NVE RIV 1-1/2″ Brass Vacuum Relief Valve

The functional features of the valve have been specially studied to guarantee the complete safety of the product:
a) A mechanical stop (12) regulates the valve opening in the position of maximum discharge.
b) In case of accidental unscrewing of the nut that adjusts the spring because of the vibrations, a second stop (11) blocks mechanically the unscrewing and guarantees anyway a min. calibration of about -0,3 bar (-4 Psi). Furthermore it prevents the nuts from unscrewing completely and falling into the equipments on which the valve is installed.
c) For safety reasons, the diameter of the obturator (3) is larger than the discharge orifice, so that, in case of an accidental breaking of the stem, the obturator can’t fall into the equipments, on which the valve is installed.
The valve can be easily adjusted to the desired pressure, after which the cap can be sealed tamper-proof through two practical drilled tongues.