Circle Seal 520B-4M Relief Valve
500 Series: Adjustable Popoff & Inline Relief Valves, 0.5 to 150 psig
Features:
- Popoff, Popoff with Deflector Cap, or Inline configurations
- Adjustable, factory preset cracking pressure
- Zero leakage
- Accurate set pressure
- Wide range of cracking pressure
- Tamper-proof adjustment
- 100% seat leakage tested
- PED certifications and CE marking available for most models (add “PED” prefix to the valve part number if required)
Applications:
- System overpressure protection
- Storage tanks
- Freon recovery systems
- Medical equipment
- Refrigeration and heating equipment
- Measuring & dispensing pumps
- Communications equipment
- Process control instruments
- R&D pilot plants
- Vacuum pump safety
Circle Seal 520B-4M Relief Valve Technical Data:
- Description: 1/2″ MNPT Popoff Relief Valve, Brass/PTFE construction, cracking pressures between 0.5 to 150 psig
- Configuration: Popoff
- Pressure Rating: 150 psig
- Body Material: Brass
- Seal Material: PTFE
- Inlet Connection Size & Type: 1/2″ MNPT
- Cracking Pressure: 0.5 to 150 psig (REQUIRED SET PRESSURE MUST BE SPECIFIED)
- Flow at Cracking Pressure: 0.02 SCFM
- Leakage, Ascending Pressure: Cracking pressures up to 2.4 psi: 4cc/min at 0 to 50% of cracking pressure; Cracking pressures 2.5 psi and higher: 1 cc/min at 0 to reseat pressure, 10cc/min from reseat to 90% of cracking pressure
- Leakage at Reseat Pressure: 1cc/min for cracking pressures 2.5 psi and higher
- Temperature: -100F to +400F
Cracking / Reseal Pressure Graphs:
Air Flow Rate Table:
Dimensional Information:
- Length (“L1″): 1.74”
- Hex (across flats): 1″
Notes:
- Proper filtration is recommended to prevent damage to sealing surfaces.
- Cracking pressure tolerance is ±5% (may be greater than ±5% if set pressure is ≤ 1 psi); cracking pressure on initial crack may be higher than cracking pressure tolerance due to inherent characteristics of seals.
Repair Kit(s):
- K/520B-4M-A/G (for all cracking pressures between 0.5 and 150 psig)
Please contact our Sales Department for assistance in selecting the right products for your application.
Product Catalog: Circle Seal Relief Valves
Service Information Sheet: Circle Seal 500-Series Relief Valves
