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Main advantages of coaxial valves

Apr 22,2025

The core advantages of a coaxial valve stem from its coaxial structural design (the valve stem and valve seat axes coincide), a feature that makes it stand out in terms of sealing performance, response speed, and reliability. The following are its main advantages and detailed analysis:

I. Excellent sealing performance, low leakage risk:

Coaxial alignment design:
- The valve stem and valve seat are concentrically matched, the sealing surface is evenly stressed, and it can form line sealing or surface sealing ，with high sealing accuracy (the leakage rate of some models can reach zero leakage level).
- Suitable for high pressure, high vacuum, flammable and explosive, or high-purity media (such as refrigerants, fuel gas, and pharmaceutical liquids), avoiding safety hazards or media waste caused by leakage.
- Case ：In refrigeration systems, coaxial solenoid valves can achieve zero-leakage switching of refrigerants, improving energy efficiency and reducing the loss of environmentally friendly refrigerants (such as R32).
Various sealing structures are optional:
- Metal hard seal ：Suitable for high temperature, high pressure, and media containing particles (such as steam and slurry), wear-resistant and erosion-resistant.
- Soft seal (such as fluororubber and polytetrafluoroethylene): Stronger sealing, suitable for low-viscosity liquids or gases (such as water and air), and can reduce opening and closing noise.

II. Fast response speed, suitable for high-frequency operation:

Low flow resistance and agile control:
- Short valve stem stroke (some solenoid valves only need a few millimeters of displacement to complete opening and closing), and smooth fluid passage (the flow path is straight or short), with low pressure loss.
- The response time of electromagnetically driven coaxial valves can reach millisecond level (such as 10-50ms), suitable for scenarios requiring quick start/stop or high-frequency switching (such as automated production lines and medical equipment).
- Scenario ：In hemodialysis machines, the coaxial valve needs to complete several fluid switches per second to ensure accurate dialysis solution mixing, and the response speed directly affects the safety of treatment.
Strong resistance to fluid impact:
- The coaxial structure makes the valve stem force balanced, and it is not easy to vibrate or jam due to fluid impact during opening and closing, especially suitable for high-pressure pulse conditions (such as hydraulic systems and gas peak regulation stations).

III. Compact structure, saving space and installation costs:

Small size and light weight
- Compared with traditional valves (such as ball valves and gate valves), coaxial valves do not require complex transmission mechanisms (such as worm gears), the structure is more compact, and the installation space can be reduced by 30%-50%.
- Application ：In aerospace equipment (such as aircraft hydraulic pipelines), the lightweight design of coaxial valves can reduce the overall weight and improve fuel efficiency.
Integrated design advantages
- It can be integrated with sensors and actuators (such as built-in position feedback devices and pressure transmitters) to achieve integrated "valve + control system", simplifying pipeline layout.
- Case ：In the automatic control system of chemical reaction kettles, coaxial valves integrated with pressure sensors can automatically open and close according to the pressure inside the kettle in real time, reducing external pipeline connection points and lowering the risk of leakage.

IV. Wide range of applications, strong working condition compatibility:

Wide temperature and pressure working capacity:
- Wide operating temperature range (-196℃~+450℃): Low-temperature scenarios (such as LNG transportation) can use cryogenic coaxial valves (materials are stainless steel + cryogenic seals); high-temperature scenarios (such as steam pipelines) can choose metal hard seals + high-temperature coating valve stems.
- Pressure range covers vacuum (-0.1MPa) to ultra-high pressure (above 100MPa) ：For example, in the ultra-high-pressure water injection system of oil exploration, coaxial stop valves can withstand 150MPa high pressure to ensure the safety of downhole operations.
Strong media adaptability:
- Can control liquids, gases, slurries, and corrosive media ：
  - Corrosive scenarios (such as sulfuric acid and sodium hydroxide): Use stainless steel + fluoroplastic lining or titanium alloy materials.
  - Media containing particles (such as slurry and sewage): Select wear-resistant metal seals + self-cleaning valve stem structure to reduce impurity jamming.

V. Easy maintenance, long service life:

Modular structural design:
- Easily damaged parts such as valve stems and seals can be disassembled and replaced separately without disassembling the entire valve or interrupting the entire pipeline system, resulting in low maintenance costs and short time consumption.
- Data ：The average failure-free operation times of a certain brand of coaxial solenoid valves can reach more than 1 million times, and the service life under normal working conditions can reach 5-10 years.
Anti-pollution and self-cleaning ability:
- The coaxial valve flow path is smooth, and the direction of media flow is consistent with the axis of the valve stem, which can reduce media retention and deposition; some models are designed with a "flushing" flow path, which can automatically clean impurities on the sealing surface through media flow.
- Scenario In food and beverage production lines, self-cleaning coaxial valves prevent bacterial growth caused by juice residue buildup, meeting Clean-In-Place (CIP) requirements.

VI. Flexible Control Methods, Adapting to Diverse Needs:

Multiple drive options available:
- Electromagnetic drive Suitable for automated scenarios (such as PLC control), fast response but lower power (commonly used for pipes with a diameter of DN50 or less).
- Pneumatic/Hydraulic drive Can provide greater driving force, suitable for large-diameter (such as DN200 or above) or high-pressure valves, and supports remote control.
- Manual/Electric drive As a backup or local control method, ensuring system operation during power outages or air source failures.
Precise Adjustment Capability (Some Models):
- In addition to the switching function, some coaxial valves (such as proportional solenoid valves and electric regulating valves) can achieve continuous flow regulation through control signals (such as 4-20mA current), with accuracy up to ±1%, suitable for scenarios requiring precise metering (such as drug solution proportioning in the pharmaceutical industry).

Summary: Core Advantage Comparison:

Advantage Dimension	Coaxial Valve Features	Comparison with Traditional Valves (such as ball valves and butterfly valves)
Sealing Performance	Coaxial sealing, low leakage rate (can achieve zero leakage)	Ball valves require tight contact between the ball and the valve seat, and are prone to wear and leakage under high pressure.
Response Speed	Millisecond level (electromagnetic drive)	Butterfly valves and gate valves have slower response times (second level) due to the inertia of the transmission mechanism.
Compact Structure	Small size, reduces installation space by 30%-50%	Ball valves and gate valves require space for operation (such as handles and drive devices).
Medium Adaptability	High pressure, low temperature, corrosion resistant, supports media containing particles.	Soft-sealed ball/butterfly valves are easily worn by particles, and hard-sealed valves are expensive.
Maintenance Convenience	Modular design, easily replaceable wear parts.	Overall disassembly and maintenance, time-consuming.

Application Suggestions If the working conditions require high sealing, fast response, compact installation, or complex media control coaxial valves are the preferred option; if only low-cost, large-diameter control is needed (such as water supply and drainage pipes), traditional valves may be more economical.