The Steamboating Forum

I would like some info on the fittings used to connect the generator tubes to the drums. Is there a modern equivalent? Suppliers? Does anyone have drawings available for said boilers?

Thanks,

wes

According to the ASME Boiler & Pressure Vessel Code, the common method of attaching tubes to the drum is by roller expanding the tubes, from the inside of the drums. This becomes difficult with smaller diameter drums.

One exception in the Code is to use ground joint fittings which are attached to the boiler tube, and seated into the drum, held in place by studs and nuts. Bryan Boilers are the only company that uses this arrangement to my knowledge, and they make watertube boilers small enough for steamboats in the 20-30 ft range. Look on their website to see tube replacement procedures.

It appears that the code will not allow simply welding tubes to a drum, although I have seen just that on Heat Recovery Steam Generators that are ASME Code compliant. These boilers have very small diameter headers that would not allow roller expanding, so the boiler tubes are fully welded to the headers.

I've seen the Bryan fittings which are quite clever. Rolled tubes are common and I've seen welded and silver soldered tubes.

The LIFU boilers I am interested in use a flare-like fitting that looks somewhat similar to hydraulic brake line flare fittings.

87gn@tahoe wrote:I've seen the Bryan fittings which are quite clever. Rolled tubes are common and I've seen welded and silver soldered tubes.

The LIFU boilers I am interested in use a flare-like fitting that looks somewhat similar to hydraulic brake line flare fittings.

Come on guys. One of our "Limey" cousins from "across the pond" should have that info for you.