an air inversion and steam cure apparatus for installing a flexible resin impregnated cured in place liner in an existing conduit is provided . the apparatus has a low friction seal between a moving liner and the stationary apparatus gland . the gland is operated and adjusted by displaceable members that move substantially perpendicular to the liner being inverted to engage the moving liner as it passes through the gland . no part of the gland extends into the chamber so that once a pre - shaped gland is adjusted , the pressure on the moving liner is not increased . as the liner reaches the distal end , it enters a sample and porting pipe with an exhaust pipe gland and exhaust pipe and is pierced by a rigid porting tool . steam is then introduced into the liner to cure the resin and is exhausted through an exhaust hose connected to the porting tool . after cure , steam is replaced with air to cool the liner and the ends are cut to restore service through the existing conduit .