Hot Tapping / Wet Tap
Hot tapping service is a field machining process which enables tie-ins to on-stream pipe, tanks, or any pressurized gas or liquid containing vessel without shutting down service and without release or loss of product. Hot tapping also permit the insertion under pressure of sensing or metering devices into the flow stream, installation of permanent or temporary bypass piping, and hot taps are the preparatory stage for line plugging.
Topaz is currently equipped for hot tapping service:
½" thru 48" in tap size
1480 PSIG Maximum working pressure @ 100°F.
700°F. Maximum temperature @ 700 PSIG
Information we require for hot tapping service:
Size of valve through which hot tapping service will be done
Is the valve threaded or flanged? ANSI rating? (150#, 300#, 600#, etc.)
Nominal size, wall thickness, and material of the line to be tapped.
Product in the line to be tapped.
Operating pressure and temperature.
Overall length of tapping nozzle and valve. Before welding request our dimensional brochure, view the link below or confer with Topaz.
The customer is asked to provide:
Craft labor and lifting equipment to position Topaz machines.
100 CFM air @ 120 PSIG to power Topaz pneumatic machines. If compressed air is not available, Topaz can provide hydraulic or electric powered machines (electric available for 14” and smaller hot taps only).
Necessary studs, nuts and gaskets to attach Topaz machines to the hot tapping valves.
Scaffolding, if required.
Angle hot tapping:
This procedure involves any hot tap where the tapping nozzle is not perpendicular to the surface being tapped. Before welding, contact Topaz to discuss degree of angle and the possible need for a centering device to stabilize the pilot drill. We are currently equipped to perform angle hot taps in sizes 1" through 24", as much as 45° off perpendicular, and into the heel or backside of short or long radius ells.
Hot Tapping blind flanges and heavy wall vessels:
Hot tapping thick wall pipe, vessels and blind flanges is possible, provided special issues are addressed in the design of the tapping branch connection. Please consult Topaz prior to welding to discuss these considerations.
Hot Tapping materials other than carbon steel:
In addition to carbon steel, we commonly hot tap cement lined pipe, transite, cast iron, stainless steel and other alloys, plastic and fiberglass. Although we hot tap these materials frequently, additional information such as the thickness and composition of linings, hardness of alloys, or type of fitting and valve through which we will be operating may be needed to insure that proper equipment is provided for your job.
Hot Tapping materials that can not be welded:
If hot tapping or plugging a line is necessary that cannot be welded on, such as cast iron, transite, or even carbon steel in an area where welding is not permitted, a mechanical bolt-on tapping or plugging fitting can be provided. Topaz offers a variety of mechanical fittings types in order to provide the right fitting at the right price and delivery for your project. If a standard fitting configuration doesn’t suit your application, custom fittings can be fabricated that will meet your needs.
Topaz has the capability to install thermowells in a system while it remains in service and under pressure. When informed of your thermowell specifications, we can supply a standard thermowell fitting from stock, or design and fabricate something unique to your application. Pertinent thermowell specifications include male and female thread type and size, shank diameter, and overall length. Once the fitting is welded in place, Topaz will provide a temporary valve through which we hot tap the vessel wall, and then set the thermowell. After the thermowell is set, line pressure is sealed within the fitting and the temporary valve is removed, permitting an unobstructed attachment of instrumentation. In addition to thermowells, various other types of metering devices can be installed under pressure using similar techniques and appropriate fittings.