Vacuum limiting, regulating device

In a device for limiting the applied vacuum in a fluid suctioning system, the combination comprising

• (a) a chamber having an inlet at which a suction level or levels V.sub.x is or are to be maintained, and an outlet to which vacuum level V.sub.2 is applied, wherein V.sub.x <V.sub.2, fluid being sucked through said chamber via said inlet and outlet,
• (b) an annular seat in said chamber, the chamber containing an upstream flow zone R.sub.1 between said inlet and said seat, and a downstream flow zone R.sub.2 between said seat and said outlet, the seat facing longitudinally,
• (c) and a diaphragm at the upstream side of the seat and extending crosswise thereof and crosswise of at least a portion of said zone R.sub.1, the diaphragm having a top wall carried for longitudinal movement toward the seat when the vacuum level in R.sub.1 rises to a predetermined level, to reduce or block fluid flow through the chamber, the diaphragm top wall movable away from the seat when the vacuum level in R.sub.1 falls below a predetermined level,
• (d) the chamber having an outer wall that faces laterally and extends about said seat,
• (e) said diaphragm consisting of elastomeric material and having a peripheral skirt which extends in a position proximate said outer wall that faces laterally, the diaphragm skirt retained in said position for positioning said diaphragm top wall for said movement toward and away from the seat.
• (f) the diaphragm top wall substantially everywhere deflected toward the seat by the outer wall when the diaphragm top wall extends furthest from the seat.