RPKC-LAN Sun Hydraulics Relief Valve 350 Bar 380L/min

Product Overview

The RPKC-LAN series pilot-operated balanced piston relief valve (cross-functional with models such as CXBA-XAN, RDFA-LAN, DMDA-MNN, NFBC-LCN, CXFA-XFN, and CXBA-XEV) provides exceptional high-capacity pressure control and overpressure protection in modern hydraulic systems. Built to perfectly match Sun Hydraulics cavity standards (including T-19A, T-13A, and T-10A), this series serves as a 100% direct drop-in replacement without requiring manifold modifications. Constructed with case-hardened alloy steel and Sun-style floating construction, every single valve undergoes 100% factory dynamic simulation testing at 350 bar operating pressure, delivering ultra-low hysteresis, instant response times, and leak-tight load holding under high-flow demand.

Technical Specifications

• Model Codes: RPKC-LAN (Featured series includes CXBA-XAN, RDFA-LAN, DMDA-MNN, NFBC-LCN, CXFA-XFN, CXBA-XEV)

• Standard Cavity: Sun Cavity T-19A (RPKC) / T-13A (CXBA) / T-10A (RDFA)

• Nominal Flow Capacity: 380 L/min (100 gpm) for RPKC-LAN; 120 L/min for CXBA-XAN

• Maximum Operating Pressure: 350 bar (5000 psi)

• Peak Proof Pressure: 420 bar (6090 psi)

• Pressure Setting Range: Range A: 7 – 210 bar (100 – 3000 psi); Range W: 10.5 – 350 bar (150 – 5000 psi)

• Internal Leakage Rate: ≤ 0.7 cc/min at 85% of crack pressure

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

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

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

• Recommended Installation Torque: 200 – 215 Nm (150 – 160 lbf·ft) for T-19A cavity

• Unit Net Weight: Approx. 0.62 kg (1.37 lbs)

Key Technical Advantages

• 100% Direct Drop-in Interchangeability: Precise match to Sun Hydraulics cavity dimensions, threads, and operational curves for seamless field replacement and zero downtime.

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

• Micro-Finished Hardened Steel Components: Poppets and sleeves are vacuum heat-treated and ground to micro-inch tolerances, ensuring exceptional wear resistance and zero pressure drift under high holding loads.

• 100% Dynamic Factory Inspection: 100% batch tested on dynamic test benches under 350 bar working pressure to guarantee cracking pressure accuracy, flow capacity, and zero-leakage seals.

Application Areas

• Heavy Mobile Machinery: Main relief protection in excavators, winch overload circuits in rough-terrain cranes, and wheel loader hydraulics.

• Industrial Hydraulic Presses: Main pump pressure relief and hold-pressure manifolds in plastic injection molding machines and metal presses.

• Mining & Forestry Equipment: High-pressure hydraulic power units in shearers, rock drills, and timber harvesters.

Expert Maintenance Tips

• Fluid Cleanliness Protocol: Maintain system fluid cleanliness to ISO 4406 standard 18/16/13 or cleaner, utilizing 10-micron filtration to avoid particulate contamination on precision seats.

• Calibrated Torque Installation: Always use a calibrated torque wrench. Tighten T-19A cavity cartridges strictly to 200–215 Nm (150–160 lbf·ft) to prevent thread damage or sleeve 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 fluid to prevent seal shearing during assembly.

Examples of optional model suffixes for the core series

CXBA series -XAN, -XBN, -XEN, -XFN
CXDA series -XAN, -XCN, -XDN, -XBN, -XEN, -XFN
CXFA series -XAN, -XCN, -XDN, -XBN, -XEN, -XFN
CXHA series -XAN, -XCN, -XDN, -XBN, -XEN, -XFN
CXJA series -XAN, -XCN, -XDN, -XBN
Other variants include CXCD-XCN, CXED XCN, CXGD-XCN, etc

1. Same flow rate (40L/min, T-162A jack)
CXBA-XAN (NBR seal, Standard)
CXBA-XBN (NBR sealed, Special configuration)
CXBA-XCN (FKM sealed, high temperature resistant/chemical medium resistant)
CXBA-XAV (FKM sealed, non-adjustable)
2. Different flow rates (same structure, different sockets)
CXDA-XAN: 80L/min, T-13A jack, installation torque 41-47Nm
CXFA-XAN: 160L/min, T-5A jack, installation torque 61-68Nm
CXAD-XAN: 30L/min, T-162A jack (free flow: nasal side → nasal tip)
CXHA-XAN: 320L/min, T-18A jack, high-pressure and high-flow working conditions
3. Reverse free flow (nasal side → nasal tip)
CXAD-XAN (30L/min, T-162A)
CXCD-XAN (40L/min, T-162A)
CXED – XAN (80L/min, T-13A)
CXGD-XAN (160L/min, T-5A)