Porta Treatment on the KLR

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In early 2005, with the return of 2-6-2t Fox to service, the KLR became the first line in the UK to use the internal boiler water treatment known as 'Porta Treatment' (PT). Following initial success, by the middle of 2005 the entire fleet was put on the treatment regime.

Fox - The first locomotive in the UK to use PTBadger - On PT from the first steaming following a boiler overhaul

A trial application of PT on the KLR had been under consideration for some time. When a leaking stay and a crack appeared in the inner firebox of Fox in 2004 it was decided to trial the treatment on the locomotive once back in traffic. During the boiler repairs, done in two stages, considerably wasted stays (corroded and stress failure) were replaced. As much scale as possible was removed from the boiler but, due to inadequate access to some parts of the boiler it proved impossible to remove it all. However on reassembly of the boiler it was as clean as was practical in the circumstances.

Two examples of stays removed from Fox. Both are exhibiting signs of failure with the left hand stay being especially bad. June 11 2005
Two examples of stays removed from Fox. Both are exhibiting signs of failure with the left hand stay being especially bad. June 11 2005

Badger was also in the workshops over the same period following the expiry of the locomotive's ten yearly boiler certificate. The boiler was known to be suffering with pitting in the barrel and, as is normal, heavy tube corrosion. The condition of the boiler was such that a section of the barrel base had to be cut out and replaced. At the same time a full re-tube was carried out. On re-entry to traffic in June 2005 Badger was immediately placed on the treatment regime. As such it is expected the new section of the barrel and the new tubes will very rapidly have acquired a grey coating which protects them from corrosion etc. The grey coating is magnetite.

Heavily corroded, pitted and life expired. These are the tubes removed from Badger in early 2005. June 11 2005
Heavily corroded, pitted and life expired. These are the tubes removed from Badger in early 2005. June 11 2005

This is the section of the barrel removed and replaced due to heavy pitting. June 11 2005
This is the section of the barrel removed and replaced due to heavy pitting. June 11 2005

A close up of the worst section of pitting. The metal thickness has been reduced to less than 25% of its original condition. The application of Porta Treatment will prevent this from reoccurring. June 11 2005
A close up of the worst section of pitting. The metal thickness has been reduced to less than 25% of its original condition. The application of Porta Treatment will prevent this from reoccurring. June 11 2005

At the first couple of washouts conducted on Fox, as was to be expected, loose scale was found at the foundation ring. This scale had been removed from the boiler surfaces by the treatment as the chemicals concentrated in the boiler water. The boiler water has taken on the expected tea like colour and water in the tanks has a reddish tinge.

In addition to the very considerable benefits expected in terms of boiler repairs corrosion inhibition in the water tanks and cleaner piston and valve rods (due to pure steam now being supplied) have been noted.

A description of the system by Ian Screeton can be found on the KLR volunteer's website. Click here and scroll down to the March 9 2005 entry.

More information on Porta Treatment can be found here.

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