Explosively welded plugs are installed inside the tube or tubesheet,
thus liminating tubesheet weld buildup. These plugs are extremely
efficient and have proven to be the most economical way to repair all
feedwater heater tube leaks.
Advantages of Explosively Welded Tube
Plugging
Superior
Joint Integrity
Joint integrity is ensured as a result of seal welding between the tube
ID and the plug, and on-site hydraulic or pneumatic tests can confirm
leak tightness. Plugs have been successfully tested at 10,000 psi. In
thermal cycling tests, a plug/tubesheet joint was heated and plunged
into cold water ten times, with the joint remaining tight and leak-free.
Tubesheet Damage Absence
Explosive welding is a solid-state process in which a true metallurgical
bond is achieved inside the tubesheet or tube hole. The quality and
reproducibility of the weld is assured because the correct geometry is
designed into each plug and the proper explosive charge is
pre-engineered to match
Ease
of Installation
Installation requires minimal preparation and installation time. Special
machining is not necessary and hole tolerances are not critical, though
removing surface oxides from the weld area of the tube in necessary. If
the leak is at the tube-to-tubesheet joint, a section of the tube is
removed and the plug is installed to the tubesheet hole.
Plug Size Variety
Hole tolerances are not critical because the range of plug sizes
available is suitable for most tube bore sizes from 27/64” to 1”.
Plug sizes above 1” diameter can be manufactured upon request.
Easily
Installed in Limited Access Area
Ease of installation and the fact that the charge is initiated outside
the heater enables explosive plugs to be readily installed through the
manway openings. The nickel plug will bond metallurgically to virtually
any tube or tubesheet material used in feedwater heater construction.
Fast Response by Expert Technicians
TEi Services technicians are specifically trained, licensed, and
experienced in the installation of explosively welded plugs on all types
of feedwater heaters, under all kinds of conditions.