The relief pressures on a series of relief valves are easily identified by the color of the valve. Offered in 1/8 and 1/4 male NPT and 1/8 female thread, the valve housing is molded of Polyvinylidene Flouride (PVDF), an extremely stable and pure commercial resin. Special end sizes are also available. The internal relief material is nylon with a Buna-N seal. Also available: polypropylene or PVDF bodies and optional Viton seals.