Interlocking small diaphragm valves

Usually located in wash-down areas, these small valves commonly control the flow of high purity water in closed loop systems. Because of the valves’ small size, conventional stainless steel interlocks are usually too big and heavy.

In a bid to solve this problem, Smith Flow Control, a specialist in valve interlocking equipment, has developed a new interlock for use with diaphragm valves in these and other hygiene-critical applications.

The new interlock uses a rotational Ellis lock mechanism that is said to be suitable for this application due to its compact design. It has an Acetal plastic body, which is lightweight and well suited for use with small diaphragm valves. It is also resistant to moisture, solvents and many other neutral chemicals. Despite this, it is designed to be tough, hardwearing and has a high resistance to repeated impacts. The Ellis key has a spring-loaded rubber seal, preventing water ingress during washdown or sterilisation procedures.

"Smith Flow Control is renowned for its heavy duty mechanical interlocks for the oil and gas industries, but this new lock design demonstrates our ability to provide interlocks for specialist applications, such as small diaphragm locks,” commented Dan Kelly, the company’s North American general manager.