摘要 |
<p>A fluid vent (26) for venting fluid from the annulus between the inner surface of a rigid conduit (20) and the outer surface of a conduit liner (10). The fluid vent (26) consists of a length of rigid conduit (34) containing a multiplicity of apertures (32) extending through the wall of the conduit and arranged in an annular pattern around the circumference of conduit (34). The fluid vent (26) further comprises means defining a closed annular volume (36) extending around the exterior circumference of the conduit (34) and interconnecting the outer ends of the apertures (32) with at least one fluid outlet passage (40) located on the exterior of the conduit (34) and communicating with said annular volume (36). The fluid vent can be used to expel water or other liquids from the annular space when retro-fitting a liner to a conduit, venting gas which has permeated through the lining into the annulus, or for assisting in the movement of fluid through the annulus.</p> |