INSERTION VALVE AND INSTALLATION METHOD

摘要

A valve assembly for insertion in a line formed by an existing pipe of predetermined outside diameter containing fluid under pressure includes a valve body with a bonnet-supporting flange that defines an access way into the valve body through which an installer can cut and remove a section of the existing pipe. A bonnet with a moveable gate having a width no less than the predetermined outside diameter of the pipe, includes a flange-mating portion that fits into the access way in a fluid-tight fit while defining a gate opening through which the gate moves into the valve body to a closed position in which the gate extends through the gate-receiving gap in the pipe and into fluid-tight engagement of the valve body. Installation is accomplished by (i) assembling the valve body over the existing pipe, (ii) mounting a temporary isolation valve on the bonnet-supporting flange, (iii) cutting and removing a section of the existing pipe through the isolation valve to form the gate-receiving gap in the pipe (iv) installing the bonnet through the isolation valve, and then (v) removing the isolation value up over the bonnet.