The ball valve member (6) has three stop positions defined which a user may select. In the first stop position the bore (10) is co-axial with the passage (4) allowing full flow through the ball valve (1). The second and third stop positions are all trickle flow positions and each corresponds to a slot (15, 17).

In the second stop position, the ball valve member (6) is rotated so that the bore (10) is inclined to the flow passage (4) with only the slot (15), exposed to flow as shown in Figure 2. In the third stop position, only the slot (17) is exposed. Being smaller than the slot (15) it allows a reduced flow over the second stop position.

The stop positions will be marked on the stem or housing and preferably also by positive location of the stem with respect to the housing. Thus, the first stop position may be marked as “On” (20), the second stop position as “High” (22) and the third stop position as “Low” (23).

In this embodiment, no stop position is provided in which flow is prevented. It is illegal in certain instances to shut of water to residential premises and this assists in preventing the valve from being completely. shut off.

It will be appreciated, that selecting between the second and third stop positions permits varying rates of trickle flow to be achieved. This not only permits selectivity as to the amount of water permitted to various users, but also permits easier calibration of the valve when used with different water pressures. Thus, the same flow rate can be achieved with a relatively low pressure and the second stop position selected as can be achieved with a relatively high pressure and the third stop position selected.

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Many other embodiments of a ball valve member, and lock defining stop positions for operating the valve clearly exist which fall within the scope of the invention. For example, as shown in Figure 4, diametrically opposite slots (30) can be provided in the side of the bore (10) at opposite ends thereof.

The slots (30) are elongate and extend part way around the ball valve member (6). Varying the degree to which the slots (30) are exposed determines the rate of trickle flow therethrough. Also, their length is such that part of one is always exposed to flow in what would normally be the shut-off position of the ball valve member (6).

Further alternately, the trickle flow positions may be provided by not fully closing the valve member and leaving gaps between the valve member and housing, these being predetermined through calibration of the valve.

It will also be appreciated that a full flow stop position need not necessarily be defined on the lock. Although the ball valve member can be moved into a full flow condition, it is not necessary to provide a stop position on the lock corresponding to this condition.

Still further, more than two trickle flow positions can be provided, as can a no flow stop position, if desired. The valve member and housing can be made from any suitable materials, including plastics materials, and any suitable lock can be used to prevent unauthorised operation thereof.

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Claims

CLAIMS cL

1. A ball valve having a housing with a passage therethrough and ball valve member mounted in the passage between seals supported in the housing, with a diametrical bore through the valve member, characterised in the ball valve member being rotatable in the housing through a lock having at least two stop positions defining trickle flow positions which permit varying degrees of trickle flow through the valve.

2. A valve as claimed in claim 1 in which a further stop position is provided defining a full flow position wherein the bore is aligned with the passage and permits full flow through the valve.

3. A valve as claimed in claim 1 or claim 2 in which a slot is provided in \ diametrically opposite sides of each end of the bore, the slots at each end having different dimensions and the diametrically opposite slots at opposite ends being substantially similar.

4. A valve as claimed in claim 1 or claim 2 in which at least one trickle flow position is defined by aligning the ball valve member relative to the housing such that a small opening is provided therebetween.

5. A valve substantially as herein described and as illustrated with reference to Figures 1 to 3 or Figure 4. Dated this 17" day of July 2009 : VON SEIDELS ‘Intellectual Property Attorneys for the applicant P1866ZA00/COMPLETE (4 VALVE)