Inflatable bulkhead useful in underground pipe refurbishment

Abstract

A method for refurbishing an existing host pipe, in which an in-situ longitudinal cut is made in the interior wall of a subterranean host pipe. An expansion tool is moved along a path inside the host pipe, stopping at one or more stations on the way. At each station, responsive to isolated outward radial force from the expansion tool, the interior diameter of the host pipe is increased via separation of the longitudinal cut. A new rigid liner pipe is inserted inside the expanded host pipe to operationally replace the host pipe. In some embodiments, grout is deployed in the annular space between liner pipe and host pipe. Expansion of the host pipe via separation of the longitudinal cut optimizes the refurbishment job and enables the original host pipe, as expanded, to contribute structurally to the refurbished pipe system.

I claim: 
     
         1 . An inflatable bulkhead, comprising:
 an inflatable ring, the inflatable ring including a substantially continuous wall, the wall retaining an inflatable void;   an inflation valve deployed in the wall and sealed into the wall, wherein the inflation valve enables selective inflation and deflation of the inflatable ring; and   at least one grout fitting, each grout fitting inserted through the inflatable ring, wherein each grout fitting (1) enters the inflatable ring through a corresponding grout fitting wall entry point, (2) passes through the void and (3) exits the inflatable ring through a corresponding grout fitting wall exit point;   wherein further each gout fitting is sealed into the wall at its corresponding wall entry point and at its corresponding wall exit point; and   wherein further each grout fitting seals grout from the void while enabling grout to pass through the inflatable ring.   
     
     
         2 . The inflatable bulkhead of  claim 1 , in which the wall is made from a material selected from the group consisting of (a) rubber, and (b) a rubber composite. 
     
     
         3 . The inflatable bulkhead of  claim 1 , in which at least one grout fitting is made from a material selected from the group consisting of (a) brass, and (b) stainless steel. 
     
     
         4 . The inflatable bulkhead of  claim 1 , in which each grout fitting has a grout connector on one end thereof, the grout connector configured to connect with a liquid grout hose. 
     
     
         5 . The inflatable bulkhead of  claim 1 , in which each grout fitting further includes a grout fitting plug for selectively sealing or unsealing the grout fitting from grout flow therethrough. 
     
     
         6 . An inflatable bulkhead, comprising:
 an inflatable ring, the inflatable ring including a substantially continuous wall, the wall retaining an inflatable void;   an inflation valve deployed in the all and sealed into the wall, wherein the inflation valve enables selective inflation and deflation of the inflatable ring; and   three grout fittings, each grout fitting inserted through the inflatable ring, wherein each grout fitting (1) enters the inflatable ring, through a corresponding grout fitting wall entry point, (2) passes through the void and (3) exits the inflatable ring through a corresponding grout fitting wall exit point;   wherein further each grout fitting is sealed into the wall at its corresponding wall entry point and at its corresponding wall exit point; and   wherein further each grout fitting seals grout from the void while enabling grout to pass through the inflatable ring.   
     
     
         7 . The inflatable bulkhead of  claim 6 , in which the wall is made from a material selected from the group consisting of (a) rubber, and (b) a rubber composite. 
     
     
         8 . The inflatable bulkhead of  claim 6 , in which the grout fittings are made from a material selected from the group consisting of (a) brass, and (b) stainless steel. 
     
     
         9 . The inflatable bulkhead of  claim 6 , in which each grout fitting has a grout connector on one end thereof, the grout connector configured to connect with a liquid grout hose. 
     
     
         10 . The inflatable bulkhead of  claim 6 , in which each grout fitting further includes a grout fitting plug for selectively sealing or unsealing the grout fitting from grout flow therethrough. 
     
     
         11 . The inflatable bulkhead of  claim 6 , in which the grout fittings are spaced equidistantly around the inflatable ring.