Circle Seal D559N-2M-ASME ASME Relief Valve
D500 Series ASME: Popoff Relief Valves 15 to 150 psig
Features:
- Zero leakage: from 0 psi up to 70% of the marked set pressure
- Deflector cap: diverts high pressure blasts from personnel and instruments and serves as a rain and dust shield
- 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. Note: A safety relief valve is not considered to open when it is simmering at a pressure just below the popping point even though the simmering may be audible. This set pressure distinguishes our ASME relief valves from our standard relief valves whose cracking pressure indicates initial flow.
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 D559N-2M-ASME Relief Valve Technical Data:
- Description: 1/4″ MNPT Popoff ASME Relief Valve, Naval Brass/Buna-N construction, cracking pressures between 15 to 150 psig
- Configuration: Popoff with deflector cap
- Maximum Operating Pressure: 150 psig
- Body Material: Naval Brass
- Seal Material: Buna-N
- Inlet Connection Size & Type: 1/4″ MNPT
- Outlet Connection Size & Type: NONE: DISCHARGE-TO-ATMOSPHERE
- Set Pressure Range: 15 to 150 psig (REQUIRED SET PRESSURE MUST BE SPECIFIED)
- Temperature: -20F to +250F
Flow Curve:
Dimensional Information:
- Length (“A”): 1.1875″
- Hex (“B”): 0.625″
- Diameter (“C”): 0.90″
Recommended Installation:
- 1. Before installing a new safety relief valve, we recommend that a pipe tap be used to assure clean-cut and uniform threads in the vessel opening and to allow for normal hand engagement followed by a half to one turn by wrench.
2. Avoid over-tightening as this can distort the valve seat.
3. Avoid excess “popping” of the valve. Safety relief valves should only be operated often enough to assure they are in good working order.
4. Apply only a moderate amount of pipe compound or tape to the threads, leaving the first thread clean parts.
5. Don’t oversize the valve, as this may cause chatter resulting in rapid wear of the moving parts.
6. Avoid wire, cable, or chain pulls for attachments to levers that do not allow a vertical pull. The weight of these devices should not be applied to the safety relief valve.
7. Avoid having the operation pressure too near the valve set pressure. A minimum differential of 10% is recommended.
Please contact our Sales Department for assistance in selecting the right products for your application.
Product Catalog: Circle Seal Relief Valves
