Product/Service

Tube-End Coating

Source: Plastocor Inc.
Tube-End Coating
Copper based tube alloys can be subject to selective erosion within the first foot of the inlet tube-end. Other tube materials can deteriorate because of galvanic or microbiological issues
Copper based tube alloys can be subject to selective erosion within the first foot of the inlet tube-end.
Other tube materials can deteriorate because of galvanic or microbiological issues.

Inlet-end erosion is due to turbulence present at the initial section of tube before laminar flow is
established. The degree of erosion depends on the nature and amount of entrained solids in the
cooling water, the type of tube alloy and its susceptibility to corrosion, water velocities,
micro/macrofouling of tube surfaces, and other design/operating factors.

Oulet-end erosion may also occur due to outlet flow induced turbulences.

The Plastocor Tube-End Coating is precisely applied in three coats of alternating colors to provide
complete protection. The 100% solids, high performance epoxy coating can be installed to any
depth and is performed in conjunction with the Tubesheet Cladding so as to confer maximum protection.
Each coat is approximately 2 to 3 mils thick and is applied further down the tube than the previous coat.

This three stage method creates a feathered termination, eliminating the chance of step-erosion,
a common problem with the use of plastic or metal inserts. This method can actually bridge small
perforations of the tube wall thereby repairing the tube and returning it to service. The need to retube is
therefore postponed or eliminated. The joining of the tubesheet cladding with the inlet coating creates
a uniform and smooth transition from waterbox chamber to tube interior. This reduces fouling
and turbulence which raises flow efficiencies. The tube ID is not significantly reduced which permits the unrestricted use of eddy current testing and most tube cleaning methods.
The Plastocor Tube-End Coating can indefinitely protect condenser tubes against inlet end erosion.

Plastocor Inc., 100 Research Road, Hingham, MA 02043. Tel: 781-749-5050; Fax: 781-749-5075.