In our club we have been taking the cladding off our road vehicles every 7 years, and removing blow downs and mud holes, and inspecting the inside of the boiler with a camera, and the outside visually. we also have a thickness tester and test the thickness of the platework if we think it is needed. We have found that if some types of insulating material have been used it holds water, and this can rust the outside of the boiler barrel. This can be addressed once the cladding is off.

Chris Gunn

Nigel,

9.2 gives the “tester” the discretion to extend the 7 yr requirement to 10yrs (in line with commercial requirements although you did say you didn’t want a comparison!).  If extending to 10 years then a reason needs to be given.

The 7yr requirement of the code is not well thought out in my opinion.  The first 1.5 hydraulic on a new steel boiler can be given for 4 years and thereafter every 2 years (12.5b) so effectively multiples of 2 years, so at year 6 from the last cladding removal to comply with the code you can only issue a 1yr hydraulic cert.  What is special about 7 years?  If the scheme wishes to be conservative then why not go for 6 yrs or impose an annual hydraulic (not a clever idea!)

Our club also has an endoscope and ultrasonic thickness measuring equipment.  At the 2 yearly hydraulic test we do a thorough inspection of major threaded fittings including fusible plug, blow down’s, wash out plugs etc.  Most steel boilers tested have been in the club for many years and there is documented history of previous inspections.  Our inspectors take a pragmatic and practical view and take into account the age of the boiler it’s construction and original material thicknesses, treatment regime and the lagging material (if any) and generally extend the trousers down inspection to 10 yrs as long as under hydraulic there is no evidence of leakage under the cladding or behind the horns.  Given that the outer firebox is generally thicker than the inner, the wastage on the inner firebox is a reasonable guide to general condition when combined with an internal inspection with the scope.  There have been a couple of larger scale (4”) traction engines come into the club with uncertain prior history and poor documentation, these have been required to remove all lagging but I don’t think there has been sufficient concern to require the removal of the horn plates.

Whilst the club scheme has to have a simple yard stick and time has been chosen, there are other factors that undermine the validity of time.  Some boilers only get used a few times every year and are properly dry stored in between, others may be running 20 or 30 times a year.  My own 6” engine which I only got running last year and only attended 2 events was steamed 7 times between July and Sept.  This year I am hoping to do 10 events which are all 2 or 3 day affairs so should be steamed at least 25 times for 6-8 hrs a session.  So 7 years might be reasonable for me but probably not for someone using their boiler only occasionally (if they are looking after it properly).

One of the worst things for a boiler (copper or steel) is raising steam too quickly leading to unequal expansion, I cringe seeing some of the supercharged electric “blowers” you often see people using!

Paul.