Benefits of Different Pinch Valve Types - AUTOMATIC VALVE

Pinch valves are ideal for various slurry control applications due to their versatility, flexibility. And ability to handle corrosive and abrasive slurries. Pinch valves are available in different types, including air-operated, manual, hydraulic, electric, manual override, and solenoid pinch valves. Each of these types has its unique features and benefits, which make them suitable for different slurry applications. In this blog post, we will explore the benefits of each type of pinch valve. So you can decide which one is most suitable for your application. Let’s dive in and take a closer look at the advantages of different types of pinch valves.

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I. Air-Operated Pinch Valve

Pinch valves known for their flexibility, durability, and versatility to handle different slurry applications. Air operated pinch valve offer several benefits. Including precise slurry flow regulation, resistance to abrasion and corrosion, minimal maintenance. And no contact between the slurry and internal valve components, which reduces contamination risks. In this section, we will take a more in-depth look at the advantages of the air-operated pinch valve. And learn more about its features and applications.

Minimal maintenance required due to its simple design

An pneumatic pinch valve has several benefits, one being the minimal maintenance required due to its simple design. Since it has no internal moving parts, there is no chance of wear and tear. It makes the valve’s maintenance less costly and infrequent. The valve operates by compressing the rubber sleeve to control the flow of the slurry. It requires minimal adjustment or maintenance. This simplicity of design ensures that the valve is efficient in controlling. The flow of the slurry while minimizing downtime and maintenance costs.

No contact between the slurry and internal valve components, reducing the risk of contamination

Another advantage of the air-operated pinch valve is that there is no contact between the slurry and internal valve components, reducing the risk of contamination. The valve sleeve compresses the slurry and creates a seal between the inlet and outlet. As a result, there is minimal chance of cross-contamination, ensuring that the slurry remains pure. The valve’s simple design eliminates the need for seals and other internal components that can corrode or contaminate the slurry. By preventing contamination, the air-operated pinch valve provides a reliable solution for slurry control. In industries, purity is crucial, such as the food and beverage industry.

Ability to control the slurry flow precisely

An air-operated pinch valve offers precise control over slurry flow, making it ideal for various applications. The valve sleeve, which is made of rubber, is compressed to control the slurry’s flow through the pipe. The valve’s ability to control slurry flow precisely is due to the close tolerances. It between the valve sleeve and the body. By adjusting the air pressure, you can regulate the amount of compression on the valve sleeve. It controls the flow of the slurry through the valve. The valve’s precise flow control ensures that the slurry is delivered at a consistent rate. It reduces production waste and improves process efficiency.

Resistance to abrasion and corrosion

The air-operated pinch valve is resistant to abrasion and corrosion, thanks to its simple yet robust design. The valve’s rubber sleeve is highly resistant to abrasion from slurry and other abrasive materials. It reduces the risk of valve wear and failure. Additionally, the valve’s body is typically made of materials that can resist corrosion from chemicals and other corrosive materials. This resistance to abrasion and corrosion extends the valve’s lifespan while providing reliable performance in harsh environments. With its durability, the air-operated pinch valve is an ideal solution. For slurry control applications in the mining and chemical industries, where abrasive and corrosive materials are commonly transported.

II. Manual Pinch Valve

Manual pinch valve are operated by hand to regulate slurry flow. These valves are highly versatile, and their simplicity makes them ideal for use in various industrial applications. Manual pinch valves offer a range of benefits. It includes the ability to adapt to different flow rates and slurry viscosities, customizable sleeve options, and minimal maintenance requirements. This section will examine the manual pinch valve’s benefits. And how this valve type performs in different slurry control applications.

No external power supply required

One of the critical benefits of manual pinch valves is that they do not require an external power supply. The valve is operated manually by applying pressure to the valve’s body or handwheel. It compresses the rubber sleeve and regulates the slurry’s flow. This feature makes manual pinch valves ideal for remote locations or areas with limited access to electricity. Additionally, manual pinch valves can use as backup valves in case of power outages. It ensures that the slurry flow remains uninterrupted. The absence of external power supply requirements also makes manual pinch valves a more cost-effective solution for slurry control applications.

Versatility and flexibility in adapting to different flow rates and slurry viscosities

Manual pinch valves offer versatility and flexibility in adapting to different flow rates and slurry viscosities. It makes them ideal for different slurry control applications. The valve’s rubber sleeve can be customized to handle various slurry compositions, ranging from low to high concentrations of solids. The valve’s simple yet efficient design allows for easy adjustments to adapt to different flow rates and slurry viscosities. Manual pinch valves are also available in different sizes and configurations to fit different pipe diameters and fluid flow rates. This versatility and flexibility make manual pinch valves an excellent solution for slurry control applications in industries. Such as food and beverage, chemical processing, and mining.

Minimal maintenance required due to its simple design

Manual pinch valves have a simple design that results in minimal maintenance requirements. The valve is composed of a body and a rubber sleeve that can be easily replaced. There are no complex components or external parts that require regular maintenance or repair, reducing downtime and costs. Additionally, manual pinch valves do not require any additional lubrication or cleaning. It makes them a low-maintenance solution for slurry control applications. Thanks to their simple design, manual pinch valves provide reliable slurry flow regulation with minimal maintenance. It makes them the preferred choice in various industries. Such as wastewater treatment, pharmaceutical, and pulp and paper.

III. Electric Pinch Valve

Electric pinch valves are a popular type of control valve that provides precise and efficient slurry flow regulation. These valves operate by an electric motor. They actuates to compress the valve sleeve, controlling the slurry flow through the pipe. Electric pinch valves offer several advantages. Including accurate flow control, reduced energy consumption, and remote control capabilities. In this section, we will take a closer look at the benefits of electric pinch valves. And how they can use in various industrial applications.

Precise flow control with minimal manual adjustments

Electric pinch valves offer precise flow control with minimal manual adjustments, making them ideal for automation in various industrial applications. The valve’s electric motor allows for accurate and repeatable positioning of the valve sleeve. It results in more precise slurry flow control. This feature also reduces the chances of over-compressing or under-compressing the valve sleeve, minimizing errors in the slurry flow regulation. Compared to manual pinch valves, electric pinch valves can provide greater regulation accuracy, improve process efficiency, and reduce waste. Additionally, electric pinch valves can easily integrate into process control systems. It allows for remote operation and monitoring of the valve’s performance without the need for on-site personnel.  Electric valve

Customizable sleeve options to handle different slurry types and concentrations

Electric pinch valves offer customizable sleeve options that can handle different slurry types and concentrations. The valve’s rubber sleeve provides the primary separation barrier between the slurry and the internal valve components. Electric pinch valves can accommodate various sleeve materials, including natural and synthetic rubbers, silicone, and fluoropolymers. Different sleeve durometers and thicknesses can also use to handle different slurry compositions. It includes low to high concentrations of solids and corrosive materials. With customizable sleeve options, electric pinch valves provide flexible slurry control solutions for different industrial applications such as chemical processing, mining, and wastewater treatment.

What are the types of pinch valves?

There are two primary types of pinch valves used in the medical and scientific industries: external and internal. Each has benefits and drawbacks, depending upon its end-use.

How does a pinch valve work?

The core functionality of a pinch valve is a flexible flow path element that is compressed by an external plunger or pinch block. Most pinch valves employed in these industries are actuated using a solenoid, although some manual hand-actuated pinch valves exist, and they operate like a clamp.

What is the difference between internal and external pinch valves?

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Figure 6: General comparison of features between internal and external pinch valves.

External pinch valves are characterized by tubing that can be easily replaced; internal pinch valves are sealed and maintenance-free. The choice of which valve to purchase for a scientific or medical instrument application is dependent upon several factors. Consideration should be given to the internal volume, carryover volume, maintenance, cycle life, and materials. These factors are discussed in greater detail below.

What factors affect pinch valve performance?

The internal volume of flow path components is a frequent design consideration for the medical and scientific industries. Instrument designers focus upon the reduction of expensive reagents, patient sample sizes, and fluid loss during medical treatments. 

The internal volume of a pinch valve, for external and internal styles, is determined by the inner diameter (ID) and length of the tubing. The ID of pinch valve tubing is generally based on the flow capacity required for a given application. Most medical and scientific applications choose a tubing ID of 1.5 mm or less, equating to a flow of less than 50 mL per minute. If the internal volume is a priority, it is important to choose a valve with a total flow restriction that leaves little margin above your pressure drop requirements.

0.020 inch / 0.5 mm

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0.031 (1/32) inch / 0.8 mm 

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0.040 inch / 1.0 mm

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Figure 1: Comparison of volume for a 10cm length of tubing of common inner diameters. 

When the tubing ID is selected, consideration must be given to tubing length. The tubing and pinch block in internal pinch valves are enclosed in the port head and typically offer a minimized tube length—and as such, the lowest internal volume for a given tubing inner diameter. This advantage is particularly noticeable with 3-way valves because the joining point (Y-connector) for an external pinch valve is located externally to the valve.  

What is Carryover Volume?

 

Carryover volume refers to the amount of fluid volume remaining after a valve switches state. For 2-way “on-off” pinch valves, this is usually not a concern; however, for 3-way pinch valves, the volume carried over can mix with other fluids and is wasted when it is flushed out. Therefore, minimizing this volume is very important. Internal pinch valves offer a major benefit when carryover volume is a consideration because the volume between the pinch point and Y-shaped combination point is minimized.  

What is the life cycle of pinch valves?

Design considerations for medical or scientific instruments focus heavily on maintenance requirements and costs. When these factors are a prime concern, the internal pinch valve is the better choice. These valves are typically rated to 5 million or more cycles prior to replacement. In comparison, external pinch valves typically require tubing replacement every 200,000 to 500,000 cycles, although the solenoid actuators have similar life ratings to that of the internal pinch valves. 

The difference between internal and external pinch valve tubing life can be explained by examining the properties of common tubing materials. Inexpensive silicone and flexible PVC tubing, normally used in external pinch valves, wears out easily and must be replaced frequently. Elastomeric tubing materials such as EPDM or the fluoroelastomer FKM commonly used in internal pinch valves offer life ratings an order of magnitude better—with a trade-off of slightly higher upfront costs.  

Are Pinch Valves useful for Medical Devices?

The stark difference in cycle life (driven by the choice of material) is a key determinant in the selection of a pinch valve for a specific application. External pinch valves are best used in applications where flow path replacement is a requirement, particularly for in-vivo medical applications. For example, dialysis machines frequently replace tubing used to carry blood to eliminate cross-contamination risk. An internal pinch valve—with its maintenance-free design—is a better choice for in-vitro diagnostic applications where a cleaning solution can be used between patient samples.  

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Figure 5: General Dynamic Properties of Common Pinch Valve Tubing Materials 

What material should you get for pinch valve tubing?

A critical consideration in the selection of pinch valves is the materials used in the flow path. External pinch valves feature a single wetted material: the pinch tubing. The available tubing options vary considerably; the choice of tubing is based on compatibility with biological fluids and organic solvents. It is, therefore, important to perform tests for each application. Tubing connectors need to be selected and separately qualified. Internal pinch valves—with integrated tubing connectors such as hose barbs or threaded fittings—typically have more than one wetted material. These materials are selected for compatibility with a wide variety of applications because they are much more difficult to adjust. Therefore, compatibility issues are rare.

when should I use a pinch valve?

The selection of internal or external pinch valves for applications such as analytical chemistry, diagnostics, medical equipment, or next-generation sequencing, must be carefully examined. In general, internal pinch valves are the best choice when low internal volume, low carryover volume, and long life are important factors. External pinch valves are a great solution for applications where easy tubing replacement is a desirable attribute. Both valve types offer clean flow paths, relatively low internal volumes (as compared to other types of valves), and excellent compatibility with fluids commonly used in the medical and scientific industries.

Need a Pinch Valve for your application?

Xover® is a breakthrough in quick and easy flow selection with its innovative pinch-tube design and low carryover volume. This component combines the flow path of a pinch valve with the versatile, maintenance-free performance of a chemically inert isolation valve to power critical applications in high-tech medical and scientific instruments. Learn more about Xover solenoid valves.

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Benefits of Different Pinch Valve Types - AUTOMATIC VALVE

Selecting the Best Pinch Valve for Your Application