Solenoid Operated Valve

Table of Contents

Solenoid operated valve works on electromagnetic principle. it comes with different types and size according process demand. basically solenoid operated valves use to control on off action.

Basic principle:- Electromagnetic Induction

Electromagnetic Induction: – When the current flows through a current carrying coil and a soft iron piece are placed between it became magnetized and acts as magnet.

Helix Law: – According to Helix law if D.C. current flows through a solenoid then iron piece placed between it gets the property of magnet which can be shows by right angle law.

Definition: – Solenoid operated valve is a electromechanically operated valve. The valve is controlled by an electric current. Though a solenoid, in case of two port valve the flow switched between ‘ON’ or ‘OFF’. But in case of three way valve the flow switched between input output and exhaust.

Solenoid: – A solenoid is a coil wound into a tightly packed helix. The terms were found by French physicist ANORE-MARIE- AMPERE in (1775-1836).

A solenoid is a coil of wire carrying current that acts like a magnet when the current pass through it. The term may refer to variety of transducer device that convert a energy into linear motion.

Solenoid valve are used to control element in fields. There used are to shut off, release, close, distributed, or mix fluid.

The following are used in SOV.

1. Valve Body

2. Input Port

3. Output Port

4. Coil

5. Coil winding

6. Lead wiring

7. Plunger

8. Spring

9. Orifice

How does a solenoid work: -

The media constructed by the solenoid valve enters the valve through the inlet port (port 2 as mentioned above) the media must flow through closed and opened by the plunger.

The valve picture mentioned above is normally closed valve use a spring which pushes the plunger tip against the opening of the orifice. The sealing material at the tip of the plunger keeps the media from entering the orifice, until the plunger lifted up by an electromagnetic field.

Solenoid offers fast and safe switching, high reliability, long service life, good medium capability of the materials used low control power and compact design.

Operation of SOV

2/2 way or 2 way SOV:-

For example a two way valve has two ports if the valve is open. The two ports are connected and fluid flow through two ports; if the valve is closed then port is isolated.

If the valve is open and the solenoid is energised then the term is called normally open. When the valve is closed and the solenoid is not energised the term is called normally closed.

The above SOV are two way SOV and also known 2/2 SOV.

3/2 way SOV:-

In 3 way SOV in normally closed condition the output is connect between output and exhaust but when coil is energized then the output is connect with input.

In normally open condition the output is connected between input/output but when coil is energised the output will be connected between output and input.

4/2 way SOV:-

In 4 way solenoid valve, In normally closed condition first the input connect from output2 and output1 is connect with exhaust. When the coil energised I/p will connect with o/p1 and o/p2 will connect with exhaust.

In normally open condition, I/P connect with O/P1 and O/P2 connects with exhaust. When coil became energised I/P will connect with O/P2 and O/P1 will connect with exhaust.

5/2 way SOV :-

This SOV are used where double acting process are required. In double acting type actuator 5/2 way SOV are used. There 1 I/P, 2 O/P, 2 Exh.

In normally closed condition I/P is connect with O/P2 and O/P1 is connect with exhaust1. When the coil became energised I/P will connect with O/P1 and O/P2 will connect with exhaust2

In normally open condition. When the coil is de-energised I/P is connect with O/P1 and O/P2 is connect with Exhaust2. When coil became energised I/P connect with O/P2 and O/P1 will connect with Exhaust1.