GB2284647A - Butterfly valve - Google Patents

Abstract

In order to facilitate assembly and disassembly of a butterfly valve, a trunnion 5 is adjustably positioned by means of a screw 9. Retraction of the screw allows the trunnion to move away from the valve disc 3. An end connector 2 is screwed into a cast iron valve housing 1 and engages a seal arrangement 6 around the operating shaft 4 and the trunnion 5. <IMAGE>

Description

IMPROVED BUTTERFLY VALVE The present invention relates to butterfly valves and in particular provides a new improved butterfly valve in which mechanisation and ease of assembly is improved.

In essence the new valve has a valve body provided with a central conduit, within which a butterfly element is fixed via two semi-axles, the lower of which is located by the action of an adjustment screw.

In one aspect the invention provides a butterfly valve in the form of a valve body casting and a butterfly disc having pivot poles on which said butterfly disc is pivotally mounted within said housing, said valve body casting having a transverse central conduit within which the butterfly disc pivot poles are carried on internal extremities of upper and lower semi-axles, and the lower semi-axle being adjustably maintained by an adjustment screw.

In a more specific form the invention may comprise improved butterfly valve characterized by the fact that this valve which has a valve body made of cast iron and which is crossed by a transverse central conduit presents, at the confluence of this conduit and the proper lateral part of the valve body, a threaded area at which will be mounted a side cover; the valve body is crossed, in longitudinal direction, by an upper semi-axle and by a lower semi-axle the internal extreme parts of which emerge to the inner part of the central conduit and in such a manner that they fasten themselves in the poles of a butterfly disc; the upper semi-axle ramains fixed within the inner part of a guide sleeve equipped with an intermediate joint for tightness, in cooperation with a head washer, whilst the lower semi-axle is fixed by means of incorporation an adjustment screw which is introduced in the lower part of the valve body.

It will be understood that in referring to upper and lower semi-axles, this refers to their position in one particular orientation of the device as can conveniently be shown in the drawings, and that either during assembly or during use the orientation of the device may change to one where their positions are different, however they will still be referred to as upper and lower semi-axles for convenience.

For a better understanding of the object of the present invention, an embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 indicates a view of longitudinal section and in elevation of the valve, and Figure 2 shows a variation of the side cover mounting.

The model of butterfly valve as per the enclosed drawing has the following component parts: 1. Valve body made of cast iron with lateral threading.

2. Threaded side cover for the valve body, made of cast iron.

3. Metallic butterfly disc.

4. Upper semi-axle made of metal.

5. Lower semi-axle made of metal.

6. Watertight ring made of elastomeric material.

7. Guide and watertightness sleeves.

8. Head washer.

9. Adjustment screw for lower semi-axle.

10. Screw for fixing of cover in the version according to Figure 2.

The new design of the valve is particularly suited to mechanization as well as to easy assembly, which is carried out in the manner described below.

On the valve body 1, conveniently mechanized, the lower semi-axle 5 is placed, and thereafter the elastomeric ring 6 is inserted in its housing.

This is followed by putting the butterfly disc 3 in its position, directing its rotating poles to the lower semi-axle 5 and to the upper semi-axle 4, between the ends of which the butterfly disc remains fixed.

The assembly of the valve continues with the mounting of the guide and watertight sleeves 7 to the upper semi-axle, and as well as of the adjustment screw 9 to the lower semi-axle.

By adding to the upper semi-axle the head washer 8, approaching the lower semi-axle to its final position through the adjustment screw, and by locating the threaded side cover in its position by means of rotating and sliding it through its thread, the assembly of the present butterfly valve is completed.

This way, the valve is prepared for receiving the necessary control or actuation by hand or from the pneumatic or electric devices in order to become operative within the circuit of pipes where the valve is installed.

The operation of the butterfly valve is effected by rotating the same a quarter of a turn which limits both the totally closed position and the totally open position.

The end part of the valve body 1 for connection of the conduit or the pipe, and the threaded side cover 2 are furnished with a special mechanization in order to favour the joining of the pipe by means of the quick joints that surround the ends of the valve, making it an integral part of the corresponding circuit.

Taking away the threaded side cover 2 of the valve body, it is very easy to introduce or to extract from the valve body 1 the elastomere ring 6 as well as the butterfly disc 3 during the mounting or disassembly procedures of the valve, assuring thereby the impossibility of any damage, and the total integrity.

The elastomeric ring 6 has a cross section in the form of an isocceles trapezium which assures stability within the housing sector situated in the inner part of the valve body in order to respond in a proper manner and with assurance to the forces this ring has to withstand during the intervals of fluid circulation and during the actuations of the butterfly disc.

By virture of the arrangement and the manner of mounting this model of butterfly valve, the watertightness is maintained independently of the change in the directional flow of the fluid within the circuit in which the valve is installed.

Due to the fact that the side ends of the valve connection with the pipe circuit are made of metal, the tightness established between the surfaces of the elastomer ring and of the butterfly disc cannot be influenced by any condition whatsoever of the extreme parts or of the lateral connections of the valve, and in this manner, the butterfly disc and its peripheral surface for watertightness are protected in the inner part of the valve body without any possibility of interference with the surface of the lateral connections, the flanges, etc., of the pipe circuit.

Hereby are assured good characteristics of closing and of operation in the course of time, even if the valve had been installed and removed in various and different circuits.

According to a first variation accepted by the new design of the butterfly valve, the threaded side cover 2 of the basic version here described may be replaced by a side cover mechanized without threading which is fixed and adjusted to the valve body 1 by means of several lateral screws 10 as indicated in Figure 2.

Furthermore, according to a second variation accepted by the new design, this threaded side cover 2 as per the basic version here described may be replaced by a laterial cover mechanized without threading and placed against and adjusted to each of the sides of the mentioned central body which is modified in this sense.

The two lateral covers will present externally the configuration of a flange, with tabs in the number of that of the screws or threaded tie rods which are necessary to maintain the mentioned covers jointed together.

The screws or outer threaded rie rods will remain in their positions as surrounding elements of the modified central valve body with the result that the latter is clamped between them.

At the same time, each of the lateral covers according to the first variation and to the second variation of design assures at its extreme part of contact with the valve body the operation and the tightness between the butterfly disc, the elastomere ring, and the lateral cover itself.

At its other end, the cover will have one of the normal configurations which are necessary for the actuation of the cover as element of attachment and tightness between the valve and the circuit of pipes in which the latter is installed.

With these variations also remain untouched the specific advantages of the basis version here described with regard to the simplicity and the proper characteristics of its mounting, to the stability during the circulation of flow, to the operations of opening and closing as well as with regard to the assurance of tightness between the valve and the circuit in which it is mounted.

Claims (7)

1. A butterfly valve in the form of a valve body casting and a butterfly disc having pivot poles on which said butterfly disc is pivotally mounted within said housing, said valve body casting having a transverse central conduit within which the butterfly disc pivot poles are carried on internal extremities of upper and lower semi-axles, and the lower semi-axle being adjustably maintained by an adjustment screw.

2. A butterfly valve according to claim 1 in which the internal extremities of the semi-axles are packed by provision of elastic tightness rings on which is placed also a side cover.

3. A butterfly valve according to claim 2 in which the elastic rings are of truncated conical shape with the smaller base directed inwards.

4. A butterfly valve according to any of claims 1 to 3 having a side cover which is screw threadably connected to a screw threaded region of the valve body casting.

5. A butterfly valve according to any of claims 1 to 3 having a side cover mounted to the valve body by means of screws.

6. Improved butterfly valve according to any preceding claim in which the valve has two covers, one on each side, to constitute the form of a flange and with tabs which can be fixed by means of screws.

7. A butterfly valve substantially as herein described with reference to the accompanying diagrammatic drawings.