GB2447327A

GB2447327A - Non-return valve unit

Info

Publication number: GB2447327A
Application number: GB0803286A
Authority: GB
Inventors: Luigi Aita; Franco Daudo
Original assignee: Elbi International SpA
Current assignee: Elbi International SpA
Priority date: 2007-03-08
Filing date: 2008-02-22
Publication date: 2008-09-10
Also published as: GB0803286D0; ITTO20070035U1

Abstract

A non-return valve unit comprises a body 11 having at least one inlet opening 17 and at least one outlet opening 13d for hydraulic fluid, a valve seat 14, and a closure member 20 which can move from a closure position on the seat 14 to an open position against the action of a biasing spring 22 under a pressure of liquid supplied to the inlet opening 17. Upstream of the inlet opening 17 the body 11 has an integral perforated element 18 suitable for acting as a filter for the inlet flow.

Description

NON-RETURN HYDRAULIC VALVE UNIT

DESCRIPTION

The present invention relates to a non-return hydraulic valve unit, particularly for use in heating boilers and the like.

More specifically, the subject of the invention is a non-return valve unit of the type comprising: a body which has at least one inlet opening and at least one outlet opening for a flow of a hydraulic fluid, and in which a valve seat is defined between the inlet and outlet openings, and a closure member mounted so as to be movable in the body, in which it can move from a closure position on the seat to an open position relative to the seat under the effect of the pressure of a flow of fluid supplied to the inlet opening, against the action of associated resilient biasing means urging it against the seat.

Non-return valve devices of this type are used in so-called cartridge units which can be manually fitted in and removed from corresponding seats in user apparatus such as boilers and the like.

Quite frequently, the flow of fluid which is intended to flow through the non-return valve unit in such applications has to be filtered. Currently, filters that are used for this purpose are formed as autonomous devices to be placed in corresponding seats provided in the user hydraulic circuits.

This involves additional fitting operations with a consequent increase in costs.

The object of the present invention is to propose a solution which overcomes the above-mentioned disadvantages of

solutions of the prior art.

This and other objects are achieved, according to the invention, by a non-return valve unit of the type specified above, characterized in that, upstream of the at least one inlet opening, the body of the valve unit has an integral perforated element suitable for acting as a filter for the inlet flow of hydraulic fluid.

In one embodiment, the integral element of the body of the valve unit is shaped substantially as a cylindrical cup which projects axially from the body and has a perforated cylindrical side wall as well as a substantially circular, flat distal wall which is also perforated.

The body of the valve unit may advantageously comprise a first portion and a second portion which can be snap-coupled, the first portion forming the inlet opening, the perforated filter element and the valve seat and the second portion defining guide means associated with the closure member and stop means against which the resilient means associated with the closure member react.

With a view to its being fitted in a receptacle of a cartridge unit or the like, the valve unit according to the invention is advantageously provided with an outer sealing ring, carried by the first portion of the body, for leaktight engagement with the side wall of the user receptacle.

Further characteristics and advantages of the invention will become clear from the following detailed description which is given purely by way of non-limiting example, with reference to the appended drawings, in which: Figure 1 is a perspective view of a cartridge unit for a boiler or the like including a non-return valve unit according to the present invention, Figure 2 is a perspective view of a non-return valve unit according to the present invention, and Figure 3 is view of the valve unit sectioned on the line 111- 111 of Figure 2 and on an enlarged scale.

A cartridge unit for a hydraulic user apparatus such as a boiler for a heating system or the like is generally indicated C in Figure 1.

In the embodiment shown by way of example, the cartridge C comprises a body with a substantially circular end element or head 2, an intermediate element 3 of reduced cross-section, and a substantially cylindrical end portion 4.

The end portion or head 2 may have a substantially diametral external projection 2a that can be used for facilitating gripping of the cartridge unit C during operations to fit it in/remove it from the seat in which it is to be used.

The end portion or head 2 has a sealing ring 5, for example, made of elastomeric material, for liquid-tight engagement with a corresponding wall portion of the seat (not shown) in which the cartridge unit C is used.

The cylindrical end portion 4 also has an external toric sealing ring 6 for liquid-tight engagement with a corresponding wall portion of the seat.

The end portion 4 of the cartridge unit C is substantially hollow and a non-return valve unit, generally indicated 10, is fitted inside it in a liquid-tight manner.

With reference to Figures 2 and 3, the non-return valve unit comprises a body 11 which, in the embodiment shown by way of example, is formed by two portions 12 and 13 which are snap-coupled, as can be seen in Figure 3 in particular.

On the side facing the portion 13, the portion 12 of the body 11 defines an internal valve seat 14 which is substantially frustoconical in the embodiment shown.

The portion 12 of the body 11 has an external annular groove housing a toric sealing ring 16 to be applied in a liquid-tight manner against the inner surface of the side wall of the end portion 4 of the cartridge unit C of Figure 1.

With reference to Figure 3, an inlet opening 17 for receiving a flow of liquid is formed upstream of the valve seat 14 in the portion 13 of the body 11. A filter element, generally indicated 18, is formed integrally with the portion 12 of the body 11 around the opening 17.

In the embodiment shown, the integral filter element 18 is shaped substantially like a cylindrical cup which projects axially from the portion 12 of the body 11 and has a perforated cylindrical side wall iBa and a substantially circular, flat distal wall 18b which is also perforated.

In the embodiment shown, the second portion 13 of the body 11 comprises an annular end portion 13a which is snap-engaged on the portion 12 of the body. A plurality of substantially La-shaped longitudinal connection appendages 13b extend from the annular end portion 13a (see also Figure 2). The distal ends of the connection appendages 13b are connected to an integral element l3c having a central opening 19 (Figure 3).

A closure member mounted so as to be movable in the body 11 between the portions 12 and 13 thereof is generally indicated in Figure 3.

In the embodiment shown, the closure member 20 has a head 20a carrying an external toric sealing ring 21, and a shank 20b which extends through the opening 19 in the portion 13c of the body 11.

A helical spring, indicated 22, is interposed between the head 20a of the closure member 20 and the element 13c of the portion 13 of the body 11. The helical spring 22 urges the closure member 20 into engagement, by means of its sealing ring 2]., with the valve seat 14.

A plurality of outlet openings 13d are defined between the appendages 13b of the portion 13 of the body 11; the flow of liquid passing through the valve unit 10 flows through the outlet openings 13d in use.

The connection appendages 13b help to guide the movement of the head 20a of the closure member 30 in operation.

The above-described non-return valve unit 10 is normally closed; in the absence of sufficient liquid pressure on the upper surface of the head 20a of the closure member 20, the helical spring 22 keeps the closure member in the position shown in Figure 3 in which the sealing ring 21 bears against the valve seat 14.

When sufficient liquid pressure acts on the top of the head 20a of the closure member 20 in operation, the closure member moves away from the valve seat 14 in the body 11, thus allowing the flow of liquid flowing through the inlet opening 17 to emerge through the outlet openings 13d defined between the appendages 13b.

In operation, the perforated tubular element 18 integral with the portion 12 of the body 11 performs a preliminary filtering action on the liquid which is to pass through the valve unit 10.

With the valve unit according to the invention, it is no longer necessary to provide a separate device for filtering the flow of liquid that is to pass through the non-return valve and then fit it in a suitable seat; this brings advantages in terms of a simplification of the construction and of the fitting and removal operations, and a consequent reduction in costs.

Naturally, the invention extends to all variants which achieve equal utility by virtue of the same innovative concepts.

Claims

1. A non-return valve unit (10), particularly for boilers and the like, comprising: a body (11) which has at least one inlet opening (17) and at least one outlet opening (13d) for a flow of a hydraulic fluid, and in which a valve seat (14) is defined between the inlet and outlet openings (17, 13d), and a closure member (20, 21) mounted so as to be movable in the body (11) in which it can move from a closure position on the seat (14) to an open position relative to the seat (14) under the effect of the pressure of a flow of liquid supplied to the inlet opening (17), against the action of associated resilient biasing means (22) urging it against the seat (14), the valve unit (10) being characterized in that, upstream of the at least one inlet opening (17), the body (11) has an integral perforated element (18) suitable for acting as a filter for the inlet flow of fluid (2)

2. A valve unit according to Claim 1 in which the integral element (18) of the body (11) is shaped substantially as a cylindrical cup which projects axially from the body (11) and has a perforated cylindrical side wall (18a) and a substantially circular, flat distal wall (18b) which is also perforated.

3. A valve unit according to Claim 1 or Claim 2 in which the body (11) comprises a first portion and a second portion (12, 13) which are snap-coupled, the first portion (12) forming the inlet opening (17), the filter element (18) and the valve seat (14), the second portion (13) defining guide means (13b, 19) associated with the closure member (20) and stop means (13c) against which the resilient means (22) associated with the closure member (20) react.

4. A valve unit according to Claim 3 in which the body (11) has an outer sealing ring (16) carried by the first portion (12) of the body (11) for leaktight engagement with a side wall of a receptacle (4) in which the valve unit (10) is available for use.

5. A cartridge unit for a boiler and including a non-return valve unit according to any of claims 1 to 4.

6. A non-return valve unit according to claim 1, substantially as herein described with reference to and as illustrated in Figures 2 or 3 of the accompanying drawings, or a cartridge unit for a boiler and including a non-return valve unit according to claim 1, substantially as herein described with reference to and as illustrated in Figure 1 of the accompanying drawings.