Tuesday, August 4, 2009

Solenoid Valves

Solenoid Valves come in all shapes and sizes and all means of operation. For automation needs, the solenoid valve is the valve of choice.

This will be a brief discussion of the common solenoid valve used in industry today.

A solenoid valve is a combination of a valve body the allows a media to flow through it, water, air, oil and a coil that with a voltage applied energizes a magnetic coil to move a plunger that allows the valve to either open or close. Solenoid valves can be signaled by sensors within a plant via an electrical signal thus an operation can then be achieved.

Solenoid valves come in three basic styles, two way, three way and four way valves. The Two way valves have two ports, an inlet and outlet. The valves can be either normally open or normally closed.
Normally Closed is the more common style as it requires power to open and will close in a power failure.

Three way solenoid valves are designed for operating cylinders, air operated control valves and in some cases diverting flow between two directions. 3-way valves can come in normally open, normally closed and universal operation. Universal operation requires a direct acting valve, normally a small size valve, 1/8, 1/4 or 3/8 ports.

Four way valves are also designed for operating cylinders and valves and can have two solenoids on them, one for each of the two operations.

The valves can come in different body materials, stainless steel, brass, PVC, Teflon or other. The most common is brass and stainless steel. Seals can be Nitrile, viton, neoprene, or Teflon to name the most common. The different seals have different temperature properties and corrosion resistance.

Most solenoid valves come with a NEMA 4X coil, good for washdown and submersion in water. Also available are nema 7/9 or explosion proof and DIN style connections.

Anderson-Bolds stocks valves from Parker and ASCO. We can also provide specialty valves from Valcor.