Solenoid Valve versus Motorized Valve

What is a Solenoid Valve?

  • A solenoid valve is an electrically operated valve that includes a cylinder & a movable electrode.
  • It encompasses an electric wire coil with a movable ferromagnetic core called a plunger at the center of the core. 
  • A Solenoid valve consists of an eccentric spring at its center, & functions on the principle of the law of electromagnetism the magnetic field within the coil is produced by passing a certain amount of electric current through that coil for opening or closing the valve path. 
Sol valve
  • Generally, a solenoid valve consists of an electromagnet to regulate the opening and closing of a fluid passage such as air or oil.
  • The coil gets magnetized by applying supply voltage to generate an electromagnetic field, this makes the plunger move to attract or to repel.
  • When the coil gets energized by voltage an electromagnetic force pushes the plunger in the cylinder for the valve orifice to open or close to control the flow of fluid passing through the valve.
  • The magnet in the solenoid coil is pulled back and enables the piston for upward movement in its housing in case it doesn’t seal against it.
  • The magnetic field strives an upwards force on the plunger for the orifice to open. 
  • When the coil gets energized (when voltage is applied), the plunger opens the obstruction caused for the working fluid to pass through it.
  • When the coil gets de-energized (when voltage is not applied), the spring restores the plunger to its initial position to close the obstruction and restricts the fluid flow through it. 
  • This can be termed as a PLC Digital Output for either to neither turn on nor turn off.
  • Actually, this type of valve requires a higher amount of pressure than that of a ball valve because this valve consists of two springs on either side of the coil that consumes less arm strength or force for operation.
  • The magnetic flux lines are established on a core to increase the induction of the coil when a metallic core is located inside the coil.
  • Usually, these solenoid valves are designed for gases and for clean liquid applications.

What is a Motorized Valve?

  • The name motorized valve implies that the valve operates by using an electrical motor that uses an electrical supply.
  • In a motorized valve, an electric motor is fixed on the top of the valve and connected to the valve stem for proper valve movement for closing and opening of the valve as required.
Motorized valve
  • The operation of the electric motor used to control this valve is quite slow and controlled.
  • When a motor is turned on it opens the throttle valve in a sudden rise boosted and heightened slow way.
  • When a motor is turned off it closes the throttle valve in a sudden drop boosted and heightened slow way.
  • Motorized valves are used in some industrial applications where we require a high degree of control in the case of HVAC systems.
  • The motorized valve permits for proper passage of fluid flow.
  • Generally, this motorized valve can be Analog Output (AO) or Digital Output (DO) from the PLC.
  • A motorized valve provides the controlling action remotely through various systems such as PLCs, DCS, and computer control systems.

Difference between Solenoid Valve & Motorized Valve

Solenoid ValveMotorized Valve
A solenoid valve works by using an electromagnet.A motorized valve functions by using a motor that runs on an electrical supply.
The electromagnet gets activated when a current flows in itIn motorized valve switch or a controller is used to activate an electrical motor
The response time of solenoid valves is very fast like automotive engines compared to motorized valvesThe response time of a motorized valve is very slow compared to solenoid valves. 
Generally, Solenoid valves are more compact compared to motorized valves.Generally, Motorized valves are less      compact compared to solenoid valves.
Solenoid valves can be easily installed in limited space such as in automotive engines but motorized valves do not.Motorized valves require more installation space compared to solenoid valves
Solenoid valves offer quick magnetization & operation in response to the electric current.The operation of the motorized valve is very slow in response to the electric current.
The Solenoid valve offers lower flow rates compared to the motorized valve.Motorized valves offer a higher flow rate case of HVAC systems compared to solenoid valves.
A solenoid valve doesn’t offer a smooth passage for fluid flow due to rapid control. Motorized valve offers precise and accurate control of the fluid.
A solenoid valve offers Digital Output for PLC.Motorized valve offers Digital Output or Analog Output for PLC.
Solenoid valves are suitable only for low-pressure media.A motorized valve can be used for both high-pressure and low-pressure media, 
The Solenoid valve offers quick opening and closing operation within a few seconds.The motorized valve can control the fluid flow more accurately without causing any load to the pipeline.
The solenoid valves are classified into 2-Way, 3-Way, or 4-Way valves.The motorized valves are classified into quarter-turn valves, linear valves, or multi-turn valves.
The Solenoid valve consumes low power compared to the motorized valveThe motorized valve consumes more power compared to the solenoid valve.
Requires more maintenance compared to motorized valveRequires less maintenance compared to the solenoid valve.
Usually, these Solenoid valves are used in small flow occasions with small diameter lines.Usually, these motorized valves are used in large flow occasions with large diameter lines.
Solenoid valves offer high switching speedsMotorized valves offer slow switching speeds.
In this type of valve, the coil gets damaged easily due to poor resistance to voltage shock hence the rate of valve failure is high.The motorized valve is strong and is able to resist voltage shocks, & hence the rate of failure is very low.
Generally, this solenoid valve is applied only for open-loop control. Generally, this motorized valve is applied only for closed-loop control. 
Solenoid Valves are cheaper than motorized valves. Motorized Valves are more expensive than Solenoid valves. 
Installation of the solenoid valve must be always on the horizontal axis.Installation of the motorized valve can be on both the vertical axis & horizontal axis.
A Solenoid valve has a shorter life span compared to a motorized valve.A motorized valve has a higher life span compared to a solenoid valve.

Frequently asked Questions

How does the solenoid valve work?

A Solenoid valve is basically an electromechanically controlled valve that works by the law of electromagnetism using an electromagnet. 

How does a motorized valve work?

The motorized valve works with the help of an electric motor fixed on the top of the valve and connected to the valve stem for proper valve movement.

Can we install a solenoid valve in both the vertical axis & horizontal axis?

No, the solenoid valve is installed only on the horizontal axis

How is the solenoid valve classified?

The solenoid valves are classified into 

  • Two Way Valve
  • Three Way Valve
  • Four-Way Valve

How are motorized valves classified?

The motorized valves are classified into 

  • Quarter-Turn Valves, 
  • Linear Valves. 
  • Multi-Turn Valves.

Related Articles

Back to top button