Should you buy a used boiler for your brewery?
Nope, Never Ever, No way, Jose, Negative. I believe I made my point. I get it; you can save lots of money by purchasing a used boiler. To see why I recommend a new boiler rather than a used one, consider this:
From day one, every steam boiler starts to corrode. Each time the boiler shuts off, the system fills with air. When air, steel, and water mix, rust develops. The amount of rust depends on whether the owner used quality water treatment and did the proper maintenance. I would wager not.
You have no idea if the original owner did maintenance on the boiler and a steam boiler requires maintenance. The inside of the used boiler could have scale or damage. Scale forms on the hottest surfaces and impedes the heat transfer. Eventually, it causes a leak.
If the boiler was used for a space heating application, it was most likely operated at a pressure around two psig. The operating pressure for a brewery steam boiler is almost six times that pressure. I would be very nervous operating the boiler which was used to working at two Psig at that elevated pressures. There was a movement a few decades ago to convert steam boilers to hydronic to cut energy costs. The boilers were used to operating at 2 psig steam, and after the transformation, they were operating at 20-30 psig water. Many of these boilers started to leak after the first year.
The life expectancy of a steam boiler is 25 to 30 years if they are correctly installed and maintained. I have seen boilers only a few years old develop leaks because of the lack of maintenance or water treatment.
A new boiler will appear to cost less than a used one, but that may not be true. A scaled boiler will cost you more in repairs and operating costs. Also, the used boiler may develop a leak much faster than a new boiler.