CROSS-REFERENCE TO RELATED APPLICATION

This application is claims priority to and the benefit of Great Britain Application No. 1905393.3, filed Apr. 16, 2019 entitled VALVE FITTING, which is incorporated herein by reference in their entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates to an assembly, a method and a kit of parts for preventing the unintentional flow of flowable material out of a container through a valve.

BACKGROUND

Butterfly valves are a well-known type of valve for controlling the flow of material out of a container. They typically comprise a valve housing which is connectable to the container, a rod pivotally mounted within the valve housing and a circular disc mounted to the rod. An actuator is typically located outside of the valve housing and is connected to one end of the rod. By rotating the actuator the disc is caused to turn to a position perpendicular to the flow of material (closed position) or to a position parallel to the flow of material (open position).

A known problem of butterfly valves is that improper positioning of the actuator or intentional or unintentional adjustment of the actuator may result in material in the container being inadvertently dispensed. Accordingly, any material that is inadvertently dispensed may become contaminated. In the context of additive manufacturing where the material is typically a valuable metal powder, this is undesirable and will often result in valuable powder having to be discarded. A valve cap can be used to close the opening of the butterfly valve through which powder is dispensed, but once fitted, an operative is unable to check whether the valve is open or closed meaning that valuable powder may be lost upon removing the cap from the housing.

In view of the above, it is an object of embodiments of the disclosure to provide an assembly and method for preventing material in a container from being unintentionally dispensed.

SUMMARY

According to a first aspect of the disclosure there is provided an assembly for preventing the unintentional flow of flowable material out of a container through a valve, the valve comprising a housing; a flow control element rotatable between an open configuration and a closed configuration, and an actuator for moving the flow control element, wherein the assembly comprises a fitting adapted for insertion into the housing which in use locks the flow control element in its closed configuration by preventing rotation of the flow control element and means for detachably securing the fitting to the housing.

In addition to preventing rotation of the flow control element to prevent the inadvertent discharge of powder through the valve, the fitting may also be adapted to plug an opening in the housing, i.e. the fitting blocks the opening.

The fitting may be configured so that it cannot be fully inserted into the housing when the flow control element is in its open configuration.

In some embodiments the fitting is adapted to collect flowable material that may inadvertently escape from the container.

The fitting may comprise a cylindrical tube and a plate arranged to close one end of the cylindrical tube. Once inserted into the housing, the free end of the cylindrical tube obstructs and prevents rotation of the flow control element. Moreover, by closing one end of the cylindrical tube with the plate the fitting is able to collect small quantities of flowable material that may inadvertently escape from the container.

The end of the cylindrical tube opposite the plate may be free from formations, e.g. protrusions or recesses. The absence of formations in the cylindrical tube simplifies its construction and reduces the cost of manufacturing the fitting. It also reduces the risk that flowable material in the container is contaminated with flowable material that was previously held in the container.

The plate may be substantially circular in plan. In some embodiments the plate may comprise a downwardly tapering side wall. The tapering side wall helps to secure the fitting to the valve housing, e.g. by clamping and also enables the plate to be picked more easily, especially when the plate is placed on a flat surface prior to use.

The diameter of the plate may be greater than the diameter of the cylindrical tube, and in use forms a flange for connecting to a corresponding flange on the valve housing. The plate may comprise a circular groove for receiving a seal member. In particular, the seal member may be an O-ring. The seal member may be formed from a deformable material such as rubber or silicone.

The housing may be formed from a first housing part and a second housing part. The first housing part may be adapted for connection to the outlet pipe of the container while the second housing part may be adapted for connection to an inlet pipe of an additive manufacturing machine and to the fitting. In particular, the first housing part may be provided with a first connection flange and the outlet pipe may be provided with a first corresponding connection flange. Similarly, the second housing part may be provided with a second connection flange and the inlet pipe of the additive manufacturing machine may be provided with a second corresponding connection flange. Each connection flange and each corresponding connection flange may comprise a circular recess adapted to receive a seal member. A gasket may be provided between the first housing part and the second housing part.

When a seal member is provided in the circular groove and the fitting is brought into engagement with the valve housing, a seal is formed between the plate of the fitting and the housing. In embodiments where the housing comprises a first housing part and a second housing part, the cylindrical tube is inserted into the second housing part and the plate is brought into sealing engagement with the second connection flange of the second housing part.

The fitting may be formed from a metal or metal alloy. Fittings made of metal or metal alloys are robust and inexpensive to manufacture. Preferably the fitting is smooth and substantially free from crevices and pits. In particular, the interior surface of the cylindrical tube and the top surface of the plate are preferably free from crevices and pits since these are known to act as corrosion sites and also increase the risk of contamination. In some embodiments, the fitting is formed from stainless steel which offers superior corrosion resistance. In other embodiments the fitting may be formed from a plastics material.

The valve may be a butterfly valve in which case the flow control element may comprise a substantially circular disc mounted on a rod. The rod may be connected to or extend into the actuator so that when the actuator is rotated, the disc is caused to rotate between a first configuration that prevents flowable material from flowing out of the container and a second configuration which permits the flow of flowable material out of the container. Alternatively, the valve may be any valve with an eccentric rotatable part, e.g. a flap valve.

The actuator may comprise an elongate handle although other shaped handles, or in certain instances, wheels can be used.

According to a second aspect of the disclosure there is provided an assembly for preventing the unintentional discharge of flowable material from a container, wherein the assembly comprises a valve comprising a housing, a flow control element rotatable between an open configuration and a closed configuration and an actuator for moving the flow control element, and a fitting adapted for insertion into the housing which in use locks the flow control element in its closed configuration by preventing rotation of the flow control element.

In some embodiments the flow control element may comprise a substantially circular disc mounted on a rod. The actuator which is configured to move the flow control element may comprise an elongate handle. The assembly may comprise means for detachably securing the fitting to the housing, e.g. a clamp. Alternatively, the fitting may be detachably secured to the housing through an interference fit.

The assembly may comprise a container. The container may have a part conical main body which leads into an outlet pipe. The container is preferably formed from a metal alloy such as stainless steel. Stainless steel offers superior corrosion resistance and is relatively inert meaning it tends not to interact with flowable material that is being stored in the container. In one embodiment the container may be a hopper.

The container may comprise a flowable material such as powder. In particular, the flowable material may be metal or metal alloy powder for use in additive manufacturing.

According to a third aspect of the disclosure there is provided a method of preventing the unintentional discharge of flowable material from a container through a valve, the valve comprising a housing; a flow control element rotatable between an open configuration and a closed configuration and an actuator for moving the flow control element, wherein the method comprises the steps of inserting a fitting into the housing to lock the flow control element in its closed configuration and detachably securing the fitting to the housing.

The method according to the second aspect of the disclosure may, as appropriate, incorporate any or all features discussed above in relation to the assembly according to the first aspect of the disclosure.

In some embodiments the fitting may be detachably secured to the housing using a clamp.

According to a fourth aspect of the disclosure, there is provided a kit of parts comprising a valve for a container for storing flowable material, the valve comprising a housing; a flow control element rotatable between an open configuration and a closed configuration and an actuator for moving the flow control element; a fitting adapted for insertion into the housing and means for detachably securing the fitting to the housing.

The kit according to the third aspect of the disclosure may, as appropriate, incorporate any or all features discussed above in relation to the assembly according to the first aspect of the disclosure.

The means for detachably securing the fitting to the housing may comprise a clamp.

