measure spool for XCMG ZL50G/ZL50GL Wheel Loader

product parameters

Product Name: Metering Spool
Applicable Model: XCMG ZL50G, ZL50GL Wheel Loader
Matching Valve: D32 pilot multi-way valve
Matching Parts: Metering valve seat, adjusting spring, O-rings
Material: Alloy structural steel, quenched and precision ground
Sealing Type: Clearance throttling spool
Function: Flow metering and balanced flow distribution for compound operation
Nominal Port Size: 32mm
Medium: Anti-wear hydraulic oil for construction machinery
Working Temperature: -20℃ ~ +80℃
Inspection Items: Diameter check, concentricity test, metering notch profile inspection, pressure holding test, cycle durability test

Applicable Scenarios

Installed inside the metering valve seat of D32 multi-way valve, it balances flow for synchronized boom and bucket operation. Widely used in mines, sand yards, earthwork and cargo terminals.

• Machined strictly per original drawing, consistent dimension and metering notch profile for reliable interchangeability
• Quenched alloy steel with uniform surface hardness, excellent abrasion resistance against contaminants in hydraulic oil
• Pressure balance grooves eliminate hydraulic clamping, ensure smooth spool travel and consistent operation feel
• Optimized metering notches provide linear flow regulation, stable distribution under changing load and no flow competition
• Precisely controlled clearance balances smooth sliding and low internal leakage, maintain stable metering performance
• Cost-saving single-part repair solution; replace only the spool instead of whole valve section
• Individual flow and pressure inspection for stable batch quality, low risk of on-site failure
• Fully compatible with original metering seat, spring and seals, simple assembly and short downtime

FAQ 

Q：What symptoms occur when the metering spool is worn and scratched?
A：Unbalanced flow during compound operation, out-of-sync boom and bucket movement, speed fluctuation under load and frequent spool sticking.

Q：Does unsynchronized compound movement always mean the metering spool is damaged?
A：No. Check spring fatigue and O-ring leakage first. Exclude seat damage before confirming spool wear.

Q：Can a lightly scratched spool be polished for long-term use?
A：Polishing is only for emergency. Modified dimension changes flow characteristic and leads to recurring imbalance. New spool is recommended.

Q：Can metering spool interchange with sequence or overload spool?
A：Not interchangeable. Notch shape and flow curve differ. Wrong assembly causes disordered flow and operation risk.

Q：What should be noted during disassembly and assembly?
A：Clean the assembly thoroughly, protect seat passage, lubricate with clean oil, replace O-rings and test synchronization after installation.

Q：What causes metering spool scratching most often?
A：Contaminated hydraulic oil and clogged filters are the main causes. High temperature and repeated shock pressure also accelerate wear.

Q：Is calibration required after spool replacement?
A：Calibration is recommended. Test compound movement to verify balanced flow distribution.