We have another batch of stainless elements in stock. This type is
proving to be far superior to the standard copper superheater designs.
Many of our customers have cut off their existing copper superheaters
and joined the stainless on, noticing a big difference in improved loco
performance and longer service life. The stainless stands up to the
extreme heat of the fire, and also a harder metal to resist cinder
erosion.
One of the improvements with the stainless type is the
higher temperature of steam because the stainless superheaters can
extend well over the firespace. The steam gets much hotter and dryer in
"radiant" superheaters than the common "convective" copper types.
There is more economical use of boiler steam & water and an improved
performance at the cylinders. Higher temperature steam gives more
power before condensing.
Additionally, the return bends are
neatly TIG welded, not constricting the gas path within the superheater
flues, as compared to some designs of copper elements. Some of the loco
repairs we have done in the past has revealed the existing copper
elements were hardly working at all, and the huge return bend blocks
served no other purpose than to block off the flues! In that case the
boiler steaming capability was inhibited by having these elements
fitted. The stainless elements we supply will not constrict the boiler
flues, and easy to fit a tube brush down the flues for cleaning.
How
do you join the elements to the header? We recommend a liberally silver
soldered joint as near as possible to the superheater header. Typically
a 45% silver solder (with cadmium) is well suitable, just remove the
outer oxide layer off the elements with emery. We have also used the
standard silver solder flux "Comweld, Silver brazing flux No. 2" with
success. The trick is to not overheat the stainless, as the oxide layer
will return, and you will have to clean it off and start over.
According to our silver solder manufacturer, the 45% CAD silver solder
is formulated for joining stainless steel to copper, and doesn't waste
away due to the dissimilar metals being joined.
Our superheaters are...
Seamless 316 grade stainless tube
Standard length (1m for 3/8", 600mm for 5/16"), you cut to suit your loco
TIG welded by pressure welding company
Purged with gas while welding (no weld slag inside tube)
Hydro tested to 200psi to confirm no leaks
If
you would like to invest in the performance and long service life of
your superheaters, why not give these elements a go in your loco.
Check out the "PRODUCTS" page of our website for pricing and details
www.npwoolley.com
No comments:
Post a Comment
Leave us a comment!