HD – SV/SL – Hydraulically Pilot Operated Check Valve
Ensure absolute safety and precise directional control in your high-pressure circuits with the HD SV/SL Series Hydraulically Pilot Operated Check Valves. Available through THM Hydraulics, this critical component acts as an impenetrable lock for your hydraulic cylinders, securely holding heavy loads in place. Unlike standard check valves, the SV/SL series utilizes a fluid-controlled pilot mechanism, allowing you to intentionally override the check function and permit controlled reverse flow when required. Engineered to handle extreme pressures up to 315 bar and massive flow rates up to 550 L/min, this valve delivers the rugged reliability required to protect your machinery and personnel in the most demanding industrial environments.
Core Technical Specifications:-
- Component Architecture: Hydraulically Pilot Operated Check Valve
- Model Variations: HD-SV (Single Pilot) and HD-SL (Double Pilot)
- Maximum Operating Pressure: Up to 315 bar
- Maximum Flow Capacity: Up to 550 L/min
- Opening Pressures: 4 distinct opening pressure options available
- Standardization: Porting pattern to DIN 24 340 Form A, ISO 4401, and CETOP-RP 121H
- Mounting Styles: Subplate mounting or Threaded (inline) connection
Key Features & Engineering Advantages:-
- On-Demand Reverse Flow: Under normal operation, fluid flows freely in one direction and is completely blocked in reverse. By applying hydraulic pilot pressure to the designated port, an internal piston mechanically forces the poppet open, enabling smooth, controlled reverse flow to retract cylinders or reverse motors.
- Fail-Safe Load Holding: The moment pilot pressure is removed, the valve instantly snaps shut. This prevents vertical or suspended loads from dropping erratically due to sudden power loss, hose bursts, or internal system leaks.
- Dampened Decompression (Pre-Opening): Available with an optional pre-opening feature. This allows high-pressure fluid to bleed off gradually before the main poppet fully opens, eliminating violent hydraulic shock and extending the life of your cylinders and seals.
- SV vs. SL Configurations: Choose the SV (Single Pilot) for controlling flow in one direction (ideal for single-acting cylinders), or the SL (Double Pilot) for synchronized load holding in both directions on double-acting cylinders.
- Customizable Leakage & Piloting: Configure your valve with internal or external pilot lines based on your manifold layout, and choose variants with or without a controlled leakage path for applications requiring slow, precise pressure bleeding.
Ideal Industry Applications:-
The fail-safe load holding and high-flow pilot control make the HD SV/SL series mandatory for:
- Heavy Lifting & Material Handling: Securing the position of hydraulic cylinders on forklifts, stackers, and heavy-duty cranes until the operator initiates a lowering sequence.
- Industrial Forging & Presses: Holding massive press platens securely in the raised position during idle times or maintenance, preventing unexpected drops.
- Injection Molding Machinery: Maintaining uniform mold-locking pressure throughout the entire high-speed injection cycle.
- Mobile & Construction Equipment: Safely locking the boom and arm positions on excavators and loaders, ensuring stability on uneven terrain.
- Wind & Renewable Energy: Serving as the ultra-reliable fluid lock for pitch control and emergency braking systems on wind turbines.
Why Choose the HD SV/SL Series?
- Zero-Drop Reliability: Protect your equipment and your workforce. When the SV/SL valve closes, the load stays exactly where you put it, period.
- Eliminate Hydraulic Shock: The optional pre-opening feature ensures that releasing massive trapped pressure is a smooth, quiet event, preventing destructive "hammering" in your steel lines.
- Ultimate System Flexibility: With threaded, subplate, and cartridge options, alongside single or double pilot designs, this valve series can be perfectly tailored to any existing hydraulic schematic.
