IES68075B2 - Valves - Google Patents

Abstract

A fluid flow control value useful for metering milk flowing into and out of a milk tanker consists of a closed fluid flow loop, four equally spaced ports, and four butterfly valves, arranged one each between each pair of ports.

Description

VALVES FlaHdl of the Invention The present invention relates to valves, and relates particularly though not exclusively to valves suitable for use in metering a flow of milk into and out of a milk tanker comprising a valve housing, four ports, and a valve mechanism which can be set to a first valve setting in which fluid can flow between a first and a second port and between a third and a fourth port and can be set to a second valve setting in which fluid can flow between a first and a fourth port and between a second and a third port.

When a milk tanker collects milk from farms it is necessary to meter the milk collected at each farm as a basis for making payments to the farmer. When the milk tanker subsequently delivers the milk to a dairy it is necessary to meter the milk to determine the amount received by the dairy. For this purpose the tanker is provided with a milk meter. In order to ensure accurate metering, an air eliminator for collecting any bubbles entrained in the flow of milk is also provided, and this is located immediately upstream of the meter so that all bubbles are removed from the milk immediately prior to flowing into the meter. In order to avoid duplication, that is to say one air 368075 . 2 eliminator and meter for liquid flowing into the tanker and another air eliminator and meter for liquid flowing out of the tanker, a liquid flow arrangement is provided including just one air eliminator and one milk meter and a valve of the type mentioned above for directing the liquid flow along two alternative flowpaths, one for inflow and one for outflow, but in each case flowing firstly through the air eliminator and secondly through the meter.

Prior Art.

In the currently used valve, the housing consists of a hollow cylinder. The four ports are mutually spaced apart about the circumferential surface of the hollow cylinder. The valve mechanism consists of a smaller cylinder which is a close fit in the cylindrical valve housing, and includes a pair of mutually parallel spaced apart bores or passages for linking neighbouring ports. In one orientation of the valve member, the first port is linked to the second by one of the bores, and the third port is linked to the fourth by the other bore. The valve member can be rotated through 90°, and the first port is then connected to the fourth port and the second port is connected to the third port.

The principal disadvantage of the currently used valve is that it is very expensive. It is rather large, and bearing in mind that it is made of stainless steel which is expensive, this leads to expensive material costs. Furthermore, the two cylinders must fit one another very exactly in order to prevent leakage, and therefore there are expensive production costs.

Object aind Salary of the Invention The object of the present invention is to provide a less expensive valve.

The invention provides a fluid flow control valve comprising: a valve housing; a first, second, third and fourth fluid port; and a valve mechanism which can be set to a first valve setting in which the fluid can flow between a first and a second port and between a third and a fourth port and can be set to a second valve setting in which fluid can flow between a first and a fourth port and between a second and a third port; characterised in that the valve housing consists of a fluid flow closed loop; the ports are mutually spaced apart along the length of the loop; and the valve mechanism consists of four valves in the loop, one between each pair of ports, each of which may be opened or closed.

It will be appreciated that the overall construction of the valve of the invention may be made considerably smaller than the prior art valve, therefore using less material. Furthermore, the four valves which constitute the valve mechanism may be of relatively simple type so that the production costs are less.

Preferably the four valves are butterfly valves.

Preferably, the four butterfly valves are mutually linked so as to allow simultaneous operation of the valves, closing two opposite valves while opening the other two opposite valves and vice versa.

Other features and advantages of the invention will become apparent from the description which follows.

Brief Description of tlhis Drawings The invention will now be described more particularly with reference to the accompanying drawings which show, by way of example only, two constructions of valve according to the invention. In the drawings: Figure 1 is a plan view of the first construction; and Figure 2 is a similar view of the second construction.

Detailed Description of the Preferred Embodiments Referring to Figure 1, a valve consists of a valve housing generally designated 1 in the form of a closed loop, four equally spaced ports 2a, 2b, 2c and 2d, and four butterfly valves indicated by 3a, 3b, 3c and 3d, each of which is operable by means of the corresponding handle 4a, 4b, 4c and 4d.

As shown in Figure 1, butterfly valves 3a and 3c are in the open (liquid flow) setting and butterfly valves 3b and 3d are in the closed (no liquid flow) setting. Accordingly, port 2a is connected to port 2b and port 2c is connected to port 2d.

The handles 4a, 4b, 4c and 4d may each be operated to set the butterfly valves to the alternative setting, that is to say each butterfly valve would be in the setting opposite to that shown in Figure 1. As a result port 2a is connected to port 2d, and port 2b is connected to port 2c.

Having now described the valve arrangement, its use will now be described. Port 2b is connected to a tank (not shown) containing liquid milk, for example the tank at a farm. Port 2d is connected to the milk tanker. Port 2c is connected to the upstream side of an air eliminator and milk meter pair (not shown) and port 2a is connected to the downstream side of the air bubble and milk meter pair. When it is desired to deliver milk, that is to permit liquid flow from the tanker via the air eliminator and meter pair to the tank, the handles 4a, 4b, 4c and 4d are set in the setting shown in Figure 1. When it is desired to collect milk from the tank, that is to permit liquid flow from the tank via the air eliminator and meter pair, the handles 4a, 4b, 4c and 4d are set to the alternative setting.

Although not shown in the drawings, it is possible to provide a simple mechanical linkage between the handles of the four butterfly valves. Such a linkage would have two advantages. Firstly, the necessary resetting of the butterfly valve settings could be accomplished in one action instead of four. Secondly, there is less possibility of error.

From a consideration of Figure 1, it will be appreciated that the valve housing 1 can be made from four identical components which can be assembled together by welding. One of the four components is identified by means of a dashed line, and it will be seen that it consists of a straight length of piping, a butterfly/ valve part way along the length, and an angled port at one end.

Turning now to Figure 2, this shows a minor variant, the valve housing 10 is again assembled from four components. In this case, each component is simpler, in particular the component, again indicated by a dashed line, includes an in-line port at one end. However, the individual components are also somewhat larger.

Claims (4)

1. A fluid flow control valve comprising: a valve housing; a first, second, third and fourth fluid port; and a valve mechanism which can be set to a first valve setting in which the fluid can flow between a first and a second port and between a third and a fourth port and can be set to a second valve setting in which fluid can flow between a first and a fourth port and between a second and a third port; characterised in that the valve housing consists of a fluid flow closed loop; the ports are mutually spaced apart along the length of the loop; and the valve mechanism consists of four valves in the loop, one between each pair of ports, each of which may be opened or closed.

2. A fluid flow control valve according to claim 1 in which the four valves are butterfly valves.

3. A fluid flow control valve according to claim 1 or claim 2 in which the four valves are mutually linked so as to allow simultaneous operation of the valves, closing two opposite valves while opening the other two opposite valves and vice versa.

4. A fluid flow control valve substantially as herein described with reference to and as shown in Figure 1 or Figure 2 of the accompanying drawings.