Patent ID: 6263896
Filing Date: 2001-07-24
Classification: F16K,F16L,Y10T

Abstract:
A pressure flow stop for selectively blocking flow of fluid through a conduit by using pressurized air to facilitate replacing a fluid shutoff valve on the conduit and attaching a water meter to the fluid shutoff valve, said pressure flow stop comprising a stem housing for removable attachment to the fluid shutoff valve; an elongated stem for extension through said stem housing and the fluid shutoff valve, said stem comprising a stem valve for receiving the pressurized air and a housing shaft provided in pneumatic communication with said stem valve for receiving the pressurized air from said stem valve; a backup stem provided in pneumatic communication with said housing shaft for receiving the pressurized air from said housing shaft; an inflation stem removably pneumatically coupled to said backup stem for receiving the pressurized air from said backup stem; an air non-return valve provided on said inflation stem, said air non-return valve disposed in an open configuration when said inflation stem is connected to said backup stem to maintain pneumatic communication between said inflation stem and said backup stem, and said air non-return valve disposed in a closed, air-sealing cofiguration when said inflation stem is disconnected from said backup stem; and a balloon provided in pneumatic communication with said inflation stem for location in the conduit and receiving the pressurized air from said inflation stem, said balloon and said inflation stem inserted through the fluid shutoff valve and into the conduit by applying pressure against said housing shaft to advance said housing shaft in said stem housing, whereby the pressurized air flows through said stem and into said balloon and said balloon inflates on said inflation stem and substantially obstructs and blocks fluid flow through the conduit, responsive to introducing the pressurized air into said stem valve; and the fluid shutoff valve is replaced on the conduit by removing said stem housing from the fluid shutoff valve; uncoupling said backup stem from said inflation stem with said inflation stem extending through the fluid shutoff valve and said balloon obstructing the conduit, whereby said air non-return valve closes to maintain the pressurized air in said balloon; disconnecting the fluid shutoff valve from the conduit and sliding the fluid shutoff valve over said inflation stem to remove the fluid shutoff valve from said inflation stem; sliding a replacement fluid shutoff valve over said inflation stem and connecting the replacement fluid shutoff valve to the conduit, whereby said inflation stem extends through the replacement fluid shutoff valve; re-coupling said backup stem to said inflation stem, whereby said air non-return valve opens to re-establish pneumatic communication between said inflation stem and said backup stem; connecting said stem housing to the replacement fluid shutoff valve with said backup stem and said housing shaft extending through said stem housing; deflating said balloon and removing the pressurized air from said stem by operation of said stem valve; removing said balloon from the conduit by withdrawing said stem from said replacement fluid shutoff valve; closing the replacement shutoff valve; removing said stem housing from the replacement fluid shutoff valve; attaching the water meter to the replacement water shutoff valve; and opening the replacement water shutoff valve to establish flow of water from the conduit, through the replacement water shutoff valve and to the water meter.