Solenoid Valve
All Types of Solenoid Valves We Offer
A solenoid valve is an electromagnetically operated device that controls the flow of liquids or gases by opening or closing when an electric current is applied. Finding the right solenoid valve for your application is crucial for efficient fluid control. At KUHNWAY, we provide a wide range of high-quality water solenoid valves and specialized options designed for various pressure, temperature, and fluid types. Here’s an overview of our key sol valve series:
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MD Series – Direct-Acting Diaphragm Solenoid Valves
Designed for air, water, and light oil, these valves offer fast opening and closing speeds and can operate at zero pressure differential with larger flow openings. Available with maximum pressure ratings of 10, 15, or 20 kgf/cm², they suit various pressure conditions. The diaphragm options include NBR, EPDM, and VITON, while the body materials are bronze, SUS304, and SUS316, ensuring compatibility with different fluid media.
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MT Series – Pilot-Operated Piston Solenoid Valves
Engineered for steam and heavy oil applications, these valves feature a dual-piston ring and guide rod design for enhanced durability and precise operation. The stainless steel guide seat ensures smooth performance while minimizing flow restrictions. They withstand temperatures up to 200°C and are available with maximum pressure options of 10, 16 (for steam), and 20 kgf/cm², making them ideal for high-temperature and high-pressure systems.
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BMF Series – Large-Diameter Pilot-Operated Solenoid Valves
Built for high-flow applications, these valves include a manual override knob, allowing operation without power when needed. The valve body is available in threaded or flanged connections, with flange sizes ranging from 2" to 16" to accommodate different pipe diameters. Material choices include cast iron, bronze, graphite cast iron, SUS304, and SUS316, making them suitable for a wide range of fluid media and industrial applications.
Our solenoid valve products are also available in normally closed, normally open, and explosion-proof options, catering to a broad range of applications. Whether you need a water solenoid valve, steam control, or a high-flow system, we have the perfect solution for you. Contact us today to find the right solenoid valve for your needs!
A normally closed solenoid valve stays closed when de-energized, blocking the flow. When energized, the coil creates a magnetic field, lifting the plunger to open the valve and allow flow. When power is cut, the spring returns it to the closed position, stopping the flow automatically.
A normally open solenoid valve allows flow when de-energized and closes when energized. It’s ideal for continuous flow applications like cooling and drainage systems and ensures fail-safe operation by opening during power loss.
An explosion-proof solenoid valve is built for flammable and hazardous environments, such as petrochemicals, natural gas, and pharmaceuticals. Its sealed housing prevents sparks or heat from igniting explosive gases or dust. Designed to meet strict safety standards, it ensures safe operation in high-risk areas by eliminating ignition risks.
How to Order Solenoid Valve from KUHNWAY
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Contact Us – Visit our Contact Us page or email us to discuss solenoid valve specifications, availability, and pricing.
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Confirm Your Order – Once details are finalized, submit your order via email.
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Make Payment – Transfer payment to the account provided in our confirmation email.
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Arrange Shipping – Choose between sea freight or air freight for delivery.
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Receive Your Solenoid Valves – We’ll ship your order promptly and provide tracking details.
Need assistance? Contact us anytime for expert support!
How to Choose the Right Solenoid Valve?
Selecting the correct solenoid valve involves several crucial considerations to ensure optimal performance and reliability for your specific application. Below are the main points to help you find the best solenoid valve for your needs.
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Materials and Medium
The material of the solenoid valve affects its durability, corrosion resistance, and compatibility with the fluid or gas it controls. Choosing the wrong material can lead to premature wear, leaks, or even system failure, reducing efficiency and increasing maintenance costs.
Stainless steel is strong and highly resistant to corrosion, making it a top choice for food processing and chemical plants. However, it can corrode in environments with high chloride levels. Brass is a cost-effective, corrosion-resistant option, commonly used for water supply systems and neutral fluids. However, they are less suitable for seawater or distilled water.
Bronze is tougher than brass and resists cracking, making it useful in plumbing and industrial applications. Cast iron is extremely strong but brittle, so it is mostly found in heavy-duty industrial systems. If you’re working with aggressive chemicals, PTFE (polytetrafluoroethylene) is a great choice, as it is highly resistant to corrosion and works in high-purity and chemical handling applications.
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Pressure and Temperature Range
A solenoid valve must withstand the pressure and temperature extremes of its application. Exceeding its limits can cause failures and leaks. Always check the pressure rating (PSI or bar) to ensure the valve can handle your system’s requirements.
For instance, a hydraulic system requires a valve rated for high pressures to prevent damage. Temperature also plays a big role. Higher temperatures can change fluid properties, affecting flow rate. If you’re working with steam systems, opt for materials like stainless steel or high-temperature polymers that can handle extreme heat.
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Response Time
Response time matters when fast actuation is needed. Direct-acting solenoid valves respond the quickest—within milliseconds—making them perfect for emergency shut-off systems where speed is crucial.
Indirect-acting (pilot-operated) valves are slower but better suited for handling large fluid volumes. These are used in fuel flow control in aircraft, where precision is more important than speed. Semi-direct-acting valves offer a balance, responding faster than pilot-operated valves while allowing higher flow rates, making them great for HVAC and industrial automation where moderate speed and flow are needed.
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Circuit Function
The way a solenoid valve controls fluid flow depends on its circuit function.
2-way solenoid valves have one inlet and one outlet, simply opening or closing to control flow. These are common in basic water dispensing systems. 3-way solenoid valves have three ports, allowing for alternating flow paths. They are ideal for controlling single-acting pneumatic cylinders.
4-way solenoid valves handle more complex fluid movements with four ports. These are mostly used in hydraulic and pneumatic systems where flow needs to be directed to different outputs, such as in airplane control surfaces.
5-way solenoid valves have five ports—one inlet, two outlets, and two exhausts—designed for controlling double-acting cylinders in pneumatic systems. They direct air to extend or retract the cylinder by alternating airflow between the two outlets. This makes them ideal for automated machinery and robotics requiring precise bidirectional movement.
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Certification
Certifications ensure a solenoid valve meets safety and regulatory standards. UL (Underwriters Laboratories) certification means the valve has been tested for safety and reliability. IP ratings indicate resistance to dust and water—for example, an IP67-rated valve can handle outdoor conditions and brief water immersion.
Other certifications, like CE (European Union), CSA (Canada), FM Approval (fire protection), and NSF (drinking water safety), ensure the valve is safe for specific industries, including fire safety, gas handling, and food production. For explosion-proof solenoid valves, compliance with ATEX and IECEx standards is crucial to ensure safe operation in hazardous areas.
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Voltage and Coil
Solenoid valves operate using either Alternating Current (AC) or Direct Current (DC). AC coils are commonly used in industrial applications and are known for their rapid response times. However, they can generate heat and may produce a buzzing noise due to the alternating nature of the current. DC coils, on the other hand, provide a steady magnetic field, resulting in quieter operation and more precise control. They are often preferred in applications where noise reduction and accuracy are critical. It's essential to match the coil type with your power supply to ensure efficient and safe operation.
For fountains, irrigation systems, or outdoor installations where moisture is a concern, choose a solenoid valve with a waterproof coil. These coils are sealed with epoxy resin to prevent water ingress and enhance durability. Many are rated IP68, meaning they are dust-tight and can withstand continuous submersion, ensuring reliable performance in wet conditions.
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Circulation Volume
Understanding the required flow rate of your system is vital when choosing a solenoid valve. Flow rate is typically measured in units like liters per minute (L/min) or gallons per minute (GPM). Selecting a valve with an appropriate circulation volume ensures that the valve can handle the desired flow without causing excessive pressure drop or restricting the system's performance. Manufacturers often provide CV values to help you select the right valve size for your application. Choosing a valve with a CV that matches your system's requirements ensures efficient and reliable operation.
What is a Solenoid Valve and Its Functions?
A solenoid valve is an electromechanical valve that uses an electromagnetic actuator (solenoid) to control fluid flow. The solenoid converts electrical energy into mechanical motion, using a magnetic field to move a plunger or core, which either opens or closes the valve. In simple terms, when the solenoid is energized, the valve changes its state—either allowing fluid to pass through or stopping it. These valves function in a binary manner, fully open or fully closed without intermediate positions.
Solenoid valves are widely used in various applications, such as controlling water flow in dishwashers, managing air in pneumatic systems, and regulating fuel in engines. Their ability to provide quick, remote, and precise control makes them essential components in many automated systems.
Components of Solenoid Valve
A solenoid valve has two primary components: the solenoid and the valve body. The solenoid is an actuator that uses an electromagnetic coil, while the valve body contains the parts that come into contact with the fluid. The specific parts of the solenoid may vary, but the valve body components are generally consistent, although their design and material may differ.
The following are the general components of a solenoid valve and their functions:
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Coil (A)
The coil is made of insulated copper wire wound around the outer part of the magnetic core tube. When energized, the coil generates a magnetic field that drives the movement of the plunger, thereby controlling the opening and closing of the solenoid valve. -
Spring (B) and Plunger (C)
The plunger (or piston) is the core actuating component of the solenoid valve. It is typically cylindrical and made of ferromagnetic material, located inside the solenoid tube. The spring provides initial preload force. In a normally closed valve, the spring pushes the plunger downward to close the orifice; in a normally open valve, it supports the plunger upward, keeping the valve open when de-energized. -
Diaphragm Return Spring (D)
The diaphragm return spring connects the diaphragm to the plunger. It helps return the diaphragm to its original position and stabilizes the valve’s operation. -
Valve Cover and Body (E)
The valve cover protects the upper internal components. The valve body is the main pressure-bearing part, housing the diaphragm, inlet and outlet ports, and flow passages. It is the core structure for controlling fluid flow. -
Solenoid Tube (F)
The solenoid tube is a hollow guiding component that directs the up-and-down motion of the plunger. Any defects or accumulation of debris inside the tube may cause the plunger to stick, overheat, or lead to valve failure. -
Shading Ring (G)
The shading ring is a single or a few turns of a conductive material (such as copper or aluminum). It creates a phase shift in the magnetic field, reducing noise and vibration during AC operation and allowing for smoother valve performance. -
Seal (H)
The seal is responsible for closing or opening the orifice, preventing medium leakage. In normally closed valves, when energized, the plunger moves upward, lifting the seal and opening the orifice. In normally open valves, the plunger moves downward to close the orifice. -
Diaphragm and Pilot Hole (I)
In diaphragm-type solenoid valves, the diaphragm isolates the electromagnetic components from the fluid. The pilot hole provides pressure balancing, reducing the force required to open the diaphragm. This is a key design feature in pilot-operated solenoid valves. -
Orifice (J)
The orifice connects the inlet and outlet ports. The plunger opens or closes this orifice to regulate the flow of fluid through the valve. Depending on the valve design, there may be one or more orifices to suit its operating mechanism.
Solenoid Valve vs. Motor Valve
Solenoid valves and motor valves both rely on electrical energy to operate and are widely used in automation systems. However, their working principles, control methods, applications, and adaptability to different operating conditions vary significantly.
Solenoid valves use an electromagnetic coil to quickly switch between open and closed states, relying on digital (DO) control. In contrast, motor valves use a reversible motor to regulate the valve core, allowing for analog (AI) control, and enabling precise flow adjustment.
Solenoid valves are ideal for small pipelines (≤DN50), offering fast switching, low power consumption, and tight sealing. However, they only support on/off control, require clean fluids, and can only handle one-way flow. Also, most solenoid valves require a minimum pressure difference to function and cannot remain powered indefinitely.
Motor valves, designed for larger pipelines and air systems, provide adjustable flow control, work with impure fluids, and support bidirectional flow. Unlike solenoid valves, motor valves do not require a pressure differential and can stay powered without overheating. However, they operate more slowly and need additional components for automatic reset upon power failure.
To sum up, solenoid valves are best for quick-switching, low-pressure applications, while motor valves excel in large-scale flow regulation where precise control is needed.
Benefits of Solenoid Valve
Solenoid valves offer a range of benefits that make them ideal for various uses. Their automation-friendly design, fast response times, and energy efficiency make them a top choice for fluid control. Let’s break down why they’re so effective.
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Remote Operation
One of the biggest advantages of solenoid valves is that they can be controlled remotely. This makes them perfect for hard-to-reach or hazardous environments, such as handling toxic, high-temperature, or high-pressure fluids. Instead of manual adjustments, operators can control flow with a simple electrical signal.
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Fast Response Times
Speed is critical in many industrial applications, and solenoid valves excel in this area. They can open and close in milliseconds, ensuring instant fluid control. This is especially important in automated manufacturing, emergency shut-off systems, and pneumatic operations where every second counts.
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Low Energy Consumption
Solenoid valves are designed to be energy-efficient. Some models can hold their position with minimal power consumption, reducing operating costs and making them ideal for long-term industrial use. This is beneficial for battery-operated devices, energy-conscious manufacturing plants, and HVAC systems.
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Versatility
Solenoid valves come in a variety of configurations, making them highly adaptable. They support both AC and DC voltages, meaning they can be integrated into different electrical systems with ease. Whether you need a valve for water systems, gas pipelines, or high-pressure applications, there’s a solenoid valve that fits the job.
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Enhanced Safety
Safety is a priority in industries dealing with corrosive, toxic, or high-pressure substances. Solenoid valves use an electromagnetic seal, eliminating the need for dynamic sealing, which reduces leak risks. Their precise control also makes them ideal for high-risk environments like chemical plants and refineries.
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Cost-Effective Maintenance
Solenoid valves have a simple design, which makes them easy to install and maintain. With fewer moving parts, they experience less wear and tear, meaning lower maintenance costs over time. This makes them a great long-term investment for businesses.
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Seamless Network Connectivity
Because solenoid valves operate using electromechanical switch signals, they can be integrated into computer-controlled systems. This is crucial for automated manufacturing, smart irrigation systems, and process industries that rely on digital monitoring and control.
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Compact Design
Space-saving is essential in modern system design. Solenoid valves have a compact profile and lightweight build, making them ideal for tight spaces like medical devices, industrial automation setups, and portable machinery.
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Precise Flow Control
Accuracy matters, especially in industries like healthcare, food processing, and manufacturing. Solenoid valves offer precise flow regulation, ensuring exact amounts of fluid or gas are delivered, preventing waste, and improving process consistency.
Types of Solenoid Valve
Solenoid valves can be classified based on their mode of operation, which determines how they control fluid flow. The main types include direct-acting, semi-direct-acting, and pilot-operated (internally and externally piloted) solenoid valves. Each type functions differently, offering unique benefits depending on system requirements.
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Direct-acting
Direct-acting solenoid valves operate without relying on external pressure. When the coil is energized, the electromagnetic force lifts the plunger, opening the valve to allow fluid or gas to flow. Once de-energized, a spring forces the plunger back into place, closing the valve.
This type of solenoid valve is ideal for low-pressure systems and applications requiring instant response and fast operation, as there is no pressure delay. They are commonly used in fuel injection systems, refrigeration units, and medical devices where precise and immediate flow control is necessary. Direct-acting solenoid valves have the fastest operation, are reliable, and have a compact design.
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Semi-direct-acting
Semi-direct acting solenoid valves, also known as assisted-lift solenoid valves, combine the advantages of direct acting and indirect acting designs. Unlike pure direct acting valves, the solenoid plunger is directly connected to the diaphragm, allowing the valve to operate at zero pressure while using system pressure to handle higher flows.
When the solenoid is energized, the plunger lifts, opening both the primary and secondary orifices. This action creates a pressure drop, further lifting the diaphragm, allowing fluid to flow smoothly. This design makes the semi-direct acting valve highly efficient over a wide pressure range, providing faster response times and higher flow capabilities than standard direct acting valves.
The ability to operate without minimum pressure requirements while still accommodating high flow rates makes it ideal for steam systems, compressed air networks and HVAC applications. These features allow it to bridge the gap between low pressure precision control and high flow industrial applications, making it a versatile choice in automated fluid control systems.
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Piston-Type vs. Diaphragm-Type
The semi-direct-acting solenoid valves can be further classified into piston-type (like our MK10~25 series) and diaphragm-type (like our MA, MD series). Here’s a comparison of their differences:
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Piston-Type: These use a piston mechanism to control fluid flow, offering high-pressure resistance and longer durability. They are commonly used in industrial applications requiring high operating pressures and heavy-duty performance.
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Diaphragm-Type: These use a flexible diaphragm to open and close the valve. They are ideal for low to medium-pressure applications and work well with clean or slightly contaminated fluids. These valves are often used in water systems, gas control, and HVAC applications due to their smooth operation and lower maintenance requirements.
Note that diaphragm materials can vary in chemical resistance, temperature tolerance, and application suitability. Let’s look at some common options:
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NBR (Nitrile Rubber): Best for oils, fuels, and water but has limited heat and chemical resistance.
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EPDM: Excels in hot water, steam, and mild chemicals, making it ideal for HVAC and food processing, though it is not compatible with oils.
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VITON (FKM): Offers superior resistance to acids, fuels, and high temperatures, making it perfect for chemical applications, but it performs poorly in hot water and steam.
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Teflon (PTFE): With exceptional chemical and temperature resistance, suitable for corrosive fluids, though it is less flexible than rubber-based diaphragms.
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Pilot-operated (Internally and externally)
Pilot-operated solenoid valves, also known as indirect-acting or servo-assisted valves, rely on a pressure differential rather than the solenoid’s electromagnetic force alone to control fluid flow. It normally needs a minimum of 0.5 bar. Instead of directly opening or closing the main valve, the solenoid controls a smaller pilot valve, which in turn regulates the pressure in the main chamber. This design significantly reduces the energy needed to actuate large valves, making it particularly effective for high-pressure applications where a direct-acting solenoid valve would require an impractically large and powerful coil.
There are 2 subtypes: internally-piloted and externally-piloted.
Internally-piloted solenoid valves utilize the system’s fluid pressure to control the main valve. In the closed position, pressure builds up on both sides of a diaphragm through a bleed orifice, keeping the valve shut due to the larger surface area on top. When the solenoid is energized, the pilot valve opens, releasing pressure from the upper chamber and creating an imbalance that forces the diaphragm upward, opening the main valve for fluid flow.
Externally piloted solenoid valves operate similarly but rely on an external pressure source instead of system pressure. These valves include an additional port that connects to a separate fluid circuit, which actuates the diaphragm or piston. This setup allows them to function even in low-pressure or vacuum environments, where system pressure alone wouldn’t be sufficient for actuation.
Both internally and externally piloted solenoid valves are designed to handle high-flow and high-pressure applications efficiently. Since the main actuating force comes from the pressure differential rather than the solenoid coil itself, these valves can control large fluid volumes using relatively small solenoids. This feature makes them energy-efficient, cost-effective, and reliable for process automation, HVAC systems, chemical processing, and water distribution networks. Their ability to control large flows with minimal energy input makes them a preferred choice for large-scale industrial and commercial applications.
Applications of Solenoid Valve
Solenoid valves are the silent workhorses behind many automated systems, ensuring precise fluid and gas control. From high-tech medical devices to industrial automation, these electromechanical valves play a crucial role in keeping systems running smoothly. Let’s explore their impact and applications across various industries.
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Automation & Manufacturing
In industrial settings, solenoid valves control compressed air and hydraulic fluids to operate robotic arms, conveyor belts, and assembly lines. Their fast response time and remote operation make them essential for efficient manufacturing. Instead of manually turning valves, these automated systems improve speed, precision, and safety in production plants.
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Medical & Healthcare
In hospitals, solenoid valves regulate oxygen and medication flow in devices like ventilators, dialysis machines, and anesthesia systems. Their precise control ensures patients receive the exact amount of gas or liquid needed. Plus, their compact and reliable design makes them ideal for critical life-support systems.
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HVAC & Refrigeration
Ever adjusted an air conditioner? Solenoid valves control refrigerants to regulate cooling and heating in HVAC systems. They open and close automatically to maintain temperature balance, making buildings energy-efficient while ensuring comfort.
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Water Management & Irrigation
From automated sprinkler systems to large-scale water treatment plants, solenoid valves help control water flow with precision. They enable automated irrigation, ensure safe drinking water processing, and help manage sewage treatment efficiently. Their fast on/off response prevents water wastage and supports conservation efforts.
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Food & Beverage Industry
In soda dispensers, dairy processing, and food packaging, solenoid valves handle liquids and gases with hygienic and corrosion-resistant designs. They allow precise portion control, ensuring products meet food safety standards while maintaining efficiency in high-speed production lines.
KUHNWAY – Your Trusted Supplier for High-Quality Solenoid Valves
Solenoid valves are essential components in fluid control systems, ensuring precise, automated flow regulation for a wide range of applications. From water distribution and HVAC systems to industrial automation and chemical processing, solenoid valves provide efficiency, reliability, and safety in even the most demanding environments. As a leading solenoid valve manufacturer and supplier, KUHNWAY is committed to delivering high-performance solutions tailored to your needs.
Our MD Series Direct-Acting Diaphragm Solenoid Valves provide fast response times and zero-pressure differential operation, making them perfect for air, water, and light oil systems. For high-temperature and high-pressure applications, the MT Series Pilot-Operated Piston Solenoid Valves offer durability and precise control, handling steam and heavy oil at temperatures up to 200°C. For large-flow systems, our BMF Series Large-Diameter Pilot-Operated Solenoid Valves support manual override and flexible connections, with flange sizes from 2" to 16", making them ideal for industrial and high-volume applications.
At KUHNWAY, we combine advanced engineering with exceptional performance to provide the best valve solutions for any application. Contact us today to find the perfect solenoid valve for your system and enhance your operational efficiency!