Circle Seal HP524B-2MP Relief Valve
HP500 Series: Adjustable Inline Relief Valves, 150 to 575 psig
Features:
- Very accurate set pressure: valves crack repeatedly at preset pressure with minimal variation
- Zero leakage: up to 95 of cracking pressure
- 100% seat leakage tested: each valve is tested at the factory prior to shipment
- Tamper-proof adjustment: adjustable only from inlet side for safety against tampering; permits precise setting for the most exacting system requirements
- Increased sealing efficiency: as pressure increases, resilient o-ring seal is forced against metal poppet
- Sticking eliminated: poppet head provides metal seat on low pressure side of seal, limiting squeeze on the resilient o-ring; prevents water and dirt from entering valve
- Long, maintenance-free service: parts will not wear out in normal service; overhaul, if necessary, is quickly made by simply replacing the resilient seal
- PED certifications and CE marking available for most models: add “PED” prefix to the valve part number if required

Circle Seal HP524B-2MP Relief Valve Technical Data:
- Description: 1/4″ MNPT X 1/4″ FNPT Inline Relief Valve, Brass/Silicone construction, cracking pressures between 150 to 575 psig
- Maximum Operating Pressure: 575 psig
- Body Material: Brass
- Seal Material: Silicone
- Inlet Connection Size & Type: 1/4″ MNPT
- Outlet Connection Size & Type: 1/4″ FNPT
- Cracking Pressure Range: 150 to 575 psig (REQUIRED SET PRESSURE MUST BE SPECIFIED)
- Flow at Cracking Pressure: 5cc/min
- Reseal Pressure: 90% of cracking pressure
- Leakage (Ascending Pressure): Zero up to 95% of cracking pressure
- Leakage at Reseal Pressure: Zero
- Temperature: -70F to +450F


Dimensional Information:
- Length (“A”): 1.17″
- Hex: 0.625″
Notes:
- Proper filtration is recommended to prevent damage to sealing surfaces.
- Cracking pressure tolerance is ±5%.
- Cracking pressure on initial crack after standing un-actuated for a prolonged period will be higher than the set pressure.
- For PED applications, Brass bodies are limited to a max temp of +100F.
Repair Kit:
- K/HP524B-2MP-L/R
Please contact our Sales Department for assistance in selecting the right products for your application.
Product Catalog: Circle Seal Relief Valves



