PVAPVV41V20 PVAPVV43N20 PVAPVV43V20 Parker Preload Valve 400 bar

Product Overview

The PVAPVV series preload manifolds are dedicated pressure control accessories engineered by Parker Hannifin for the PV series axial piston pumps. As a preload valve (Vorspannventil) , the PVAPVV series provides the minimum system back pressure (approx. 20 bar) required for proportional-controlled PV variable displacement pumps to reliably regulate displacement under low-load or small-displacement conditions.

The PVAPVV series covers models including PVAPVV41V20, PVAPVV43N20, PVAPVV43V20, PVAPVV44N20, and PVAPVV51N20, featuring ISO 6162 standard flange connections for direct mounting onto the pressure port of PV series pumps. Valve bodies are manufactured from high-strength cast iron with optimized internal flow paths, ensuring minimal pressure loss (<1 bar) across the full flow range.

Our complete range of Parker PVAPVV preload manifolds strictly adheres to OEM technical standards, achieving 100% direct interchangeability with original components. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring performance parameters are fully consistent with genuine Parker products. Direct replacement significantly reduces equipment downtime and maintenance costs.

⚠️ Product Function Note:

• The PVAPVV series is a preload manifold rather than a conventional “pressure regulating valve.” Its core function is to provide stable minimum system back pressure for the proportional displacement control of PV pumps.

• Together with the PVCM series (pressure compensator), PVCP series (pressure cutoff), and PVCR series (remote pressure control), the PVAPVV series belongs to the Parker PV pump control accessory family.

⚠️ Model Code Decoding:

• PVAPVV = Preload Valve / Vorspannventil

• 41 / 43 / 44 / 51 = Pump displacement size code (41 ≈ PV140, 43 ≈ PV180, 44 ≈ PV180/270, 51 ≈ PV270)

• V / N = Seal material (V = FPM, N = NBR)

• 20 = Design/thread specification (20 = BSPP metric)

Technical Specifications 

PVAPVV Series General Specifications

• Product Series: Parker PVAPVV series preload manifold

• Product Type: Preload Manifold / Vorspannventil

• Brand: Parker Hannifin

• Compatible Pump Series: Parker PV series axial piston pumps (PVplus series, Design Series 44-47)

• Maximum Operating Pressure: 400 bar

• Maximum Flow Capacity: 550 L/min

• Cracking Pressure: Approx. 20 bar

• Full Opening Pressure: Approx. 25–30 bar system pressure

• Pressure Drop at Full Opening: < 1 bar

• Mounting Type: Flange connection

• Interface Standard: ISO 6162

• Mounting Location: Directly on PV pump pressure port

• Seal Material: NBR (code N) or FPM/FKM (code V)

• Thread Option: BSPP metric (code 20)

• Compatible Hydraulic Fluids: Mineral-based hydraulic oils per DIN 51524

Model Specifications Overview

• PVAPVV41V20: Compatible with PV140 pump, FPM seals, BSPP thread

• PVAPVV43N20: Compatible with PV180 pump, NBR seals, BSPP thread

• PVAPVV43V20: Compatible with PV180 pump, FPM seals, BSPP thread

• PVAPVV44N20: Compatible with PV180/PV270 pumps, NBR seals, BSPP thread

• PVAPVV51N20: Compatible with PV270 pump, NBR seals, BSPP thread

Key Technical Advantages

1. Provides Stable Minimum Back Pressure for Proportional-Controlled PV Pumps
Proportional displacement control of PV series variable pumps relies on pump outlet pressure to overcome return spring force and actuate the displacement control mechanism. Under low-load or small-displacement conditions, the system cannot self-generate sufficient back pressure, preventing proper pump displacement regulation. The PVAPVV preload valve establishes a stable back pressure of approximately 20 bar at the pump outlet, ensuring reliable proportional control functionality under all operating conditions.

2. Minimal Pressure Drop for Maximum System Efficiency
The preload valve exhibits a pressure drop of less than 1 bar when fully open (at system pressures of approximately 25–30 bar). This means that within the normal operating pressure range, the energy loss caused by the preload valve is virtually negligible and does not compromise overall system efficiency.

3. Compact Flange Connection Design for Simplified System Integration
The PVAPVV preload valve features ISO 6162 standard flange connections for direct mounting onto the PV pump pressure port. No additional piping or mounting brackets are required, greatly simplifying system integration. The preload manifold also provides an auxiliary pressure port (Mp1) for supplying pilot control oil to downstream components such as directional valves.

4. Multiple Size Options Covering the Full PV Pump Range
The PVAPVV preload valve is available in 41, 43, 44, and 51 size codes, corresponding to PV140, PV180, and PV270 displacement variants of the PV series. Seal material options include NBR and FPM to accommodate different hydraulic fluid types.

5. 100% Direct Interchangeability and Simulated Condition Testing
All models strictly adhere to Parker original mounting dimensions and interface standards (ISO 6162), enabling direct drop-in replacement of original preload valves without piping modification or system adjustment. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring consistent, stable performance at rated pressure and flow.

Application Areas

• Proportional Displacement Control of PV Series Variable Pumps: Provides stable back pressure for FDV (FPV) proportional displacement control

• Low-Load/Small-Displacement Conditions: Applications where the system cannot self-generate sufficient back pressure

• Mobile Machinery Hydraulic Systems: PV pump control for excavators, wheel loaders, and other construction equipment

• Industrial Hydraulic Systems: PV pump proportional control for injection molding machines, presses, and other equipment

• Systems Requiring Pilot Control Oil Supply: Utilizing the Mp1 port of the preload valve to supply pilot oil to directional valves

Expert Maintenance Tips

1. Verify Model and Pump Compatibility Prior to Installation
The PVAPVV preload valve size code (41/43/44/51) is directly correlated with the PV pump displacement. Confirm that the preload valve model matches the pump displacement—for example, PVAPVV41V20 is compatible with PV140 pumps, while PVAPVV51N20 is compatible with PV270 pumps. Mismatched models will result in incorrect flange interface dimensions or insufficient flow capacity.

2. Flange Installation Torque and Sealing
The preload valve features ISO 6162 standard flange connections. Use a torque wrench to evenly tighten flange bolts to the torque values specified in Parker technical manuals. Use OEM-specification O-rings for sealing—inspect seal condition prior to installation and replace if worn or damaged.

3. System Cleanliness Management
The PVAPVV preload valve features precision internal flow paths and demands adequate oil cleanliness. Recommended system cleanliness: ISO 4406 Class 18/16/13 or higher. Thoroughly flush system piping prior to installation.

4. Use of Auxiliary Port (Mp1)
The preload manifold is equipped with an auxiliary pressure port Mp1 for supplying pilot control oil to downstream components such as directional valves. If using this port, ensure that the pilot oil consumption of downstream components remains within the supply capacity of the preload valve to avoid compromising normal preload valve operation.

5. Periodic Functional Checks
Perform functional checks every 2,000 operating hours or annually to verify that the preload valve cracking pressure remains at approximately 20 bar and that pressure drop at full opening is less than 1 bar. If cracking pressure drift or abnormal pressure drop increase is observed, arrange for servicing or replacement.