How an Excavator Main Relief Valve Works: Structure & Function

How an Excavator Main Relief Valve Works: Structure & Function Explained
"Ever wondered what protects your excavator's hydraulic system from overpressure? Meet the main relief valve​ – the system's pressure safety guardian! ⚙️🛡️
The Main Components:
🔹 Main Valve Body​ – The housing that contains everything
🔹 Main Spool​ – The primary moving part that controls flow
🔹 Spring​ – Provides the closing force
🔹 Spring Seat​ – Supports and positions the spring
🔹 Poppet Valve​ – The precision cone-shaped valve that opens first
🔹 Adjustment Screw​ – Lets mechanics set the pressure limit
How It Works - Step by Step:
Step 1: Normal Operation​
✅ Hydraulic oil pressure is below the set limit
✅ The spring force​ keeps the poppet valve closed​
✅ All oil flows normally to cylinders and motors
Step 2: Pressure Builds​
🔼 As hydraulic pressure increases from the pump...
🔼 The force on the poppet valve​ increases...
🔼 Until it overcomes the spring force!
Step 3: Safety Release​
🚨 The poppet valve opens first​ (at the set pressure)
🚨 This allows oil to flow around the main spool​
🚨 The main spool then shifts, creating a large bypass path​
🚨 Excess oil returns safely to the tank​
🚨 Pressure drops back to safe levels
Step 4: Reset​
🔄 When pressure decreases below the set point...
🔄 The spring pushes everything back closed​
🔄 Normal operation resumes automatically!
Key Points:
🎯 Adjustment screw​ changes spring pre-load = changes pressure setting
🎯 Two-stage opening​ – poppet opens first, then main spool
🎯 Automatic operation​ – no electronics needed
🎯 Critical safety​ – prevents hose bursts and component damage
Pro Tip: Always check and adjust your relief valves during regular maintenance! 🔧
Need high-quality main relief valves​ for your excavator?"
🔧 Available at TONKEE:
✅ Main Relief Valves​ – Complete assemblies for all excavator models
✅ Relief Valve Repair Kits​ – Seals, springs, and poppet valves
✅ Adjustment Screw Kits​ – For precise pressure setting
✅ Pressure Test Kits​ – For accurate adjustment and testing
🏆 Why Choose TONKEE?​
Made in China​ – Precision-engineered with strict quality control
Pressure-Tested​ – Every valve tested before shipping
Large Stock​ – Ready for immediate delivery
1-Year Warranty​ – Confidence in every valve
📲 Contact TONKEE on WhatsApp:
+8613250597622​
(Send your excavator model for the right relief valve!)
"PRESSURE GUARDIAN · SYSTEM PROTECTOR · TONKEE VALVES"
https://www.pumpmotorfix.com/product-...
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