Ask the experts: How does a solenoid valve work?

BM Engineering Supplies in Glasgow are a long-standing distributor of Burkert’s market-leading fluid control products; including solenoid valves. We spoke to Scott Miller from BM Engineering Supplies LTD about the uses and importance of Solenoid Valves.

What are solenoid valves?

Scott from BM Engineering Supplies explains that a solenoid valve is an electro-mechanical valve used to control the flow of liquid or gas. This works by the solenoid converting an electrical signal into a mechanical movement. This then sends a signal to the coil, triggering movement within the valve. As a result of this, solenoid valves are usually described as pilot operated or directly operated.

What is a pilot operated solenoid valve?

Scott goes on to explain that a two-way pilot operated solenoid valve has two chambers, separated by a diaphragm. Scott tells us, “the upper chamber is connected to the upstream through a pilot hole in either the cover or diaphragm. When this coil is charged, the core lifts off the orifice seat, which allows the operating chamber to depressurise. The thrust of the upstream pressure under the diaphragm continues, lifting this diaphragm and opening the valve.”

“Pilot operated solenoid valves only operate with upstream pressure, and do not operate at zero pressure. A minimum pressure differential across the valve is required to keep them open or closed. These pilot operated solenoid valves can provide high-flow rates at high pressures with lower power consumption”.

What are direct-acting solenoid valves?

“Direct-acting solenoid valves do not use a diaphragm, instead their seal is part of the moving core. Two-way direct acting solenoid valves have a spring that holds the core against the seal. When this coil is charged, this spring is overcome and the seal is lifted from the orifice seat opening the valve and allowing the material to pass through the valve.”

Scott goes on to tell us; “these direct acting solenoid valves are used when there is no line pressure applied”. He then explains, “Typical applications would include a cleaning line when a pump supplies bursts of water through the line.” This is in contrast to a pilot operated valve, which requires some pressure for the valve to stay closed.

BM Engineering Supplies recommends Bürkert solenoid valves

Bürkert have been operating throughout the United Kingdom and Ireland for over 40 years; working hard to develop and build experienced partners and superior products. BM Engineering Supplies and Bürkert have worked in conjunction for years, so you never have to look far to source industry-leading products from Bürkert.

With over 40 years of experience and expertise, Bürkert can supply superior fluid control whether your application is filling, level, flow, pressure or temperature. BM Engineering Supplies stock the full range of Bürkert solenoid valves, process and analytical valves, pneumatic valves, sensors and controllers.

Browse the BM Engineering Supplies solenoid valve range by heading over to their website.