This is a short presentation covering the insitu Electroless Nickel Platings of Heat Exchangers and Reaction Vessels.

1. Electroless Nickel Plating
Electroless nickel plating was developed in the late 40’s early 50’s.It is used today in areas
requiring uniform plating, high corrosion resistance and high abrasion resistance.
Electroless nickel plating is an auto-catalytic reaction used to deposit a coating of nickel on a
substrate. Unlike electroplating, it is not necessary to pass an electric current through the solution
to form a deposit. This plating technique used is to prevent corrosion and wear rather than
aesthetics.
Electroless nickel plating has several advantages versus electroplating. Free from flux-density and
power supply issues, it provides an even deposit regardless of work piece geometry as
demonstrated in the diagram below
Conventional Electroless nickel plating involves numerous heated pre-treatment and activation
baths, followed by one or more plating bath and then rinsing baths. The items for plating are
progressively immersed in each bath. This process severely limits the size and types of items that
can be plated and as such only smaller components are generally plated with EN.

2. Conventional Electroless Nickel Plating
Typical EN plating setup of 10 baths
Nitric acid used for striping and activation

3. Insitu Electroless Nickel Plating
Techcoat Services can Electroless Nickel Plate tanks and reaction vessels with Hi-Phos Electroless
Nickel offering outstanding corrosion resistance and overall durability. This plating can offer a far more
cost effective lining to that of inconel cladding. Each plating job is individually designed and
completed. Electroless Nickel Plating is vastly superior to electroplating and is used extensively
throughout the Oil & Gas and Resources industries in the most aggressive exposures (down hole oil
pipeline fittings). Until now works have been limited to smaller workshop applied items.
Techcoat Services has developed processes to plate Road Tankers, Reaction Vessels and Storage
Tanks.
This process is completed insitu, without the need for Nitric acid surface activation, pre-treatment or
post-treatment baths. The entire process is completed within the vessel being plated.

4. Insitu Electroless Nickel Plating & the Alumina Industry
Electroless Nickel Plating (EN) offers many benefits to the Alumina Industry,
EN has the following properties:
Outstanding corrosion and abrasion resistance
Inherently antiscale surface
Low coefficient of friction
High surface hardness, further improved with post heat treatment
Outstanding resistance to thermal shock
Internally non stressed and chemically bonded to the surface
Very high temperature resistance
Very good heat transfer

5. Insitu Electroless Nickel Plating of Heat Exchangers
Electroless Nickel Plating (EN) of heat exchangers would offer comparable heat transfer to that of
normal tubing, reduced rates of scaling and resistance to periodic acid descaling. This combination
of properties potentially results in Heat Exchangers that once plated do not need retubing (as a
result of corrosion/loss of wall thickness from acid descaling). The EN is highly resistant to corrosion
and any loss of metal due to acid washing would be the nickel and not the underlying steel and at a
far reduced rate to that of steel. The EN can be reapplied to reinstate its original thickness and thus
eliminate the need for retubing.

6. EN on Heat Exchangers
Comparable heat transfer to that if unplated steel
Improved flow and production (due to reduced rates of scaling)
Reduced cleaning costs (both in frequency and duration)
Elimination of retubing costs (both in terms of lost production and maintenance
costs)
Retubing replaced by less frequent and more cost effective EN replating

7. Insitu Electroless Nickel Plating

8. Insitu Electroless Nickel Plating