MBDA-LHN Sun Hydraulics Pilot Check Valve 350 Bar

Product Overview

The MBDA-LHN (along with MBDALHN and MBDA series) is a screw-in cartridge pilot control check and pressure relief valve engineered for high-pressure load holding, overload protection, and motion control in hydraulic systems. Built to match standard Sun Hydraulics T-10A cavities, this cartridge serves as a 100% direct drop-in replacement without requiring manifold redesigns. Manufactured with precision-hardened alloy steel and floating construction, every valve undergoes 100% simulated factory condition testing to ensure zero internal leakage, minimal hysteresis, and instant dynamic response under continuous 350 bar operating conditions.

Technical Specifications 

• Model Codes: MBDA-LHN (Featured series includes MBDALHN, MBDA)

• Standard Cavity: Sun Cavity T-10A

• Nominal Flow Capacity: 60 L/min (15 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Peak Proof Pressure: 420 bar (6090 psi)

• Pressure Setting Range: Range H: 70 – 280 bar (1000 – 4000 psi)

• Internal Leakage Rate: ≤ 5 drops/min at 85% of set pressure

• Adjustment Mechanism: L-Control (Standard Hex Socket Screw Adjustment)

• Seal Material: Option N (Buna-N Nitrile standard, Viton/FKM optional)

• Fluid Temperature Range: -40°C to +100°C (-40°F to +212°F)

• Recommended Installation Torque: 45 – 50 Nm (35 – 40 lbf·ft)

• Unit Net Weight: Approx. 0.20 kg (0.44 lbs)

Key Technical Advantages

• 100% Direct Drop-in Interchangeability: Precise match to Sun Hydraulics T-10A cavity dimensions and hydraulic curves, allowing seamless retrofits without manifold modifications.

• Floating Construction Technology: Incorporates Sun-style floating construction that isolates internal moving parts from external installation torque stress or cavity machining misalignment, eliminating poppet binding.

• Micro-Finished Hardened Steel Components: Poppets and seating surfaces are vacuum heat-treated and ground to micro-inch tolerances, delivering exceptional wear resistance and zero pressure drift during load-holding.

• 100% Factory Simulated Testing: Every single valve is dynamically bench-tested at rated pressure to verify cracking pressure, flow rate, and leak-tight sealing before dispatch.

Application Areas

• Mobile Construction Machinery: Outrigger locking and boom holding circuits for excavators, rough-terrain cranes, and concrete pumps.

• Industrial Hydraulic Power Units: Pressure-holding manifolds for injection molding machines, stamping presses, and hydraulic clamping tools.

• Agricultural & Specialty Machinery: Combine harvester header control and emergency anti-drop systems on aerial boom lifts.

Expert Maintenance Tips

• Fluid Cleanliness Protocol: Maintain hydraulic fluid cleanliness to ISO 4406 standard 18/16/13 or better. Utilize 10-micron filtration to avoid particulate contamination.

• Calibrated Torque Installation: Always use a calibrated torque wrench. Tighten T-10A cavity cartridges strictly to 45–50 Nm (35–40 lbf·ft) to avoid thread strain or seal distortion.

• O-Ring Seal Protection: Inspect manifold cavity entrance chamfers for burrs before insertion. Pre-lubricate all external O-rings and backup rings with clean hydraulic oil to prevent assembly damage.