Control Valve

SOLH 4H series hand lever directional control valves are developed in accordance with mainstream industrial standards, covering 5/2-position and 5/3-position configurations. Operated purely by manual lever manipulation without electromagnetic coils or pneumatic pilot signals, these spool-type manual valves are widely adopted for on-site equipment commissioning, emergency safety shutdown and inching control of double-acting cylinders. Constructed with high-strength aluminum alloy housings and precision spool assemblies, two positioning structures are optional: automatic spring return and steel ball mechanical locking. Crucially, the mounting dimensions are fully consistent with 4V solenoid valves and 4A air-operated valves, enabling direct interchange and flexible switching among electric, pneumatic and manual control modes in standard pneumatic systems. The five-port layout complies with international general specifications: P serves as the main compressed air supply inlet; Ports A and B connect to two cavities of double-acting cylinders to govern extension and retraction movements; R and S are exhaust ports compatible with standard silencers to lower exhaust noise. For 5/2-position models, spring-reset variants automatically rebound once the lever is released to deliver foolproof protection against unintended continuous actions; self-locking versions secure the spool position via steel ball positioning and stay latched until manual switching, ideal for long-duration fixed working states. All 5/3-position units adopt dual stable ball positioning with three configurable neutral modes. Closed Center (Type C) seals all ports to lock cylinders and prevent falling of vertically mounted actuators; Exhaust Center (Type C) vents A/B ports for pressure relief, allowing free cylinder floating during manual testing; Pressure Center (Type P) supplies compressed air to both working ports for synchronous clamping and force balance regulation. Running on filtered compressed air within 0.15~0.8 MPa under lubrication-free conditions, the valves work steadily at -20℃ to +70℃. Available specifications range from 4H200 to 4H400 with multiple thread options. Devoid of electrical components, the valves feature spark-free inherent explosion resistance, well-suited for flammable, dusty and high-risk production sites. They support panel mounting and base installation, frequently applied for production line manual commissioning, emergency pneumatic circuit cut-off, safety interlock loops and retrofitting replacement of automatic control valves.

SOLH 3L series 3/2-way hand pull directional control valves follow standard industry specifications with a default Normally Closed (NC) structure equipped with automatic spring return. Operated via straightforward axial push-pull handle movement, this manual pneumatic valve requires no electric parts or pneumatic drive signals, making it an intrinsically safe manual switching component for pneumatic circuits. It is widely deployed for single-acting cylinder actuation, circuit on-off switching, inching commissioning and safety interlock systems, especially ideal for field debugging, emergency cut-off and explosion-prone working environments. The three-port layout complies with universal industry standards: P for main compressed air inlet, A for working output port connecting single-acting cylinders, and R for exhaust port compatible with standard silencers to reduce exhaust noise. Under normal released status, the built-in return spring presses the precision spool to seal the P inlet; port A links to R for pressure relief to maintain the closed safe state. Manual pulling of the handle shifts the spool to connect P and A ports for air supply to drive cylinder movement. Once released, the spring instantly resets the valve, cutting air intake and exhausting residual pressure to prevent unintended continuous operation. Constructed with robust aluminum alloy housings and low-friction precision spools, the valve supports lubrication-free operation with stable sealing performance. Four size grades ranging from compact 3L100 up to heavy-duty 3L400 cover thread specifications M5, G1/8, G1/4, G3/8 and G1/2; PT, NPT and G thread options are available to satisfy global installation demands. The valve supports panel mounting and base mounting, sharing identical installation dimensions with the 3A air-operated valves for seamless interchange between manual and pneumatic control modes. Without any electrical components, it delivers spark-free operation suitable for flammable, dusty and humid workshops, commonly used for manual clamping, ejection cylinder control, equipment maintenance safety lockout and combined manual-pneumatic logic control systems paired with 3A pilot valves.

SOLH 4A series 5/2-way and 5/3-way air-operated directional control valves are the full pneumatic counterpart of the classic 4V electromagnetic solenoid valve series. Driven entirely by external pneumatic control signals with no coils or electrical parts inside, this valve achieves inherent explosion-proof safety and serves as the core control unit for non-electric pneumatic loops, hazardous explosive areas and safety interlock systems. It adopts high-precision spool configuration and robust aluminum alloy housings, sharing identical installation dimensions and flow characteristics with the 4V series for seamless direct replacement and upgrade between electric-driven and full-pneumatic control schemes. The standard five-port layout follows industry universal specifications: P for main air supply inlet, A and B as working ports connected to two chambers of double-acting cylinders for extension and retraction regulation, R and S as exhaust ports compatible with standard silencers to reduce operational noise. The 5/2-way lineup supplies single pneumatic control and double pneumatic control options. Single air-controlled models switch upon receiving control air signals and automatically reset by built-in springs once the control pressure disappears to deliver fail-safe protection. Double air-controlled variants feature no return springs and lock the current spool position persistently after control air is disconnected, supporting long-duration positioning and pressure retention without sustained control air input. 5/3-way versions are exclusively double air-driven with three selectable neutral configurations: closed center (Type C) seals all ports to lock cylinders and prevent vertical falling; exhaust center (Type E) vents A/B ports to atmosphere for pressure release and manual commissioning; pressure center (Type P) feeds compressed air to both working ports for synchronous clamping and force balance adjustment. Suitable for filtered compressed air within 0.15~0.8 MPa working pressure, the whole series supports lubrication-free operation and works reliably from -20℃ to +70℃. Widely applied in chemical plants, painting workshops, mining and other explosion-risk environments, it cooperates with mechanical valves, hand-operated valves and air pilot valves to build complete all-pneumatic logic control systems for double-acting cylinders.

SOLH 3A series 3/2-way externally air-operated directional control valves are manufactured in accordance with mainstream industry standards. Driven entirely by pneumatic signal input without any electromagnetic coils, this series is engineered to govern extension, retraction and pressure retention of single-acting pneumatic cylinders. It serves as the critical safety control element for all-electric-free pneumatic circuits, hazardous explosive atmospheres and fail-safe industrial machinery. The standard three-port layout follows universal industrial definitions: P for main compressed air supply inlet, A for working outlet connected directly to single-acting cylinders, and R for exhaust port for pressure relief and rapid spring reset. Two control configurations are available. Single pneumatic control models (3A×10) switch upon receiving external air signals and automatically reset via built-in springs once the control air signal is removed to guarantee fail-safe reset performance. Double pneumatic control variants (3A×20) adopt latching spool structure, locking the valve position persistently even after control air is disconnected to sustain long-term clamping and positioning. Constructed with high-strength aluminum alloy valve bodies and precision-machined spools, the valves support oil-free operation under filtered compressed air with filtration precision above 40 μm within the working pressure range of 0.15~0.8 MPa. Four dimensional specifications from miniature 3A100 up to heavy-duty high-flow 3A400 cover M5 to G1/2 thread connections, and NPT threads are optional for overseas projects. Without internal electrical parts, the valve features intrinsic explosion-proof performance, perfectly suited for flammable, dusty and humid working environments. It supports random multi-angle installation and manifold assembly for modular valve banks, widely deployed in workpiece clamping mechanisms, pneumatic safety interlock systems and long-duration positioning stations.