PVDA-LAN Sun Hydraulics Pressure Reducing Valve 350 bar 40 L/min

I. PVDA-LAN / PVFA-LAN / PVHA-LAN / PVJA-LAN Pilot-Operated Pressure Reducing/Relieving Valves

Product Overview

PVDA-LAN, PVFA-LAN, PVHA-LAN, and PVJA-LAN are pilot-operated, 3-way pressure reducing/relieving valves from Sun Hydraulics with external drain to port 4 . These valves reduce a high primary pressure at the inlet (port 2) to a constant reduced pressure at port 1, with a full-flow relief function from port 1 to tank (port 3).

The key advantage of this series is the external drain port (port 4) , which makes these valves insensitive to pressure at tank (port 3) . Port 4 also serves as a remote control port —connecting an external pilot valve or 2-way valve enables remote pressure setting.

Models are differentiated by capacity and cavity:

• PVDA-LAN: 40 L/min, T-21A cavity

• PVFA-LAN: 80 L/min, T-22A cavity

• PVHA-LAN: 160 L/min, T-23A cavity

• PVJA-LAN: 320 L/min, T-24A cavity

As a direct replacement solution for Sun Hydraulics original products, this series strictly complies with Sun Hydraulics technical standards and offers complete interchangeability—direct drop-in replacement without any modification to manifold cavities or piping connections. 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

PVDA-LAN

• Model: PVDA-LAN

• Product Type: Pilot-operated 3-way pressure reducing/relieving valve with drain to port 4

• Cavity: T-21A

• Series: 1

• Capacity: 40 L/min (10 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Control Pilot Flow: 7 – 10 in³/min (0.11 – 0.16 L/min)

• 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)

• Locknut Torque: 9 – 10 Nm

• Weight: Approx. 0.20 kg (0.45 lb)

• Seal Kits: Buna 990021007 / Viton 990021006

PVFA-LAN

• Model: PVFA-LAN

• Product Type: Pilot-operated 3-way pressure reducing/relieving valve with drain to port 4

• Cavity: T-22A

• Series: 2

• Capacity: 80 L/min (20 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Control Pilot Flow: 10 – 15 in³/min (0.16 – 0.25 L/min)

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

• Valve Hex Size: 28.6 mm (1-1/8 in)

• Valve Installation Torque: 61 – 68 Nm (45 – 50 lbf ft)

• Locknut Torque: 9 – 10 Nm

• Weight: Approx. 0.34 kg (0.74 lb)

• Seal Kits: Buna 990022007 / Viton 990022006 / Polyurethane 990022002

PVHA-LAN

• Model: PVHA-LAN

• Product Type: Pilot-operated 3-way pressure reducing/relieving valve with drain to port 4

• Cavity: T-23A

• Series: 3

• Capacity: 160 L/min (40 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Control Pilot Flow: 15 – 20 in³/min (0.25 – 0.33 L/min)

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

• Valve Hex Size: 31.8 mm (1-1/4 in)

• Valve Installation Torque: 203 – 217 Nm (150 – 160 lbf ft)

• Locknut Torque: 9 – 10 Nm

• Weight: Approx. 0.70 kg (1.55 lb)

• Seal Kits: Buna 990023007 / Viton 990023006 / EPDM 990023014 / Polyurethane 990023002

PVJA-LAN

• Model: PVJA-LAN

• Product Type: Pilot-operated 3-way pressure reducing/relieving valve with drain to port 4

• Cavity: T-24A

• Series: 4

• Capacity: 320 L/min (80 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Control Pilot Flow: 15 – 20 in³/min (0.25 – 0.33 L/min)

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

• Valve Hex Size: 41.3 mm (1-5/8 in)

• Valve Installation Torque: 474 – 508 Nm (350 – 375 lbf ft)

• Locknut Torque: 9 – 10 Nm

• Weight: Approx. 1.40 kg (3.10 lb)

• Seal Kits: Buna 990024007 / Viton 990024006 / EPDM 990024014 / Polyurethane 990024002

Key Technical Advantages

1. Integrated Reducing & Relieving Functions in One Valve
This series combines pressure reducing and relieving functions in a single cartridge—operating as a reducing valve under normal conditions and automatically transitioning to full-flow relief from port 1 to tank (port 3) when port 1 pressure rises abnormally. This eliminates the need for a separate relief valve in the circuit.

2. External Drain (Port 4) – Back Pressure Immunity & Remote Control
The external drain port (port 4) makes the valve insensitive to tank port (port 3) back pressure. Port 4 also serves as a remote control port —connecting an external pilot valve enables remote pressure setting, with pressure at port 4 directly additive at a 1:1 ratio to the valve setting.

3. Extremely Low Dead-Band & Superior Regulation Characteristics
The pilot-operated design delivers very low dead-band transition between reducing and relieving modes, with exceptionally flat pressure/flow characteristics, excellent stability, and low hysteresis. These characteristics ensure precise reduced pressure control even under significant load fluctuations.

4. Sun Floating Style Construction – Eliminates Binding from Installation Stress
The spool assembly incorporates Sun Hydraulics’ patented floating style construction, allowing internal parts to float within the cavity. This effectively eliminates the risk of internal binding caused by excessive installation torque or cavity/cartridge machining variations.

5. Four Capacity Options – Adapts to Diverse System Requirements
The series covers a broad flow range from 40 L/min (PVDA-LAN) to 320 L/min (PVJA-LAN), compatible with four standard cavities: T-21A, T-22A, T-23A, and T-24A.

Application Areas

• Hydraulic Branch Circuit Pressure Reduction: Providing differentiated stable low-pressure supplies to various system branches

• Pilot Control Circuits: Stable pilot pressure supply for pilot and proportional valves

• Load Sensing Systems: Pressure compensation to maintain actuator speed independent of load variations

• Injection Molding Machinery: Precision control of multi-stage injection pressures

• Machine Tool Hydraulic Systems: Precision pressure control for clamping, tool change, and auxiliary functions

• Mobile Machinery: Stable pressure supply for implement control circuits

• Test Equipment: Multi-stage pressure setting for hydraulic test benches

Expert Maintenance Tips

1. Cavity Cleaning
Thoroughly clean the manifold cavity (T-21A / T-22A / T-23A / T-24A) prior to installation. Inspect O-ring seals for aging or damage.

2. Strict Torque Control
Installation torque varies by model and must strictly follow specified values:

• PVDA-LAN (T-21A) : 41 – 47 Nm

• PVFA-LAN (T-22A) : 61 – 68 Nm

• PVHA-LAN (T-23A) : 203 – 217 Nm

• PVJA-LAN (T-24A) : 474 – 508 Nm

3. Port 4 (Drain) Back Pressure – 1:1 Additive Effect
Pressure at port 4 is directly additive to the valve setting at a 1:1 ratio and must not exceed 350 bar. Consider port 4 back pressure when setting the valve.

4. Port 3 (Tank) Pressure Limit
Port 3 pressure should be limited to 210 bar.

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. Polyurethane seals are for high-wear applications.

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

• Verify reduced pressure matches set value

• Verify relieving function operates correctly

• Check port 4 connections for leakage

• Inspect O-ring seals for aging or damage

II. CBCA-LAN Counterbalance Valve

Product Overview

CBCA-LAN is a standard capacity counterbalance valve from Sun Hydraulics with 3:1 pilot ratio and T-11A 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 a rate determined by the 3:1 pilot 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: CBCA-LAN

• Product Type: Counterbalance Valve

• Pilot Ratio: 3:1

• Cavity: T-11A

• Series: 1

• Capacity: 60 L/min (15 gpm)

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

• Maximum Setting: 280 bar (4000 psi)

• Factory Pressure Setting Established at: 30 cc/min (2 in³/min)

• Maximum Valve Leakage at Reseat: 0.3 cc/min (5 drops/min)

• Adjustment (CCW Turns from Min. to Max.) : 3.75

• Reseat: >85% of setting

• Valve Hex Size: 22.2 mm (7/8 in)

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

• Weight: Approx. 0.15 – 0.20 kg

• Seal Kits: Buna 990011007 / Viton 990011006

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. This enables operators to 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), ensuring rapid actuator response without additional pressure drop.

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

4. High Reseat Ratio – Reliable Closing
CBCA-LAN offers a reseat ratio >85% of setting, ensuring the valve reliably closes after pressure decay to prevent load drift and ensure system safety and positioning accuracy.

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

Application Areas

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

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

• Cranes & Lifting Platforms: Preventing boom or platform unintended 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. Port 2 Back Pressure Effect
Back pressure at port 2 adds to the effective relief setting at a ratio of (1 + pilot ratio) × back pressure. Ensure adequate return line sizing.

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. Adjustment Direction
Turn clockwise to decrease setting, counterclockwise to increase. Full clockwise setting is below 14 bar.

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

III. CXED-XAN Check Valve

Product Overview

CXED-XAN is a free flow side to nose check valve from Sun Hydraulics with T-5A cavity.

This 2-port on/off circuit component allows free flow from inlet (port 2) to outlet (port 1) and blocks flow in the opposite direction. CXED series check valves are known for extremely low leakage—maximum leakage of less than 1 drop per minute (0.07 cc/min) . Cracking pressure is 0.3 bar.

CXED-XAN is often used as a circuit saver to correct incorrect manifold drillings. The side-to-nose flow path (port 2→port 1) has approximately 30% less capacity than preferred nose-to-side models.

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: CXED-XAN

• Product Type: Check Valve

• Flow Direction: Free flow side to nose (port 2 → port 1)

• Cracking Pressure: 0.3 bar

• Cavity: T-5A

• Series: 2

• Capacity: 120 L/min (30 gpm)

• Maximum Operating Pressure: 350 bar (5000 psi)

• Maximum Leakage (110 SUS / 24 cSt) : 0.07 cc/min (1 drop/min)

• Valve Hex Size: 28.6 mm (1-1/8 in)

• Valve Installation Torque: 61 – 68 Nm (45 – 50 lbf ft)

• Weight: Approx. 0.17 kg (0.37 lb)

• Seal Kits: Buna 990203007 / Viton 990203006

Key Technical Advantages

1. Extremely Low Leakage – Less than 1 Drop/Minute
Maximum leakage is less than 1 drop per minute (0.07 cc/min) . This makes CXED series ideal for long-term pressure holding applications.

2. 350 Bar Full Pressure Capability
Both ports 1 and 2 accept 350 bar (5000 psi) full pressure.

3. Side-to-Nose Flow Path – Flexible Circuit Layout
The side-to-nose flow path complements nose-to-side models for flexible manifold layout, particularly suited for space-constrained or complex drilling applications.

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

Application Areas

• Hydraulic Locking Circuits: Preventing actuator movement after pressure loss

• Accumulator Isolation: Preventing reverse leakage from accumulators

• Pump Outlet Protection: Preventing reverse pressure shock to pumps

• Bypass Check Valves: Providing alternate paths around filters or coolers

• Circuit Saver: Correcting incorrect manifold drillings

• Load Holding Circuits: Preventing unintended load descent

Expert Maintenance Tips

1. Flow Direction Verification
Confirm correct flow direction—CXED-XAN allows flow from side (port 2) to nose (port 1) . Reverse installation will block flow.

2. Installation Torque
CXED-XAN (T-5A) installation torque: 61 – 68 Nm (45 – 50 lbf ft) .

3. Leakage Testing
After installation, perform leakage testing at system operating pressure. Maximum leakage is less than 1 drop/minute.

4. Seal Replacement
Replace seals after every disassembly. Standard NBR seals are for mineral oil-based fluids. Viton seals are required for phosphate ester fluids.

5. Scheduled Functional Check
Perform functional checks every 2,000 operating hours.