US Patent 11524186 Low-flow alarm and valve

A low-flow alarm optionally having a variable pressure pre-set threshold, for use with protective suits and hoods is disclosed. In one embodiment, a low-flow valve alarm comprises an adjustable spindle handwheel having a hole, a valve body having an air inlet port, the valve body connected with the adjustable spindle handwheel, a hollow handwheel body joined to the adjustable spindle handwheel, a diaphragm sealing collar joined to a whistlehead retaining body, the whistlehead retaining body having a central bore and joined with a whistlehead, a resilient diaphragm joined with a control spindle disposed within the central bore of the whistlehead retaining body, the control spindle having an air channel, wherein air can travel through the air channel, wherein air flow is adapted to act on the resilient diaphragm, compressing a spring and wherein a low air pressure condition relaxes compression on the spring, producing an audible alarm.