Boiler Conversion

[dzimme2]

Hello All,

As a regular visitor to the forum, I wanted to thank everyone for all of the valuable information available for reference. I have found myself frequenting the site in the past few months, but have not needed to propose my own question until now:

A customer recently inquired about having an old steam tube boiler converted into a hot water storage tank. Apparently the vessel is located on the top floor of a local hotel and is soon to replaced with smaller, more efficient boilers. However, given the location of the vessel and lack of roof-top cranes, it is likely impossible to remove the boiler from the building. Instead, the customer would like to know if it is possible to convert the boiler into a hot water storage tank (i.e. removing all tubes and tubesheets, weld new solid tubesheets in place of originals, weld 'doors' shut, etc... as necessary for safely sustaining pressure of water storage tank)

My company is an ASME certified repair facility, holding ASME, U, and R stamps. I am aware that re-purposing the vessel will likely fall outside of the scope of a typical "alteration" as per NBIC, but just curious if anyone out there has any experience or expertise regarding the situation at hand. Any and all information would be greatly appreciated, thanks in advance!

 

[chicopee]

Sure, hot water fire tube boilers are in use all the time. You'll need to change the appurtenances fitted on the steam boiler with appropriate appurtenances for the conversion. Piping on the other hand may be problematic since piping for steam application will be larger than that for hot water. There should be no alteration to the boiler itself, just rerouted piping. As a matter of fact, if you check out the nameplate of the boiler, you may find details relating to hot water application. Get the services of the boiler distributor for assistance in the conversion.

 

[GenB]

Removing tunes and install blind t.s. is a big and large alteration. Calc needed to see if new flat head will hold any pressure. Unless used for atmospheric or below 15 psi, NBC not needed otherwise you will kill someone during and or after rework... worst scenario.......genblr...

 

[dzimme2]

GenB,

I agree, it is a huge alteration, but the customer has almost no option. I also agree with you on the fact that all calcs will need to be done, but the water tank itself will not be in service above 15psi as it will likely be under city water pressure only. Therefore, the alteration will not need to adhere to NBIC, correct? Obviously the modifications will be completed to the highest personal standards, but I assume that I would not need to consult my AI for the alteration?

Chicopee,

Thanks for the insight. It may prove extremely useful for me to consult the original manufacturer for some information regarding the proposed modifications - I'm sure this isn't the first time they've received a similar request. As you stated, no work will be done to the shell itself except for sealing the doors closed. The tubes and tubesheet will be removed, new tubesheets welded in place to serve the same function as flat tank heads, then sealing the doors and all external pipe openings. In theory, I don't foresee a major issue, but I'm going to see the vessel for the first time later this afternoon.

Thanks again to all, keep the ideas coming!