Scroll down below to click on a valve size for pricing and then click on the spring range to see which options are available for that size. After selecting your options you may then print out a price, e-mail it (without having to contact the factory), and then when you are ready, proceed to order.
When ordering don't forget to state your desired relief set pressure if you expect the valve to relieve at only one pressure. There is no extra charge for this. This pressure will be engraved on the valve body.  If the set pressure is not specified, the valve will be set at or below the stated spring range as selected for the order and no set pressure will be engraved. 

• Body: Hastelloy, Monel, Titanium, Alloy20
• Piston: Hastelloy, Monel, Titanium, Alloy20
• Spring: Hastelloy, Monel, Titanium, Alloy20
• Lock nut: Hastelloy, Monel, Titanium, Alloy20
• Elastomeric seal: Bubble-tight seal is achieved with soft elastomers such as Buna, Viton, and EPDM and Kalrez, but not with the harder seal material, Teflon (PTFE) .
• Tamper-proof construction-This valve is not externally adjustable & requires removal of the valve to change the pressure setting.
• Adjustable pressure-setting valve can be factory-set or adjusted in the field. Spare springs can be changed in the field to achieve a different pressure range.

This is a poppet (piston) and spring type relief valve where the spring constantly opposes the pressure acting against the piston which seals off the inlet port. The desired set pressure or relief is achieved by compressing the spring until the spring force is adequate to balance the pressure force acting against the poppet. The valve can be ordered factory-set for a specific relief pressure, or can be adjusted in the field. Setting the correct relief pressure in the field may require several tries, and requires measurement with a pressure gauge to verify. In order to make the pressure adjustment, the valve needs to be unscrewed from its mounting position with pressure removed from the line. Increasing the spring pressure increases the relief pressure and visa versa. A small nut driver and screwdriver may be used to make pressure adjustments for the low pressure springs. Where frequent pressure adjustments are anticipated, a special adjusting tool can be purchased from Straval which can be used for the 1/4" RVi05 size only and also for the 1/8" & 1/4"Rva05 models. This tool can be purchased from Straval, Part Number T234 (Click on link to order).

When reinstalling the 1/4"Npt model do not exceed 10 ft-lbs on the male pipe thread end as minor distortions to the body may occur if substantially exceeded.

The larger sizes can be more easily adjusted with more conventional tools. However, ordering the valve to the correct set pressure would minimize or eliminate the need for making pressure adjustments in the field.