Definition - What does Host Pipe mean?
A host pipe is the tube, or pipe, which carries the product being transported. It can be made of steel, concrete, clay, plastic, ductile iron or other materials. The host pipe can be bored directly under ground or it can be installed in a casing. The ultimate goal of any trenchless process is to install or repair a host pipe in place to carry product.
Trenchlesspedia explains Host Pipe
A host pipe may be installed inside a casing as part of the trenchless procedure, especially when installed under highways or other heavily trafficked areas where surface weight fluctuations are a consideration. When host pipe is installed in a casing, the gap between the casing and host pipe is sealed with grout. Host pipes can be replaced by sliplining if the original host pipe is fragmented. In a sliplining process, a smaller "carrier pipe" is installed into a larger "host pipe" and the space between the two pipes is sealed with grout.