The 32-436 suction relief valve is highly reliable and long lasting. Once set at the factory, it requires no further maintenance or adjustments. A stainless steel spring and a robust gasket assure that the valve exhibits no fluctuations or sluggishness during operation, and that it closes tightly. The valve is preset at a flow of 2.8 C.F.M to maintain a vacuum of 4.8 or 5.4 in. of mercury. Operating vacuum range is nominally from 2.8 to 6.5 in. of mercury at flows from 2.8 to 6.5 C.F.M.