Control Valves Modulation Vs On-Off Type, The Difference?

Control Valves Modulation Vs On-Off

You want your business to be as competitive as possible in this rapidly-changing environment. You can’t afford unnecessary downtime or inefficiencies.

Using the right control valves helps you optimize your flow control system. Is it time for a new on-off or modulation control valve?

On-off and modulating valves give you different levels of control over your fluid control system. 

On-Off Control Valves

An on-off valve is either open or closed. It allows unrestricted flow or prevents the flow entirely. On-off valves are also called stop, shutoff, or isolation valves.

Uses for on-off valves include:

• Routing process fluid to different locations
• Starting and stopping processes
• Emergency shutoff

An on-off valve can be a backup for a modulating valve.

Modulating Control Valves

A modulating control valve gives you precise control over the flow rate in your system.

The valve actuator allows the right flow rate by using feedback and control signals to open and close the valve. The digital positioning system compares the physical position of the shaft to the desired position. If the valve isn’t in the correct position, the control unit will open or close the valve to reach the right position.

Modulating control valves let you position the valve anywhere between fully open and fully closed, which is typically between 0º and 90º. Regulating the flow rate lets you control other system variables like temperature, liquid level, or concentration.

Modulating valves are ideal for applications that need a high level of precision, such as:

• Power plants
• Wastewater treatment
• HVAC systems
• Irrigation systems

A modulating valve can be more energy-efficient than a frequent on-off action.

Hotowell would provide you both kinds in different models, contact us for more information.

Kelly Tong

Whatsapp/skype: +86 153 5987 4486