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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.
Hot tapping in progress
PHL founder, Marc Payne
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
New 150mm branch
connection on 200mm medium temp hot water main.
South West Regional Hospital |
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.
 New 32mm branch
connection on 100mm chilled water main. University Research &
Development Unit
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.
Line Stopping
Line
stopping is a method that enables positive temporary isolations to
systems containing a wide range of substances and pipeline materials.
When
used in conjunction with a by-pass, flow to the system can remain
'on-line', thus avoiding costly 'down-time' whilst repairs, relocations
and modifications can take place.
 Hot
tap in operation. South West
Regional Hospital.
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