Hot tapping, or under- pressure drilling,  is a method of making a connection to existing pipelines or tanks while that existing system is under pressure.  

This method employs a drilling or tapping machine, a full-ported valve and a pressure-containing fitting to the existing pressurised system.  The end result a new branch connection abstracted from the original pipe while the line is still operational.

The overall process is completed without any leakage or interruption to the flow of liquid. It is possible to perform a hot tap on pipes from 1″ to 48″ with pressure ratings up to 1480 psi and temperatures up to 700 degrees Fahrenheit.

The types of pipes that this method can be applied to is almost unlimited:

• Cast iron
• Ductile iron
• Non ferrous metal
• Mild steel
• Plastic
• Reinforced concrete

A typical application includes the use of a fitting designed to contain system pressure, a valve, used to control the new branch connection, weld or clamp, and a drilling machine to make the hot tap. The drilling machine generally consists of a mechanically driven telescoping boring bar which advances a cutting tool.

A necessary element in most hot-tap connections is the full-ported valve, which can become a control valve for the new connection, and allows the drilling machine to be removed after the cutting operation. Gate valves and other full-ported valves with flanges and screwed connections; typically include 150lb through 900lb ANSI ratings.

PHL purchases its machinery from leading international suppliers of hop tap equipment and therefore has access to the latest developments in this fast-moving engineering process. PHL is therefore able to put a wider range of solutions together, testing the boundaries, whilst maintaining good practice and adhering to our stringent safety codes.