SPVF-40-A2F-1A25 | KRACHT Pressure Relief Valve 450L/min 25bar

Product Overview

The SPVF-40-A2F-1A25 is a classic model in the KRACHT SPVF series of direct-operated pressure relief valves. KRACHT is a globally renowned German manufacturer of hydraulic components with over 40 years of experience in compact hydraulic systems. The SPV/SPVF series of direct-operated sliding piston pressure relief valves are widely used in industrial hydraulics and lubrication technology.

The SPVF series is a direct-operated sliding piston relief valve for pipeline installation, designed to safeguard low-pressure hydraulic circuits. The SPVF-40-A2F-1A25 features SAE 3000 psi flange connection and is ATEX Zone 2/21 certified for explosion-proof applications in petrochemical and other hazardous environments. The valve body is constructed from EN-GJL 300 cast iron for superior strength and sealing performance.

Model Code Breakdown (SPVF-40-A2F-1A25):

• SPVF: Direct-operated Pressure Relief Valve

• 40: Nominal Size 40, Qmax 450 L/min

• A: Standard version, NBR seals

• 2F: SAE 3000 psi flange connection

• 1: Construction code (specified by KRACHT)

• A: Set screw adjustment

• 25: Pressure stage (19–25 bar)

Technical Specifications 

SPVF-40-A2F-1A25 Specifications:

• Model: SPVF-40-A2F-1A25

• Brand: KRACHT (Germany)

• Product Type: Direct-operated Pressure Relief Valve

• Valve Type: Sliding Piston Valve

• Installation Type: Pipeline Installation

• Nominal Size: 40 (Qmax 450 L/min)

• Maximum Flow Rate: 450 L/min (119 GPM) 

• Maximum Operating Pressure: 20 bar (290 psi) (intermittent 30 bar / 435 psi)

• Pressure Setting Range: 19–25 bar (A25 pressure stage)

• Adjustment Type: Hexagon socket set screw

• Connection Standard: SAE Flange (3000 psi) 

• Body Material: EN-GJL 300 Cast Iron

• Seal Material: NBR (standard)

• Media Temperature Range: -40°C to +220°C

• Ambient Temperature Range: -40°C to +60°C

• Response Time: ≤50 ms

• Explosion Protection: ATEX Zone 2/21

• Compatible Fluids: Mineral oil, synthetic hydraulic oil, lubricating oil

Key Technical Advantages

1. Direct-Operated Sliding Piston Design for Fast Response

The SPVF-40-A2F-1A25 features direct spring-operated sliding piston construction. Compared to pilot-operated relief valves, the direct-operated design eliminates the pilot stage for faster response ( ≤50 ms ), making it ideal for low-pressure hydraulic systems requiring rapid pressure relief.

2. 450 L/min High Flow Capacity

The SPVF-40-A2F-1A25 delivers 450 L/min maximum flow at nominal size 40. This places it at the forefront of direct-operated relief valves in its class, suitable for pressure protection in diverse low-pressure, high-flow hydraulic systems.

3. ATEX Explosion-Proof Certification for Hazardous Environments

The SPVF-40-A2F-1A25 is ATEX Zone 2/21 certified. The valve encloses components that could ignite explosive gas mixtures in a flameproof housing capable of containing internal explosions without igniting the external atmosphere—ideal for petrochemical, mining, and other hazardous applications.

4. Wide Temperature Range with Superior Corrosion Resistance

Media temperature range covers -40°C to +220°C, suitable for diverse extreme conditions from arctic cold to high-temperature operations. The EN-GJL 300 cast iron body provides excellent strength and corrosion resistance. Compatible with mineral oil, synthetic hydraulic oil, and lubricating oil.

5. Modular Design with Flexible Connection Options

The SPVF series features modular design with CFD-optimized flow paths for minimal pressure drop and high pressure-setting accuracy. Available with SAE flange (3000 psi) and Whitworth pipe thread (G) connection options to flexibly accommodate diverse piping design requirements.

Application Areas

• Industrial Hydraulic Systems — Pressure setting and safety protection for low-pressure hydraulic circuits

• Lubrication Systems — Pressure control and system protection for lubrication circuits

• Construction Machinery — Low-pressure circuit protection for excavators, loaders, and mobile equipment

• Metallurgical Equipment — Pressure control for rolling mills and heavy-duty systems

• Marine and Port Machinery — Low-pressure circuit protection for marine hydraulic systems

• Petrochemical Industry — ATEX-certified explosion-proof applications in hazardous environments

• Automotive and Energy — Hydraulic control for automotive manufacturing and energy equipment

Expert Maintenance Tips

1. Installation Guidelines

• SPVF-40-A2F-1A25 is a pipeline-mounted relief valve—ensure correct piping connections (P port to pressure line, T port to return line).

• Connection standard is SAE flange (3000 psi) —ensure flange bolts are evenly torqued and O-ring seals are intact.

• Thoroughly clean piping and ports before installation to prevent foreign particles from entering and causing piston sticking or seal damage.

• Vertical installation (adjustment direction downward) is recommended.

2. Pressure Setting Adjustment

• SPVF-40-A2F-1A25 factory pressure setting: 19–25 bar (A25 pressure stage).

• Pressure adjustment is performed via the hexagon socket set screw—turn clockwise to increase, counterclockwise to decrease.

• Adjust gradually under system operating conditions to achieve the desired pressure value.

3. Hydraulic Fluid Cleanliness

• Recommended fluid cleanliness: ISO 4406 20/18/14 or better.

• Use mineral oil, synthetic hydraulic oil, or lubricating oil meeting specifications.

• Install a return line filter with minimum 25 μm filtration rating.

4. Periodic Maintenance Inspection

• Inspect the valve body for external oil leakage every 2,000 operating hours or at least annually.

• Periodically clean the spool and inspect spring elasticity to ensure long-term reliable operation.

• If pressure setting drift or slow response is observed, first check system fluid cleanliness and verify the sliding piston is not sticking.

• The spring chamber is equipped with an air bleed port—purge air from the spring chamber after installation or maintenance.