Abstract: A multi-purpose pipe and seal/alignment device is provided for sealing pipe ends against internal or external pressure while protecting the pipe end preparation from damage to facilitate a permanent pipe joining process at a remote location in an adverse environment.

Abstract: An electromagnetic system is provided for accurately sensing and remotely controlling a tool-to-workpiece spatial relationship. A typical application of the system may include a saw being sensor controlled through the process of removing a reinforced concrete covering from and about an underwater pipe or other metallic object that must be protected.

Abstract: A multi-purpose pipe end seal/alignment device is provided for sealing pipe ends against internal or external pressure while protecting the pipe end preparation from damage to facilitate a permanent pipe joining process at a remote location in an adverse environment.

Abstract: A check valve adapted for mounting between the faces of a pair of pipe flanges having flow passages of equal diameters and joined by bolts circumferentially spaced about the flanges. A valve body having a cylindrical flow passage therethrough is formed with end sections, each of which has a surface adapted for sealing engagement with a face of the pipe flanges, and a clapper being mounted for pivoting between a closed position completely blocking the valve body flow passage and an open position withdrawn from the flow passage but within the valve body.