NFCD-LFN Sun Hydraulics Needle Valve T-13A 350 bar 80 L/min

I. NFCD-LFN High Capacity Needle Valve

Product Overview

NFCD-LFN is a high capacity, adjustable needle valve from Sun Hydraulics, featuring a fully adjustable orifice that provides infinite adjustment between fully closed and maximum orifice diameter. The valve uses a T-13A cavity, Series 1 configuration.

The NFCD-LFN provides bidirectional flow regulation through a precision needle design, enabling stepless flow control from fully closed to fully open. This valve is non-pressure compensated—flow is proportional to the square root of the pressure differential across ports 1 and 2. The sharp-edged orifice design minimizes the effects of viscosity on flow variation.

The balanced adjustment mechanism ensures smooth operation even under high-pressure conditions. When the adjustment knob is turned to the fully closed position, the valve exhibits zero leakage. Flow is bidirectional, with the recommended flow direction from port 1 to port 2 to ensure interchangeability with other flow control valves.

As a direct replacement solution for Sun Hydraulics original products, this product strictly complies with Sun Hydraulics technical standards and offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing prior to shipment, ensuring performance reliability and long-term operational stability under actual working conditions.

Technical Specifications

• Model: NFCD-LFN

• Product Type: High Capacity Needle Valve

• Cavity: T-13A

• Series: 1

• Capacity: 80 L/min (20 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Adjustment (CCW Turns from Fully Closed to Fully Open) : 5

• Valve Hex Size: 22.2 mm (7/8 in)

• Valve Installation Torque: 41 – 47 Nm (30 – 35 lbf ft)

• Adjustment Screw Internal Hex Size: 4 mm (5/32 in)

• Locknut Hex Size: 15 mm (9/16 in)

• Locknut Torque: 9 – 10 Nm (80 – 90 lbf in)

• Model Weight: Approx. 0.15 kg (0.30 lb)

• Seal Kits: Buna 990010007 / EPDM 990010014 / Polyurethane 990010002 / Viton 990010006

Key Technical Advantages

1. Fully Adjustable Needle Design – Precise Stepless Flow Control
The fully adjustable orifice design provides infinite adjustment between fully closed and maximum orifice diameter. Whether requiring minimal bleed flow or full open flow, precise control is achieved through the adjustment mechanism.

2. Bidirectional Flow Capability – Versatile Circuit Layout
Flow is bidirectional. The recommended flow direction is port 1 → port 2 to ensure interchangeability with other flow control valves. This bidirectional capability enables flexible adaptation to forward throttling and reverse blocking applications.

3. Zero Leakage When Fully Closed – Reliable Shut-Off
When the adjustment knob is turned to the closed position, the valve exhibits zero leakage. This makes it suitable as a reliable shut-off valve for applications requiring complete flow blocking.

4. Balanced Adjustment Mechanism – Smooth Operation Under High Pressure
The balanced adjustment mechanism ensures smooth, effortless adjustment even under 350 bar high pressure. This eliminates adjustment difficulty or binding under high differential pressure.

5. Sharp-Edged Orifice Design – Minimized Viscosity Effects
The sharp-edged orifice design minimizes the effects of viscosity on flow variation. Flow remains relatively stable even when fluid temperature changes cause viscosity fluctuations.

6. Sun Floating Style Construction – Eliminates Installation Stress
Incorporates Sun Hydraulics’ patented floating style construction to eliminate the risk of internal binding from excessive installation torque or cavity/cartridge machining variations.

Application Areas

• Hydraulic System Flow Regulation: Precise control of actuator speeds

• Bypass Throttling Control: Regulating分流 flow in bypass circuits

• Shut-Off Valve Applications: Complete flow blocking when needed

• Speed Control Circuits: Regulating cylinder or motor speeds

• Test Equipment: Precise flow adjustment for hydraulic test benches

• Lubrication Systems: Precise control of lubricant flow rates

Expert Maintenance Tips

1. Cavity Cleaning
Thoroughly clean the T-13A cavity prior to installation. Inspect O-ring seals for aging or damage—replace after every disassembly.

2. Installation Torque
T-13A cavity installation torque: 41 – 47 Nm (30 – 35 lbf ft) . Use a torque wrench to avoid valve body distortion or spool binding.

3. Adjustment Direction
From fully closed to fully open requires 5 counterclockwise turns. Adjust slowly to avoid impact.

4. Flow Direction
Recommended flow direction is port 1 to port 2. While bidirectional, following the recommended flow direction ensures optimal interchangeability.

5. Seal Material Selection
Standard NBR seals are for mineral oil-based fluids. EPDM seals are required for phosphate ester fluids—EPDM seals must not be exposed to petroleum-based fluids or greases. Polyurethane seals are for high-wear applications.

6. Scheduled Maintenance
Perform functional checks every 2,000 operating hours.

II. CWEA-LHN Counterbalance Valve with External Drain

Product Overview

CWEA-LHN is a counterbalance valve with external drain from Sun Hydraulics, featuring a 3:1 pilot ratio and T-22A cavity.

Counterbalance valves (also known as motion control or over-center valves) control overrunning loads. A check valve allows free flow from the directional valve (port 2) to the load (port 1), while a direct-acting, pilot-assisted relief valve controls flow from port 1 to port 2. Pilot pressure at port 3 lowers the effective relief setting at the 3:1 pilot ratio.

The “LHN” code indicates external drain configuration with 1.7 bar check valve cracking pressure (“H” indicates high cracking pressure). This design makes the valve insensitive to tank port back pressure, particularly suitable for applications with high return line back pressure.

As a direct replacement solution for Sun Hydraulics original products, this product offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: CWEA-LHN

• Product Type: Counterbalance Valve with External Drain

• Pilot Ratio: 3:1

• Cavity: T-22A

• Capacity: 120 L/min (30 gpm)

• Maximum Setting: 280 bar (4000 psi)

• Maximum Recommended Load Pressure at Max. Setting: 215 bar (3075 psi)

• Factory Setting Flow: 30 cc/min

• Maximum Valve Leakage at Reseat: 5 drops/min

• Check Cracking Pressure: 1.7 bar

• Weight: Approx. 0.36 kg

Key Technical Advantages

1. 3:1 Pilot Ratio – Precise Load Control
The 3:1 pilot ratio means pilot pressure at port 3 lowers the effective relief setting at a 3:1 rate. Operators can control high load pressures with relatively low pilot pressures for smooth load lowering and excellent feel.

2. Integrated Check Valve – Free Flow to Load
An integrated check valve allows free flow from the directional valve (port 2) to the load (port 1). The 1.7 bar cracking pressure (“H” code) effectively prevents cavitation during actuator startup.

3. External Drain Design – Back Pressure Immunity
The external drain design makes the valve insensitive to tank port (port 2) back pressure. In systems with high return line back pressure, this ensures the valve setting is unaffected by back pressure for precise and reliable control.

4. Pilot-Assisted Direct-Acting Relief – Precise Pressure Control
The relief section uses a direct-acting, pilot-assisted design for fast response and high control accuracy. Direct-acting response is faster than pure pilot-operated designs under sudden load changes.

5. High Reseat Ratio – Reliable Closing
The valve reliably closes after pressure decay to prevent load drift, ensuring system safety and positioning accuracy.

6. Sun Floating Style Construction
Incorporates Sun’s patented floating style construction to eliminate internal binding.

Application Areas

• Hydraulic Cylinder Overrunning Load Control: Preventing uncontrolled load descent under gravity

• Hydraulic Motor Braking Control: Smooth deceleration and stopping under load

• Cranes & Lifting Platforms: Preventing unintended boom or platform descent

• Mobile Machinery: Motion control for excavator boom, arm, and other actuators

• Injection Molding: Smooth clamping control and safety locking

• Machine Tools: Smooth table feed control

Expert Maintenance Tips

1. Setting Pressure Safety Margin
Counterbalance valves should be set at least 1.3 times the maximum load-induced pressure.

2. Adjustment Direction
Turn clockwise to decrease setting, counterclockwise to increase. Fully reduced setting is 200 psi (14 bar) .

3. Pilot Pressure vs. Setting Relationship
Port 3 pilot pressure lowers the effective setting at the 3:1 pilot ratio. Understand this relationship during system commissioning.

4. Seal Inspection
Inspect O-ring seals after every disassembly—replace if aged or damaged.

5. Scheduled Maintenance
Perform functional testing every 2,000 operating hours.

III. RPEC-LEN-HT88 Pilot-Operated Relief Valve

Product Overview

RPEC-LEN-HT88 is a pilot-operated, balanced piston relief valve from Sun Hydraulics. The valve uses a T-10A cavity, Series 1 configuration. The HT88 suffix is presumed to be an internal configuration or date code.

RPEC-LEN is a normally closed pressure regulating valve. When inlet (port 1) pressure reaches the valve setting, the valve opens to tank (port 2) , throttling flow to regulate pressure. These valves are accurate, have low pressure rise vs. flow, are smooth and quiet, and are moderately fast.

Port 2 accepts full pressure, making the valve suitable for cross-port relief circuits. The main stage orifice is protected by a 150-micron stainless steel screen. Not suitable for load holding applications. Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.

As a direct replacement solution for Sun Hydraulics original products, this product offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: RPEC-LEN-HT88

• Product Type: Pilot-operated Balanced Piston Relief Valve

• Cavity: T-10A

• Series: 1

• Capacity: 95 L/min (25 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Factory Pressure Setting Established at: 15 L/min (4 gpm)

• Response Time: Approx. 10 ms

• Maximum Leakage (110 SUS / 24 cSt) : 30 cc/min @ 70 bar

• Adjustment (CW Turns from Min. to Max.) : 5

• Valve Hex Size: 22.2 mm (7/8 in)

• Valve Installation Torque: 41 – 47 Nm (30 – 35 lbf ft)

• Adjustment Screw Internal Hex Size: 4 mm (5/32 in)

• Locknut Torque: 9 – 10 Nm

• Model Weight: Approx. 0.15 kg (0.30 lb)

• Seal Kits: Buna 990010007 / EPDM 990010014 / Polyurethane 990010002 / Viton 990010006

Key Technical Advantages

1. Pilot-Operated Balanced Piston – High Accuracy & Low Pressure Rise
The pilot-operated balanced piston design delivers high pressure regulation accuracy with minimal pressure rise versus flow. Pressure remains precisely controlled even under significant flow fluctuations.

2. 150-Micron Stainless Steel Screen – Reliable Orifice Protection
The main stage orifice is protected by a 150-micron stainless steel screen. This effectively prevents particulate contamination from entering the pilot stage, reducing the risk of pressure response lag and setpoint drift.

3. Full Pressure at Port 2 – Suitable for Cross-Port Relief Circuits
Port 2 (tank port) accepts full pressure (350 bar) , making the valve particularly suitable for cross-port relief circuits. However, spool leakage must be carefully considered.

4. Fast, Smooth & Quiet Operation
Typical response time is approximately 10 ms with smooth and quiet operation. Provides reliable pressure control and a comfortable working environment in fast-response systems.

5. Sun Floating Style Construction
Incorporates Sun’s patented floating style construction to eliminate internal binding from excessive installation torque or cavity/cartridge machining variations.

6. Not Suitable for Load Holding
Due to inherent spool leakage, this valve is not suitable for load holding applications. For load holding, use pilot-operated check valves or counterbalance valves.

Application Areas

• Hydraulic System Overpressure Protection: Main system relief or branch circuit safety valves

• Cross-Port Relief Circuits: Bidirectional overpressure protection

• Load Sensing Systems: Pressure limiting valves for maximum system pressure

• Mobile Machinery: Overpressure protection for construction and agricultural equipment

• Industrial Hydraulic Systems: Pressure limiting for injection molding machines, presses

• Test Equipment: Precise pressure setting for hydraulic test benches

Expert Maintenance Tips

1. Cavity Cleaning
Thoroughly clean the T-10A cavity prior to installation. Inspect O-ring seals.

2. Installation Torque
T-10A cavity installation torque: 41 – 47 Nm (30 – 35 lbf ft) .

3. Port 2 Back Pressure – 1:1 Additive Effect
Back pressure at port 2 is directly additive to the valve setting at a 1:1 ratio. Consider system return back pressure when setting the valve.

4. Seal Material Selection
Standard NBR seals are for mineral oil-based fluids. EPDM seals are required for phosphate ester fluids.

5. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours.

IV. RVGA-LCN-HT88 Ventable Pilot-Operated Relief Valve

Product Overview

RVGA-LCN-HT88 is a ventable, pilot-operated balanced piston relief valve from Sun Hydraulics. The valve uses a T-17A cavity, Series 3 configuration. The HT88 suffix is presumed to be an internal configuration or date code.

RVGA-LCN is a normally closed pressure regulating valve. When inlet (port 1) pressure reaches the valve setting, the valve opens to tank (port 2) , throttling flow to regulate pressure. A vent port (port 3) is provided between the main piston and pilot stage, enabling remote control via external pilot or 2-way valves.

RVGA-LCN is accurate, has low pressure rise vs. flow, is smooth and quiet, and is moderately fast. Port 2 accepts full pressure, making it suitable for cross-port relief circuits. The main stage orifice is protected by a 150-micron stainless steel screen. Not suitable for load holding applications. Back pressure on port 2 is directly additive to the valve setting at a 1:1 ratio.

As a direct replacement solution for Sun Hydraulics original products, this product offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: RVGA-LCN-HT88

• Product Type: Ventable Pilot-operated Balanced Piston Relief Valve

• Cavity: T-17A

• Series: 3

• Capacity: 240 L/min (60 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Weight: Approx. 0.70 kg (1.60 lb)

• Seal Kits: Viton 990017006（Buna and other options available）

Key Technical Advantages

1. Vent Port (Port 3) – Flexible Remote Control
A vent port (port 3) is provided between the main piston and pilot stage. By connecting a remote pilot relief or 2-way valve to port 3, the valve can be controlled remotely below its own setting. This offers exceptional flexibility for multi-point pressure control and remote pressure adjustment.

2. Pilot-Operated Balanced Piston – High Accuracy & Low Pressure Rise
The pilot-operated balanced piston design delivers high accuracy with minimal pressure rise versus flow. Pressure remains precisely controlled even under significant flow fluctuations.

3. 150-Micron Stainless Steel Screen – Reliable Orifice Protection
The main stage orifice is protected by a 150-micron stainless steel screen. This prevents particulate contamination from entering the pilot stage, reducing the risk of pressure response lag and setpoint drift.

4. High Flow Capacity – 240 L/min
RVGA-LCN delivers 240 L/min (60 gpm) flow capacity in the T-17A cavity. This high capacity meets the relief requirements of large hydraulic systems.

5. Full Pressure at Port 2 – Suitable for Cross-Port Relief Circuits
Port 2 accepts full pressure (350 bar) , making the valve particularly suitable for cross-port relief circuits. However, spool leakage must be carefully considered.

6. Sun Floating Style Construction
Incorporates Sun’s patented floating style construction to eliminate internal binding.

Application Areas

• Large Hydraulic System Overpressure Protection: Main system relief or high-flow branch circuit safety protection

• Cross-Port Relief Circuits: Bidirectional overpressure protection

• Remote Pressure Control: Remote pressure setting via port 3 with external pilot valves

• Mobile Machinery: Overpressure protection for construction and agricultural equipment

• Industrial Hydraulic Systems: Pressure limiting for injection molding, presses, metallurgical equipment

• Test Equipment: Precise pressure setting for hydraulic test benches

Expert Maintenance Tips

1. Cavity Cleaning
Thoroughly clean the T-17A cavity prior to installation. Inspect O-ring seals.

2. Installation Torque
T-17A cavity installation torque—refer to Sun Hydraulics technical data sheet for specific values (typically higher due to cavity size). Use a torque wrench.

3. Port 3 Remote Control
Remote pressure control is achieved via an external pilot valve connected to port 3. Pressure at port 3 affects the valve setting at a 1:1 ratio. Understand this relationship before use.

4. Port 2 Back Pressure – 1:1 Additive Effect
Back pressure at port 2 is directly additive to the valve setting at a 1:1 ratio. Consider system return back pressure when setting the valve.

5. Seal Material Selection
Standard NBR seals are for mineral oil-based fluids. EPDM or Viton seals are required for phosphate ester fluids.

6. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours.