Elektrogas VMRNA Automatic Vent Valve

The Elektrogas VMRNA is a normally-open vent valve for industrial combustion systems. Because the valve is open when de-energized, VMRNA can be thought of as the opposite of a safety shut-off valve (closed when de-energized).

How they work

A reverse-acting solenoid valve, VMRNA is normally open. That means you must apply power to close the valve. An internal spring pushes against a magnetic core, keeping the sealing disc raised and the valve open. Applying power to the coil causes it to magnetize, forcing the core to lower against the spring, closing the valve.

Application

Normally open vent valves can often be found on main gas manifolds. The main gas manifold may have a vent line to allow excess gas to exhaust to a safe location, often to atmosphere.

When the system is energized, the vent valve is closed, and the safety shut-off valves may open, allowing gas to pass through the system.

If the system loses power, either because of a power failure, or an emergency shut-down, or normal shut-down, the safety shut-off valves close. An excess amount of gas may remain in the manifold, and must be released from the lines in order to safely restart the system.

Because VMRNA is normally open, the loss of power to the system allows any excess gas to safely “vent” to a designated area.

Take Care with Spares

Vent valves and safety shut-off valves can look similar. Be careful! Below is a vent valve VMRNA and a safety shut-off valve VMR. Of course, the label should tell you everything you need to know. In addition, the top of the VMRNA and the top of the VMR are noticeably different. Please take a few extra moments to be certain you don’t mix them up — it’s extremely important!