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Pressure Relief Valves

281 High Pressure PRI® Relief Valve

This direct-acting valve is ideally suited for high pressure hydraulic applications (up to 5000 psi) where a fast opening safety relief valve is needed to prevent system damage from pressure spikes. Minimum cracking pressures are available from 3000-5900 psid. An integral safety screen is available for added protection.

Key Product Facts
  • High Pressure Relief Valve
  • Diameter:0.281 inches
  • Full Open Lohm Rate:1500 Lohms max
  • Nominal System Pressure:Up to 5000 psi
  • Cracking Pressure Range:3000 to 5900 psi

Product Information

General Performance
Characteristic Specification
Leakage at Minimum Cracking Pressure 10 Drops / Minute Maximum
Leakage at Shutoff 10 Drops / Minute Maximum
Screen Hole Size 0.004 inches Nominal
Nominal System Pressure up to 5000 psi
System Peak Pressure 7500 psi Maximum
Nominal Weight 6.0 grams
Test Fluid MIL-PRF-83282 at 85°F
Materials
PART MATERIAL SPECIFICATION
Body 15-5PH CRES AMS 5659
Pin 15-5PH CRES AMS 5659
Seat 440C CRES AMS 5630
Ball Tungsten Carbide -
Spring Seat 303 CRES QQ-S-763C
Tube 17-4PH CRES AMS 5643
Ball Follower 303 CRES QQ-S-763C
Spring 17-7PH CRES AMS 5678
Screen 304L CRES ASTM A 666
Braze - AMS 4774
Finish: All CRES parts passivated.
Pins are prewaxed. Do not degrease. Do not lubricate.
Flow Curve
Cross Section Views
Dimensional View
Installation Hole Details

Part Numbers & Specifications

This table below contains the part numbers and technical specifications for this product. If you have specific questions, need a quote, or would like to request a handbook or drawing, click the red request button in the column on the far right.

Image Specifications
Flow Curve
Part Numbers & Specifications
Filter Part Numbers
FLOW DIRECTION
PART NUMBER
FLOW DIRECTION
MINIMUM CRACKING PRESSURE (psid) FLOW POINT LOHM RATE FLOW POINT MINIMUM FLOW (gpm) FLOW POINT AT (psid) MINIMUM SHUT-OFF PRESSURE (psid) Request Information
PHFA2815300D Forward 3000 1500 0.9 3600 2850 Request
PHFA2815320D Forward 3200 1500 0.9 3850 3000 Request
PHFA2815340D Forward 3400 1500 0.95 4050 3200 Request
PHFA2815420D Forward 4200 1500 1 4750 3700 Request
PHFA2815450D Forward 4500 1500 1 5100 4000 Request
PHFA2815470D Forward 4700 1500 1.1 5300 4200 Request
PHFA2815520D Forward 5200 1500 1.1 5800 4550 Request
PHFA2815570D Forward 5700 1500 1.2 6350 5000 Request
PHFA2815590D Forward 5900 1500 1.2 6600 5200 Request
PHRA2815300D Reverse 3000 1500 0.9 3600 2850 Request
PHRA2815320D Reverse 3200 1500 0.9 3850 3000 Request
PHRA2815340D Reverse 3400 1500 0.95 4050 3200 Request
PHRA2815420D Reverse 4200 1500 1 4750 3700 Request
PHRA2815450D Reverse 4500 1500 1 5100 4000 Request
PHRA2815470D Reverse 4700 1500 1.1 5300 4200 Request
PHRA2815520D Reverse 5200 1500 1.1 5800 4550 Request
PHRA2815570D Reverse 5700 1500 1.2 6350 5000 Request
PHRA2815590D Reverse 5900 1500 1.2 6600 5200 Request
Clear Filters
Performance on MIL-PRF-83282 at 85°F

Installation & Accessories

Replacement Parts & Accessories
PART NUMBER DESCRIPTION
CUTA2810114C Installation / Extraction Tool Set
SHBA2810003A Replacement Pin

CAD Envelopes

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From plugs to solenoid valves, there’s a vast array of products that The Lee Company can offer. If you’d like to discuss the best solution for your specific application or to learn more about our capabilities, use-cases, or quality standards, contact your local Lee sales engineer.