Safety valve · Full, instantaneous opening
JAS safety valves
Full opening
Compact full, instantaneous-opening safety valve in brass with a Viton seat. It protects tanks, boilers, and pipes against overpressure and discharges the excess fluid through a piped discharge, without auxiliary power.
- Sizes¼″ to ¾″ inlet
- OpeningFull, instantaneous (A.I.T.)
- Maximum pressurePN16
- Max. temperature180 °C
- MaterialBrass · Viton seat
- Figures310 with lever · 311 sealed
Questions about the set pressure? Call 933 720 888 or email valfonta@valfonta.com.
- Bench-tested under simulated service conditions
- Supplied set to the pressure you specify
- All components numbered
- Material and heat certificates on request
What the JAS is used for
The JAS is a full, instantaneous-opening safety valve: it detects excess pressure in tanks, boilers, or pipes and discharges the excess fluid. When the pressure returns to normal, it closes again. It works with liquids, compressed air, inert gases, and steam, and its piped discharge, with a BSP female thread, lets you route the discharge away.
JAS technical specifications
| Type | Safety valve with full, instantaneous opening (A.I.T.) |
|---|---|
| Figures | 310: with lever · 311: sealed |
| Discharge | Piped |
| Connections | Inlet: BSP male thread · Outlet: BSP female thread |
| Material | Brass · plug with Viton seat |
| Maximum pressure | PN16 |
| Maximum temperature | 180 °C |
| Fluids | Liquids, compressed air, inert gases, and steam |
| Test | On a test bench under simulated service conditions; supplied set to the requested pressure |
| Certificates | Material, heat, and output certificates, if requested in advance |
| Other options | AISI 302/316 stainless steel spring · NPT thread |
Available sizes
| Inlet | Outlet | Figure 310 | Figure 311 |
|---|---|---|---|
| ¼″ | 3/8″ | Yes | Yes |
| 3/8″ | 3/8″ | Yes | Yes |
| ½″ | ¾″ | Yes | Yes |
| ¾″ | ¾″ | Yes | Yes |
JAS technical documentation
Frequently asked questions about the JAS
What is the difference between figure 310 and figure 311?
Figure 310 has a lever that allows the valve to be operated manually. The 311 is the sealed version, with no manual operation.
Is it supplied preset?
Yes. Each valve is bench-tested under simulated service conditions and supplied set to the pressure specified by the customer.
What fluids can it handle?
Liquids, compressed air, inert gases, and steam, up to 180 °C and PN16.
Other Valfonta safety valves
ALPER safety valveAlso full-opening, up to 4″ or DN100, PN25, and 280 °C.
368–371 safety valveProgressive opening, from 3/8″ to 3″ and up to 180 °C.
ALPER atmospheric valvesTank protection against vacuum and overpressure.
Pressure relief valvesS1–S4 and PRV53–55 range, from DN15 to DN150 and set pressure up to 20 barg.
Request a quote for the JAS
Give us your installation details and we will recommend the right size and figure.
- Fluid and temperature
- Set pressure
- Inlet size
- With lever (310) or sealed (311)
You can also call 933 720 888.
