A pinch valve is a type of control valve that uses the pinching effect to restrict fluid flow. It has three basic types: Mechanically pinched, Enclosed-body, and Normally closed. To better understand these types of valves, read on. Listed below are a few examples. Each has its pros and cons, and is useful for a variety of applications.
The mechanically pinched pinch valve is a type of valve used to control the flow of fluids. Its design features a molded sleeve made of rubber or synthetic material that includes the pinching mechanism. The rest of the valve is insulated from the media. The body of the valve has reinforced fabric around the pinching mechanism. The valve’s liner has smooth walls that minimize turbulence and line vibration and provide bubble-tight shutoff.
A mechanically pinched pinch valve is a specialized valve that closes a tube. It has a linear actuator that moves a pointer that engages the tube. When the valve is open, the pointer is parallel to the tube, and when closed, it follows a perpendicular path.
An enclosed-body pinch valve closes by means of a rubber sleeve inside its main body. Air pressure travels through the valve’s nipple on the outer body and pushes the sleeve into a tight seal. These valves are typically the most expensive and are used in more intensive applications.
A pinch valve’s body is made from a molded sleeve of rubber or synthetic material that encloses the pinching mechanism. The rest of the operating parts are external to the valve and do not come into contact with the media. The body is reinforced with fabric for added strength, and the liner is smooth, minimizing line vibration and turbulence. A pinch valve can be fitted with electric, hydraulic, or pneumatic actuators.
An enclosed-body pinch valve has three primary parts: the stem, internal sleeve, and main housing. The internal sleeve is made from a flexible plastic or rubber material and must have good abrasion resistance. It also must be able to operate in the required pressure differentials.
A normally closed pinch valve closes the flow of liquid through a pipe. It incorporates a spring and a solenoid actuator to close the pinch elements. These valves are available in a two-way or three-way configuration. Three-way valves have two flow paths, one normally closed and one normally open. They are available in fully energized and de-energized states. The PPS plunger provides chemical resistance.
Normally closed pinch valves are ideal for a variety of applications that top article require low-pressure applications. They can handle a wide variety of media, and the resilient diaphragm is easily replaced on-site. Normally closed pinch valves come with a flanged design for ease of installation and maintenance.
A normally closed pinch valve has a spring element that pushes the pinch element closed during normal operation. This valve then prevents fluid flow until it is reset. Normally closed pinch valves are best used in applications where the operating pressure is less than the control pressure.