Circle Seal M5120T-4M Relief Valve
5100 Series: Adjustable Popoff Relief Valves with Manual Override, 20 to 2400 psig
Features:
- Zero leakage: to 95-98% of cracking pressure
- Positive reseat: reseals at high percentage of the cracking pressure
- Accurate set pressure: valves can be pre-set to required cracking pressure
- Adjustable: interchangeable springs permit change of crack pressure range; tamper-proof adjustment inside of valve
- Excellent flow characteristics: lift ring poppet design allows high flow rates with minimum amount of pressure rise
- No chatter: chatter eliminated through use of friction damping device; damping bars prevent poppet from over-travel at initial cracking thrust; damping load is proportional to spring load
- Minimal maintenance: fluid is not throttled across the seal, which, combined with soft seat and poppet design, prevents seat and seal erosion
- Versatile: vent-to-atmosphere or inline connections; various materials for both body and seals; sizes ranging from 1/8″ to 1-1/4″
- PED certifications and CE marking available for most models: add “PED” prefix to the valve part number if required
Circle Seal M5120T-4M Relief Valve Technical Data:
- Description: 1/2″ MNPT Popoff with Manual Override Relief Valve, 303SS/PTFE construction, cracking pressures between 20 to 2400 psig
- Configuration: Popoff with Manual Override
- Maximum Operating Pressure: 2400 psig
- Body Material: 303SS
- Seal Material: PTFE
- Inlet Connection Size & Type: 1/2″ MNPT
- Outlet Connection Size & Type: NONE: DISCHARGE-TO-ATMOSPHERE
- Cracking Pressure Range: 20 to 2400 psig (REQUIRED SET PRESSURE MUST BE SPECIFIED)
- Flow at Cracking Pressure: 0.02 SCFM
- Reseal Pressure:
- Cracking pressures less than 450 psig: 52% to 90% of cracking pressure
- Cracking pressures greater than 450 psig: 90% of cracking pressure
- Leakage at Reseal Pressure (Ascending Pressure): Zero up to reseal pressure, then 10 cc/min between reseal and cracking pressure
- Leakage at Reseal Pressure (Descending Pressure): Zero at reseal pressure, except with cracking pressure below 451 psig, then 1 cc/min maximum
- Temperature: -100F to +400F
Cracking / Reseal Pressure Graphs:
Dimensional Information:
- Handle Type: Ring (for cracking pressures between 20 and 450 psig) OR Lift (for cracking pressures between 451 and 2400 psig)
- Length (“E”): 3.86″ (for cracking pressures between 20 and 450 psig)
- Length (“M”): 5.51″ (for cracking pressures between 451 and 2400 psig)
- Diameter (“B”): 1.25″ (for all cracking pressures)
- Hex (“H”): 1.25″ (for all cracking pressures)
Notes:
- Proper filtration is recommended to prevent damage to sealing surfaces.
- Cracking pressure tolerance is ±5% (±20% if set pressure is below 20 psig).
- Cracking pressure on initial crack after standing un-actuated for a prolonged period will be higher than the set pressure.
- The reseal point is the point at which the valve seals absolutely tight so that there is no leakage detectable by normal means of measurement. The point at which the valve closes, cutting off virtually all flow, is called the reseat point. The reseat point is substantially above the reseal.
Adjustment:
The Circle Seal 5100-series relief valve is adjustable to ±15% of its nominal cracking pressure as follows:
- Remove discharge line (for inline configuration).
- “Break” the body joint by wrenching the hexes. DO NOT USE PIPE WRENCH.
- Insert proper size hex wrench into the outlet end and turn clockwise to increase the cracking pressure or counter-clockwise to decrease the cracking pressure.
- After adjustment to the desired cracking pressure, hold the hex wrench stationary relative to the inlet end and turn the body to tighten the joint.
- Test adjusted unit for cracking pressure.
Repair Kit(s):
- K/M5120T-4M-A/U (for all cracking pressures between 20 and 2400 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 5100-Series Relief Valves
