Patent ID: 7111638

Claim:
An excess flow shutoff comprising: a body having a flow path including an inlet passage, a enlarged central cavity, and an outlet extending from said cavity; a shutoff seat in said flow path between said inlet passage and said outlet; a shutoff sleeve mounted in said body for movement between an upstream open position and a downstream closed position and having an upstream stem portion slideably received in said inlet passage with a clearance defining a damper flow path; said shutoff sleeve having a downstream closure portion engageable with said shutoff seat to block flow through said flow path in said closed position; a spring in said cavity biasing said shutoff sleeve toward said open position; a flow metering passage through said shutoff sleeve for developing a flow responsive pressure drop urging said shutoff sleeve against the biasing force of said spring from said open position to said closed position in response to excess liquid flow; a resilient damper bladder; a variable volume damper chamber defined in part by said resilient damper bladder; and a restricted passage extending from said damper flow path to said damper chamber for increasing the pressure in said damper chamber in response to increasing flow through said flow path.