How to Choose the Right Medical Solenoid Valve

Weilong Intelligent Technology Co., based in Guangdong Province, China (Zip code: 523128), has released a comprehensive guide on how to compare and choose the right medical solenoid valve. The company, which has been in business for almost 20 years and provides reliable solutions for various medical applications, aims to help engineers and manufacturers select the most suitable valve for their needs.

According to the guide, medical solenoid valves are crucial components in many medical devices, including ventilators, oxygen delivery systems, diagnostic analyzers, laboratory equipment, dialysis systems, anesthesia delivery systems, and suction devices. These valves control the flow, isolate the flow, measure the flow, or stop the flow of gases or fluids, ensuring precise and safe operations in medical settings.

The guide emphasizes that selecting the proper medical solenoid valve goes beyond basic parameters such as voltage and connection size. Key considerations include leakage, reaction time, power consumption, heating, material compatibility, cleanliness, noise, and life span. For compact portable medical devices, valve size and weight are also critical factors.

One of the first steps in specifying a valve is defining the medium that will be used. The guide lists several media that can be used, including air, oxygen, nitrogen, water, saline, reagents, cleaning fluids, and vacuum. Medium compatibility is crucial, as it affects almost every aspect of valve selection. The guide advises that detailed information on the composition, concentration, temperature, pressure, and duration of contact with the fluid should be provided to the manufacturer.

The guide also delves into the choice of valve configuration, noting that there are several flow configurations available. Two-way valves are commonly used for starting or stopping flow, while three-way valves provide the possibility of connecting a common port to two different flow paths. Multiport valves are used in more complex medical equipment to decrease the amount of tubing and facilitate assembly.

Another important parameter is the valve design, which can be either direct acting or pilot operated. Direct acting valves work without a minimum pressure differential and are suitable for low pressure systems, vacuum cleaners, small flow paths, and accurate pneumatic control in compact medical devices. Pilot operated valves require a minimum pressure differential but provide higher flow rates at relatively low coil power.

The guide stresses the importance of determining the required flow rate, which is one of the most critical specifications. Engineers should consider the flow rate in liters per minute (L/min) and standard L/min for gases. Pressure and vacuum requirements should also be specified, considering the minimum and maximum operating pressures, as well as pressure transients, pressure spikes, vacuum levels, back pressure, and pressure differential across the valve.

Leakage is another critical factor, with two general categories: external leakage and internal leakage. The guide advises that the term "zero leakage" cannot be used without a numerical test specification and defined test conditions. Material compatibility and seal materials are also important, with various options such as silicone, EPDM, FKM, PTFE, and other elastomers. The guide recommends that engineers check the suitability of the materials for the intended application.

Response time and repeatability are also crucial, with factors such as coil design, voltage, weight of the armature, spring power, strokes, fluid pressure, rubbing, and valve construction affecting the response time. The guide notes that quick response may be critical for respiratory devices, pneumatic controls, diagnostic equipment, dosing, and automated laboratory systems.

The correct voltage and power consumption are essential, with common DC supply voltages ranging from 3V DC to 24V DC. Engineers should consider the voltage, current, wattage, duty cycle, ambient temperature, and available heat dissipation simultaneously. Thermal and duty cycle characteristics are also important, with some valves designed for continuous operation and others for intermittent or pulse operation.

Noise and vibration are often overlooked but can be critical in patient-facing medical equipment. The guide advises that engineers should include noise as a specification during discussions with the manufacturer, not after testing prototypes.

Finally, the guide emphasizes the importance of checking the operating life of the valve, which can range from millions of switching cycles. Engineers should inquire about the definition of operating life and test the valve in conditions that simulate the application of the equipment.

Weilong Intelligent Technology Co. states that it defines itself as an engineering-oriented manufacturer with the capability of structural design, prototyping, tooling, testing, manufacturing, and custom development of solenoids and solenoid valves. The company's current portfolio includes other electromechanical products like pumps, proportional valves, and medical valves. It claims to be in accordance with ISO 9001 and IATF 16949, ensuring high-quality and special requirements for its products.

A batch of 5,000 solenoid pumps has recently landed at the company, and it is expected to reach $65.38 million by 2025 from $52.12 million in 2017, growing at a CAGR of 2.88% during the forecast period (2018-2025). Pressure safety valves are expected to register expansion at a 5.4% CAGR in terms of

The correct selection of medical solenoid valves is crucial for the safe and efficient operation of medical devices. Weilong's comprehensive guide provides valuable insights for engineers and manufacturers looking to choose the right valve for their applications.