Designed for use as primary relief valves in aboveground and underground ASME tanks, bulk installations in factories, and platform tanks. The 3131 series can also be used as a primary or secondary relief valve in DOT tanks or as a hydrostatic relief valve. All actuators of such safety valves are located outside the tank connection, therefore the valves must be protected from physical damage.
| Элемент | 3131, 3132, 3133, 3135 | AA3126 AA3130 | AA3135 | A3149 |
| Корпус: | Латунь | Алюминиевый прокат | Верх - холоднокатаная сталь; низ - вязкая сталь | |
| Втулка: | Нет | Нержавеющая сталь | ||
| Направляющая: | Латунь | Алюминий | Нержавеющая сталь | |
| Пружина: | некорродир. сталь | Легир. сталь | ||
| Седельный диск: | эластичная полимерная композиция | |||