Medical Solenoid Valve Applications in Modern Equipment

Medical Solenoid Valve Selection Guide for OEM Engineer

Medical Solenoid Valve Design Guide for Medical Equipment

Medical Solenoid Valve Features for Precise Fluid Control

Medical Solenoid Valve for Diagnostic Equipment Guide

Medical Solenoid Valve for Laboratory Equipment Control

Showing Slide 1 of 6

WL2253 Medical Solenoid Valve Types and Industrial OEM Guide

A medical solenoid valve enables quick and controllable switching of air, gas, water, or other compatible liquids in medical equipment. With this compact electromagnetic valve design, automated systems can control liquid paths automatically. In the case of using medical valves in OEM equipment, its performance parameters have to be matched to the pressure, flow rate, voltage, duty cycle, installation space, leakage rate, and environment. Designers can choose the type of the valve to be normally open or normally closed, 2-way or 3-way, direct acting, and many others depending on equipment design. Medical solenoid valves can improve automation, repeatability, response time, and reliability of your system. OEM customization can include coil voltage, port arrangement, body and sealing material, dimensions, electrical features, and mountings.

Get A Free Quote

PDF Download

Custom Medical Solenoid Valve Product Overview

A typical design of the medical solenoid valve includes an electromagnetic coil, a magnetic circuit, plunger, valve body, sealing members, return spring and fluid ports. When the electric current is applied to the coil, it acts on the plunger changing the fluid path. This enables to control flow on/off and routing within larger medical system. Valve configurations are determined by the application and may include normally open or normally closed operation, 2 way or 3 way configuration, various orifices, ports, voltages, materials and sealing systems. In case of OEM projects the standard valve can be modified or redesigned according to installation dimensions, electrical characteristics, performance and connectors.

Working Principle of the Medical Solenoid Valve

Medical solenoid valve is an electro-mechanical device that converts electrical current into mechanical movement for controlling the liquid or gas flow.

Step 1. Electric Current

The equipment controller sends the electrical current to the coil.

Step 2. Magnetic Field Creation

Electric current in the coil creates a magnetic field.

Step 3. Plunger Shift

Magnetic force moves the internal plunger against the mechanical force, such as the return spring.

Step 4. Change in Flow Path

Movement of the plunger opens, closes, or switches the internal flow path.

Step 5. Controlling the Flow

The valve starts or stops or redirects the flow of the required medium as per the equipment control logic.

Step 6. Disabling the Valve

When the electric current is stopped, the magnetic field disappears. A spring-return design uses the spring for returning the plunger to its initial position.

The working process of the valve depends on the design of the valve, which may be normally open, normally closed, 2-way, 3-way, direct acting, or many others.

Key Features of the Medical Solenoid Valve

Medical solenoid valves are designed for specific control of liquid or gas flow. Key features are compact design, quick response, controllable flow, minimal leakage, low power consumption, and reliable electromagnetic actuation. Depending on equipment design, manufacturers can produce normally open or normally closed valves, 2-way or 3-way flow paths, and many other ports.

Materials and sealing systems have to be chosen in accordance with the medium to be controlled, pressure, temperature, cleaning process, and environment. OEM customization of the valve can include coil voltage, resistance, power consumption, connector type, mounting dimensions, orifice size, body material, and sealing material. In the case of complex equipment, buyers should also pay attention to cycle life, response time, thermal performance, electrical safety, dimensions, and production quality control.

Medical Solenoid Valve Product Video

Medical Solenoid Valve Product Detailed Display

Custom Medical Solenoid Valve Product Feature Overview

Custom Medical Solenoid Valve Working Principle Explained

Custom Medical Solenoid Valve OEM Procedure

Medical Solenoid Valve Performance & System Integration

Medical Solenoid Valve Quality Assurance Guide

Compact Medical Solenoid Valve Buyer Checklist

Custom Medical Solenoid Valve Technical Datasheet

The Different Types of Medical Solenoid Valves Explained

There are many varieties of medical solenoid valves, and the choice of the valve depends on the equipment’s fluid path, control logic, pressure, flow, installation space, and safety requirements. Knowing the difference between valve types can help OEM engineers buy and design the appropriate valves.

1. Medical Solenoid Valve Normally Closed

The valve of this type is closed when the coil is not energized. When the electrical power is supplied, the magnetic field moves the plunger and opens the path for the flow.

The NC valve is very useful when the system is expected to prevent the flow unless an electrical control signal is applied. This type of valve can be used in cases when the default condition of the equipment also requires that the flow should be stopped.

Common concept:

Power OFF → Open

Power ON → Closed

The exact behavior of the safety valve should always be analyzed as a part of the equipment design.

2. Medical Solenoid Valve Normally Open

The valve of this type passes the flow with the coil being de-energized. The internal mechanism slides to close the flow path when the power is applied.

Such an arrangement can be very beneficial when the default condition of the equipment is an open flow path.

Normal concept:

Power OFF → Open

Power ON → Closed

The choice of NC or NO valve depends on the operation sequence and fail-state behavior of the equipment.

3. Medical Solenoid Valve (2-Way)

The 2-way valves usually have two ports and control one flow path.

The main purpose of this type of valve is to:

Open → Flow

Closed → No flow

2-way valves are often used for simple ON/OFF control applications when the equipment needs to start or stop the flow path.

Selection criteria are orifice size, flow rate, pressure differential, leakage, response time, and coil power.

4. Medical Solenoid Valve (3-Way)

The 3-way solenoid valve has three ports and can control or redirect flow through different paths.

It can, depending on the internal valve configuration:

Connect the inlet to the outlet.

Connect the exhaust to the outlet.

toggle between two flow paths,

disjoint one flow path from another

Thus, 3-way design valves can be useful in systems with complicated pneumatic and fluidic control.

5. Directly operated medical solenoid valves

In direct-acting valves, the electromagnetic force directly moves the plunger or sealing element.

The advantage of such valves is that they can operate without a pilot pressure differential. This makes direct-acting valves attractive for low-pressure applications and some compact systems.

However, the delicate balance of flow capacity, orifice size, coil force, and power consumption should be maintained.

6. Solenoid Valve, Pilot Operated

In pilot-operated valves, the system pressure and pilot pressure work together to open and close the main valve.

This architecture provides high flow capacity and controls the valve with a relatively compact electromagnetic actuator.

However, pilot-operated valves have more specific pressure requirements and cannot be applied for all low-pressure applications.

7. Small Medical Solenoid Valve

Miniature valves are used in equipment with limited installation space.

They can be useful for:

portable medical devices,

detection tools,

laboratory analyzers,

compact fluid control systems,

battery-operated equipment

OEM engineers should not limit their selection of miniature valves to physical size alone. They should also consider the flow, pressure, coil temperature, leakage, lifetime, and connectors.

8. Medical Solenoid Valve for Low Power

Designing for low power saves energy consumption and heat generation. This is especially important for portable equipment or those with limited thermal management capabilities.

But low electrical power should still provide enough magnetic force to reliably operate the valve.

Therefore, the designer should consider the relationship between the following factors:

Voltage → Current → Coil Power → Magnetic Force → Response → Temperature

9. Customized Medical Solenoid Valve

All OEMs will not need the mechanical and performance parameters of a catalog valve. Customized valves can be designed for specific dimensions, flow rates, pressures, voltages, connectors, materials, sealing systems, and installation requirements.

For customized projects, the buyer should provide as much information as possible, including:

Control – medium,

service pressure,

flow required,

voltage,

the duty cycle,

installation size,

port setup,

leakage specifications,

operating temperature,

required lifetime

The OEM development process usually includes the stages of specification, design, prototype, sample testing, validation, and mass production.

10. Medical Solenoid Valve Types Comparison

Valve Type	Main Characteristic	Typical Selection Reason
Normally Closed	Closed without power	Default no-flow condition
Normally Open	Open without power	Default flow condition
2-Way	Two-port ON/OFF control	Simple fluid or gas switching
3-Way	Three-port flow routing	More complex flow control
Direct Acting	The plunger directly actuates the valve.	Compact / low-pressure applications
Pilot Operated	Pressure assists operation.	Higher flow applications
Miniature	Compact construction	Space-limited equipment
Low Power	Reduced coil consumption	Portable / thermal-sensitive equipment
Custom OEM	Application-specific design	Non-standard requirements

The best type of medical solenoid valve depends on the whole system, not on one parameter. The controlled medium, flow rate, pressure, electrical requirements, response time, leakage, temperature, installation size, lifetime, and quality requirements should be considered by the OEM engineers simultaneously.

Suppliers’ capabilities are also critical for medical equipment. A competent supplier should be able to design, prototype, test, and control quality and production consistency rather than provide standard valves.

Custom Medical Solenoid Valve Industrial Application

Medical solenoid valves are used in much equipment where automated control of the gas or liquid is required. They can control the paths of the air or gas in respiratory equipment, switching it depending on programmed operation conditions. Depending on equipment design and requirements, compact valves can be used in oxygen service for controlling the gas flow.

Solenoid valves can control air, liquid reagents, or other process fluids in diagnostic equipment. Laboratory analyzers often include several valves for directing fluids into pumps, chambers, and measurement components. Operation of the solenoid valves is electrically controlled, and it allows the equipment controller to automate processes.

Medical solenoid valves can also be used in fluid handling equipment, especially for precise flow path switching applications. In portable medical equipment where installation space and battery capacity are limited, compact design and low power consumption of the valve become crucial.

Other applications may include anesthesia equipment, sterilization systems, dental equipment, medical pumps, laboratory instruments, patient care systems, and automated testing equipment.

Each application should be analyzed with regard to medium, pressure, flow rate, temperature, duty cycle, leakage rate, material compatibility, and regulations for medical equipment.

Medical Solenoid Valve Technology: What Makes it Relevant for Automotive Systems?

It is important to distinguish between medical and automotive solenoid valves. It is not a wise decision to assume automatically that the valve designed for medical equipment is good for an automotive application. Automotive systems have their own requirements for temperature, vibration, contamination, environmental durability, electrical transients, materials, and industry norms.

However, the basic compact electromagnetic valve technology is also very valuable for automotive systems solutions. Contemporary vehicles increasingly rely on electronically controlled systems, which require precise switching of air, gas, coolant, fuel-related fluids, or other media. Compact solenoid valves can help to automate the control process and simplify the mechanical part of the vehicle.

The advantages of electromagnetic valves are fast electrical actuation, compact construction, repeatability of switching, flexibility of control, and possibility of connection to an electronic control unit.

Simply transferring a medical design to the automotive world is not the right approach. The designer should select the valve that was designed and tested for automotive conditions. The key parameters include operating temperature, vibration, pressure, electrical transients, sealing durability, corrosion resistance, contamination, lifetime, and industry standards.

So the better message is that solenoid valve technology is becoming increasingly important for medical and automotive automation, but the final valve design should be application-specific.

Custom Medical Solenoid Valve Advantage and Disadvantage

Custom Medical Solenoid Valve Advantage

Medical solenoid valves have many advantages in comparison with other valves for automated medical equipment. With electromagnetic electronic controllers it is possible to open and close liquid or gas flow paths rapidly and repeatedly without human involvement. The compact design enables to save installation space which is especially important for portable or space-limited equipment. They can also provide consistent switching performance and can be customized for voltage, port configuration, dimensions, flow rate, pressure and mounting. Reliable automation and repeatable equipment performance can be ensured with proper valves selection.

Custom Medical Solenoid Valve Disadvantage

However, there are also disadvantages of solenoid valves. Heat is generated when the coil is energized which can be important in case of continuous operation. Power consumption may also be an important parameter for battery-operated equipment. The flow capacity of a valve depends on the internal construction and orifice size, therefore compact valve may not provide high flow rate. Long operating periods may lead to wear of mechanical components like plungers, springs and seals. Poor material selection causes material compatibility and leakage problems. Besides, in some applications the valves generate switching noise or vibration.

Therefore, buyers should evaluate the entire system, not just one parameter. The valve is a compromise of size, flow rate, pressure, power consumption, reaction time, leakage rate, life time, cost and integration needs.

Medical Solenoid Valve Troubleshooting Guide

Trouble 1: Valve is Not Working Properly

Check power supply, wiring, connector, coil resistance, and output of the controller. Make sure the coil receives the actual voltage.

Trouble 2: Valve is Working, but the Flow is Too Low

Check the inlet pressure, outlet pressure, orifice size, tubing size, filters, and flow direction. In other places of the system, restrictions can reduce flow.

Trouble 3: Valve Does Not Close Properly

Check the contamination, damaged seals, incorrect assembly, and insufficient magnetic force or pressure conditions.

Trouble 4: Leakage Excessively High

Check the sealing surface, O-rings, valve seats, and connections in the body and assembly conditions. The sealing material must be compatible with the controlled medium.

Trouble 5: Coil Overheating

Check the voltage, current, duty cycle, switching frequency, ambient temperature, and installation conditions. Overvoltage or out-of-design operating can cause overheating.

Trouble 6: Reaction is Slow

Check electrical signal, supply voltage, pressure differential, mechanical friction, contamination, and spring characteristics.

Trouble 7: Too much Noise

Check mounting, vibration, plunger movement, electrical drive characteristics, and mechanical contact surfaces.

Trouble 8: Too Short a Life Time

Operating pressure, temperature, switching frequency, contamination, material compatibility, duty cycle, and installation conditions. If the trouble exists, perform a life test under the actual system conditions.

6 FAQs about Medical Solenoid Valve

1.What materials are used in their construction?

Manufacturers use highly biocompatible, corrosion-resistant materials to guarantee patient safety and chemical compatibility. Stainless steel (e.g. grade 316L), PEEK, PTFE, and medical-grade elastomers such as FKM or EPDM for seals are the most common.

2.How do medical solenoid valves prevent contamination of fluids?

Medical devices usually operate with microfluidic volumes or at very low pressures. Direct-acting valves are not dependent on system pressure differentials to open or close. This allows precise and instantaneous control of the fluid and gas from zero pressure up.

4.What is the electrical specification?

These valves are usually operated with low-voltage DC power (commonly 12V or 24V DC) to reduce the heat generated and prolong battery life in portable equipment. Many modern designs use PWM (pulse width modulation) to cut the power consumption after actuation.

5. What is done to prepare the valves for oxygen service?

Valves for use in high-concentration oxygen applications are degreased and specially cleaned to remove any microscopic traces of oil, grease, or hydrocarbons. These traces can create catastrophic combustion hazard in oxygen-rich environments.

6.What is life expectancy and maintenance?

High-reliability medical solenoid valves are designed for long life and are rated for 50-100 million cycles. Medical equipment requires extreme uptime, so these components are always designed for sealed and maintenance-free operation.

How to Choose a Medical Solenoid Valve For your project needs

Valve selection for medical equipment is not only matching the physical dimensions of the valve. The valve should be appropriate to the total environment of usage of the equipment.

1. Medium Identification

First, it is necessary to identify whether the valve is going to control air, oxygen, water, vacuum, gas, liquid reagents, or any other fluid. Medium determines much of the material and sealing compatibility.

2. Definition of Flow Requirements

It is necessary to calculate the effective flow rate of the valve. Consider the desired flow, pressure difference, orifice size, and whether the flow should be constant or variable.

3. Pressure Checking

It is necessary to set minimum, normal, and maximum pressure values. The valve should operate correctly within the whole range of pressures, not only nominal working pressure.

4. Valve Configuration

It is necessary to determine if a 2-way or 3-way valve and a normally open or normally closed valve are required. Proper configuration depends on the safety and control logic of the equipment.

5. Electrical requirements verification

Specify the available voltage, e.g., 12V DC, 24V DC, etc.; current; coil resistance; power consumption; and duty cycle.

6. Analysis of Response Time

In fast switching systems, response time may be crucial for the performance of equipment. Compare opening and closing times of the valve.

7. Verification of the leakage rate

Leakage rate affects the pressure stability, measurement accuracy, gas consumption, and equipment performance. Specify leakage rate before selecting the valve.

8. Taking into account Installation Space

Medical devices are usually small and have limited dimensions. Consider valve dimensions, mounting dimensions, port locations, connector location, and maintenance access.

9. Thermal Performance Analysis

Coil temperatures may increase during continuous or high-frequency operation. Verify the thermal performance of the valve under a real duty cycle.

10. Evaluation of Service Life

Define the number of operating cycles to be required and test the valve under realistic conditions. The valve that passed the short functional test may not meet long-term reliability requirements.

11. Customization capability assessment

In the case of OEM projects, the supplier should be able to change dimensions, coils, materials, connectors, ports, mounting dimensions, and performance parameters if necessary.

12. Final design review

Test the samples of valves on the equipment before large-scale production. Test flow, pressure, leakage rate, response time, temperature, electrical performance, noise, and service life under realistic operating conditions.

Therefore, the best medical solenoid valve is not necessarily the smallest and the cheapest. The valve provides the required performance and is designed to meet the mechanical, electrical, fluidic, reliability, and quality requirements of the equipment.

Common Mistakes in Design of the Medical Solenoid Valve and How to Avoid Them

1. Do not choose a valve based on size alone

The valve may be appropriate for the equipment in terms of size but does not provide sufficient flow or pressure performance.

2. Do not overlook real medium

Different fluids, such as gas, water, chemicals, etc., have different material compatibility requirements. Always check the valve body and sealing material.

3. Specify pressure conditions clearly

Do not give just pressure value. Provide minimum, normal, and maximum pressure values.

4. Consider the whole duty cycle

A coil that works properly for several seconds can overheat and fail when operated continuously. Test the valve under a realistic duty cycle.

5. Leave enough room for installation

Consider not only the valve body but also connectors, wires, mounting hardware, tubing, maintenance access, and manufacturing tolerances.

6. Specify the leakage rate

Leakage rate is a design parameter and should be considered during the design stage, not when the prototypes are built.

7. Verify the coil compatibility with the control system

Check voltage, current, power consumption, resistance, switching frequency, and controller compatibility.

8. Do not change materials without validation

Plunger, valve body, spring, and sealing materials may change magnetic force, corrosion resistance, leakage rate, lifetime, and material compatibility.

9. Test the whole system

Bench testing may not reveal problems with pumps, tubing, pressure fluctuations, controllers, and installation orientation.

10. Define quality requirements before large-scale production

Before production it is necessary to agree on critical dimensions, electrical testing, leakage limits, performance tests, inspection methods, and sampling.