Hot Tapping

On Site activity with plant pressure equipment in line

Hot Tapping is a technique widely used to create new branches from existing pipeline systems.

It consists of welding or more rarely bolting, a fitting on the affected manifold, installing a full bore valve (gate, ball or special) and then drilling a hole with a drill-cutter equipped with a sealing system to prevent the fluid from escaping.

After drilling the hole and recovering the bottom, the valve is closed, the machine is removed, leaving the new unit ready for use (eg insertion of new tools, connections to new systems, drains and vents, etc.).

Applications of line plugging

It consists in making a preliminary access hole to the line using the hot tapping technique and then inserting a shutter system inside the line.

After making the hole, generally of the same diameter as the manifold or slightly smaller, the shutter system is inserted, which for modest pressures (up to 1 bar) can be a balloon, while in most cases it is a plug with different geometries and types.

In cases where it is necessary to repair a pipe that cannot be excluded from the service, for example because the shut-off valves do not exist or are not functioning upstream, and for which it is possible to interrupt the downstream users, it can be realized a single line stop.

Thus, the terminal section of a plant or line is temporarily excluded for the time necessary for repair.

At the end of the repair, the machine is removed and the fitting secured.

In cases where, on the other hand, it has been decided to carry out a repair with the system in operation, but it is not possible to interrupt the downstream utilities, a temporary by-pass is created.

After carrying out two hot tappings, one upstream and one downstream of the line section to be repaired, the by-pass is installed and put into operation.