Circle Seal M5132T-ASME Relief Valve
M5100 Series: ASME Safety Relief Valves, 20 to 1200 psig
Features:
- Zero leakage: from 0 psi up to 70% of the marked set pressure
- Manual Override: offered with ring or lift handle
- PED certifications and CE marking available: add “PED” prefix to the valve part number if required
Terminology for ASME Safety Relief Valves:
- Safety Relief Valves: An automatic pressure relieving device actuated by the static pressure upstream of the valve, which opens in proportion to the increase over the opening pressure.
- Start-to-Leak Pressure: The pressure at the valve inlet where the relieved fluid is first detected (on the downstream side of the seat) before normal relieving action takes place.
- Opening Pressure (Set Pressure): The valve inlet pop point pressure at which there is a measurable lift or discharge becomes continuous as determined by seeing, hearing or feeling. In the pop type of safety valve, it is the inlet pressure at which the valve opens, allowing a larger amount of fluid as compared with corresponding valve movements at higher or lower pressures.
- Relieving Pressure: (Opening pressure plus overpressure) The pressure measured at the valve inlet at which the relieving capacity is determined.
- Closing Pressure: (Reseat pressure) The pressure measured at the valve inlet, at which the valve closes, flow is substantially shut off, and there is no measurable lift.
- Seal-off Pressure: The pressure (measured at the valve inlet) after closing at which no further gas is detected at the downstream side of the seat.
- Operating Pressure: The actual pressure at which a vessel is maintained in normal operation.
- Accumulation: Pressure buildup or overpressure beyond the set pressure of a safety relief valve, at which capacity flow is rated. Capacities are usually based on 10% accumulation.
Circle Seal M5132T-ASME Relief Valve Technical Data:
- Description: ASME Relief Valve, 1/8″ to 1″ MNPT connections, constructed in 303SS with Viton seal, cracking pressures from 20 to 1200 psig (depending on size)
- Body Material: 303SS
- Seal Material: Viton
- Set Pressure (REQUIRED SET PRESSURE MUST BE SPECIFIED):
- 1/8″, 3/4″, 1″ sizes: 20 to 1200 psig
- 1/4″, 3/8″, 1/2″ sizes: 50 to 1200 psig
- Handle Type:
- Ring Handle:
- 1/8″, 1/4″, 3/8″ sizes: all set pressures
- 1/2″, 3/4″, 1″ sizes: all set pressures up to 450 psig
- Lift Handle:
- 1/2″, 3/4″, 1″ sizes: all set pressures above 450 psig
- Ring Handle:
- Temperature: -20F to +400F
Flow Curve:


Notes:
- The complete part number MUST INCLUDE the set pressure in psi. The ASME code requires that valves be set at a “pop point”. The ASME code refers to this as the set pressure. This point is higher than the traditional Circle Seal definition of cracking pressure.
- After a prolonged period of storage with no system pressure, these relief valves will exhibit an apparent high set pressure on first “pop”; therefore, in receiving inspection tests the true set pressure should be determined after the first “pop”.
- These valves are tested in accordance with procedures in Paragraph UG 131, Section VIII of the ASME Unified Pressure Vessel Code.
- Proper filtration is recommended to prevent damage to sealing surfaces.
- It is solely the responsibility of the system designer and user to select products suitable for their specific application requirements and to ensure proper installation, operation and maintenance of these products. Material compatibility, product ratings and application details should be considered in the selection. Improper selection or use of these products can cause personal injury or property damage.
Please contact our Sales Department for assistance in selecting the right products for your application.
Product Catalog: Circle Seal M5100-ASME Series Relief Valves


