Heavy-Duty Safety Lock Screw-to-Connect Hydraulic Quick Couplings

Product Specification

Feature

JINGYE Fittings supplies JY-STC-HD Heavy-Duty Safety Lock Screw-to-Connect Hydraulic Quick Couplings for heavy-duty hydraulics. Flat-face double shutoff, threaded mechanical engagement and a secondary anti-loosening feature support secure, low-spill connections. Key Product Advantages: 1. JY-STC-HD Series and Coupling Selection JY-STC-HD is the published heavy-duty safety-lock family. JINGYE coupling-set descriptions cover 3/8"–2" BSP/NPT end-port options, with selected configurations described up to 550 bar. Select body size, port thread, male plug, female socket and safety-lock arrangement separately. Port size and mating threads differ. 2. Secondary Safety Lock and Anti-Loosening Design A supplementary mechanical feature helps resist unintended unscrewing after the threaded halves are engaged. Depending on the design, this may be a locking pin, safety sleeve, detent or anti-rotation element. Comparable designs use a locking pin or integrated safety sleeve. The selected configuration determines the mechanism. 3. Screw-to-Connect Threaded Retention A rotating sleeve or coupling nut draws the male and female halves together through matching threads. Thread engagement length, axial travel, concentricity, torque and sleeve movement influence connection reliability. Mechanical screw locking is distinct from push-to-connect ball locking; mating threads are also separate from BSPP, NPT or SAE hydraulic ports. 4. Flat-Face Valves and Double Shutoff Spring-loaded flat-face shutoff valves close both disconnected halves and open during full coupling engagement. Flush mating surfaces allow dirt to be wiped away before connection, helping reduce oil spillage and air inclusion. Precision valve seats, O-rings and spring return support sealing. Low-spillage construction is not a zero-leakage guarantee. 5. Heavy-Duty Pressure and Structural Strength Selected JY-STC-HD coupling-set descriptions reference working pressures up to 550 bar. Comparable Stucchi VEP-HD designs reach 550 bar, while the separate VP-P safety-lock series reaches up to 600 bar. Such figures belong to different configurations and are not interchangeable product ratings. Confirm size-specific working pressure, proof/burst strength and coupled/uncoupled limits. 6. Hydraulic Flow, Pressure Drop and Oil Spillage Comparable Stucchi VEP-HD series data report maximum flow up to 750 L/min in selected sizes. Separate Kuaishi RK/RK-KL references list 420 bar working pressure and rated flows of 23–288 L/min, with reported disconnection spillage of 0.02–1.00 mL. These are reference values, not JY-STC-HD test results. Flow loss varies with oil viscosity, valve passages and coupling size. 7. Vibration Resistance and Pressure-Impulse Service Threaded engagement and an auxiliary lock suit equipment exposed to shock, vibration and pressure pulses. Performance depends on correct engagement and tightening. Relevant validation includes vibration exposure, retention checks, pressure impulse and repeated coupling cycles rather than a generic claim of vibration-proof operation. 8. Carbon Steel Construction, Seals and Coatings Precision CNC-machined carbon steel bodies and rotating sleeves may use hardened steel flat-face valves, wear parts, locking pins and corrosion-resistant springs. NBR and PU sealing systems suit compatible mineral oils, with FKM and PTFE backup options for selected conditions. Carbon-steel surface choices include trivalent chromium zinc plating, typically 8–12 μm, and optional Zn-Ni or QPQ protection. 9. Precision Inspection and Functional Verification JINGYE Fittings operates under ISO 9001:2015 quality management. Inspection controls mating profile, locking threads, sleeve travel, secondary-lock engagement, valve seats, sealing grooves, threaded ports and cleanliness. Agreed testing can include leakage, pressure drop, spillage, proof/burst pressure, impulse endurance, vibration security and repeated connection cycles. 10. OEM Configuration and Second-Source Supply Options include male plugs, female sockets and matching sets; selected pin-lock or sleeve-lock mechanisms; BSPP/NPT and engineered SAE/ORB ends; seal compounds, coatings, dust caps, marking and private-label packaging. Customer drawings and samples support mating comparison. JINGYE Fittings offers sample evaluation, mixed-SKU procurement, customized machining and repeat OEM supply. 11. Construction, Mining and Mobile Hydraulics Applications include excavator breakers, demolition attachments, drilling rigs, mining and quarrying machinery, forestry harvesters, cranes, loaders, heavy hydraulic power units, hose assemblies and industrial MRO. Safety-lock screw couplings suit detachable hydraulic circuits where secure mechanical retention, low-spillage shutoff and resistance to accidental loosening are priorities. CUP connection is a separately qualified feature.