EAGLE™ 3A Welded Check Valve

What is a check valve in welding?

A welded check valve is a device used for backflow prevention that is permanently connected to the process piping using a butt welding process. Unlike a clamp valve that comes with gaskets and ferrules, a welded check valve has no removable parts because the valve body has been fused to the tubing through automatic orbital welding. The valve produces a smooth and uniform internal surface without any gaps or gaskets that may deteriorate and clamps that need to be re-tightened. In sanitary applications, welded connections have been used for permanent and safe applications since they do not create any possible contamination sites at the joint.

What are three types of check valves?

Sanitary check valve types can be classified into three distinct types. Let us look at these types in detail. These are spring-loaded ball check valves where a spring keeps the ball in place against a seat and the flow comes forward pushing the ball up to allow free passage. The second type is spring-loaded disc check valves where a spring holds the flat or profile disc in the right place against the seat. This is the type of configuration used in the valve seen in this page which is also the most commonly used type in hygienic processing. Thirdly, there are the swing check valves that open because of the action of the forward flow and close by gravity when the flow stops. It can be safely said that spring-loaded check types close faster than swing check types, and they can be installed in any orientation specifically while the swing check valves should be fixed in a proper position and are suitable for use in the large diameter pipes only.

Can you weld a valve?

A sanitary valve with butt-weld connections must be welded directly into the line of the particular process. The welding process must be carried out by an automatic welding machine operated by a qualified person and according to a certified welding technology. The weld must be penetrated totally, have a smooth and cremice-free, internal surface and be visually checked; in the case of the pharmaceutical application, it must also be boroscopically checked. The valve welded into a piping becomes an integral part of the system and cannot be removed without cutting the dear pipe. Therefore, welded valves are chosen for permanent installations, with no need for disassembly, and the absence of clamp loints allows one to reach the highest level of cleanliness and sterility.

What is the difference between welded and flanged valves?

A welded valve is a device that comes with butt-welding ends that allow for the immediate fusing of the valve and the adjacent pipe through orbital welding. A flanged valve, which is also referred to as a clamp valve, comes with Tri-Clamp ferrules that ensure the connection between the valve to the pipe via a clamp and gasket. The welded connection is permanent, creating a seamless joint that does not require the replacement of gaskets or retightening of clamps. The clamp connection, on the other hand, is renewable, therefore allowing for the removal of the valve for inspection, cleaning, and replacement. While welded valves are mostly preferred in sensitive settings where there is a need for cleanliness and sterility, the clamp styles are used in like juice and beer production processes where frequent disassembly is required. As a result, whether a welded connection or clamp connection will be used will depend on the needed level of sterilization, frequency of changing of lines, and the philosophy of maintainability and validation.