Relief valve

Abstract

A relief valve having a crenelated exhaust ring surrounding the poppet. The crenelated exhaust ring comprises a series of alternating crenels and merlons which together define an increasing cross-sectional exhaust area circumferentially about the poppet during cracking (i.e., once the pressure in the inflatable device exceeds the cracking pressure) as the poppet rises in the relief valve in response to increased pressures and, conversely, a decreasing cross-sectional exhaust area about the poppet during closing as the poppet lowers to its re-seated, sealed position. The design of the crenels in the form of a larger upper cross-sectional area to a smaller lower cross-sectional opening, advantageously achieves a reseating pressure that is substantially equal to or slightly less than the cracking pressure while minimizing possible oscillations during re-seating of the poppet. The crenelated exhaust ring surrounding the poppet advantageously results in a relief valve having a higher flow rate at a given back pressure than would be achieved without the crenelated exhaust ring surrounding the poppet.