803004055 check valves for XCMG ZL50G/ZL50GL Wheel Loader

product parameters

Part Number：803004055
Product Name：Check Valve
Applicable Model：XCMG ZL50G, ZL50GL Wheel Loader
Body Material：Alloy steel / Ductile iron
Spool & Seat：Heat-treated alloy steel
Cracking Pressure：OEM standard opening pressure
Rated Working Pressure：System rated pressure
Working Medium：L-HM46 anti-wear hydraulic oil
Working Temperature：-20℃ ~ 80℃
Connection Form：Threaded connection / cartridge type
Inspection Items：Sealing test, opening pressure test, internal leakage test, appearance and dimensional inspection

Applicable Scenarios

It is widely used in the load-holding oil circuit of lifting cylinder, bucket cylinder and auxiliary hydraulic circuit of 5-ton wheel loader, suitable for earthwork, quarry, sand yard, port bulk cargo loading and other heavy-duty construction scenarios.

• Manufactured according to OEM specifications, consistent thread and installation size with original parts, direct replacement without modification.
• Precision grinding matching between spool and valve seat, extremely low internal leakage, reliable load holding effect to avoid bucket creeping down.
• Heat-treated moving parts, high surface hardness, anti-wear and anti-scuffing, long service life under repeated opening and closing cycles.
• Stable spring performance, consistent opening pressure, sensitive response and stable cut-off action.
• Compact structure, small installation space occupation, convenient for layout inside valve block or pipeline.
• Good impact resistance, can adapt to frequent pressure fluctuation and mechanical vibration of construction machinery.

FAQ 

Q1: What will happen if the check valve is installed reversely?
A1: Reverse installation will completely block forward oil flow, the actuator cannot move normally, the boom or bucket cannot lift or turn. Install strictly following the oil flow marking arrow.

Q2: What causes the check valve to leak internally and the bucket sinks slowly?
A2: It is usually caused by hard particles stuck between spool and seat, valve seat scratch, spring fatigue failure, or oil pollution.

Q3: Can this check valve be used for other brand loaders at will?
A3: Not recommended. The cracking pressure, interface thread and installation cavity are customized for ZL50G/ZL50GL, mismatched parameters will cause abnormal hydraulic action.

Q4: How to judge whether the 单向阀 is damaged?
A4: Check whether the load sinks without operation, whether the oil circuit cannot build pressure, or abnormal noise occurs when oil flows through. Replace it after confirming the fault.

Q5: What maintenance requirements for hydraulic oil to extend the valve service life?
A5: Keep hydraulic oil clean, replace oil and filter regularly, control oil pollution grade, reduce particle abrasion to the sealing surface.