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98%-6% sulfuric acid dilution pipe

98%-6% sulfuric acid dilution pipe

98%-6% sulfuric acid dilution pipe

(OP)
Our plant is looking to upgrade our sulfuric acid piping. Carbon steel is the current spec, which we will probably stick with for the transfer lines that handle only ~98% sulfuric at ambient temps with 40gpm. The problem area is our regen skids for our DI water systems. The mixing tees dilute the acid down to 6%, which produces a ton of heat. I looked at using Resistoflex multi-axis PTFE lined pipe, but the section after the mixing tee is 6". Does anyone have suggestions for some alloy that can handle this? We want to stay away from flanged connections, which is why I was looking at the Resistoflex multi-axis lined pipe. Maintenance would prefer an alloy that is weldable (field modifications). Thanks in advance!

RE: 98%-6% sulfuric acid dilution pipe

Carpenter 20 Cb-3 *might* survive and can be welded fairly easily.  You'll have to do a little research.

Keep the flow velocity real low in the CS lines--less than ~3 ft/sec.   40 gpm doesn't tell us anything by itself.

RE: 98%-6% sulfuric acid dilution pipe

diluter designs are available form the usual licensors. you are right about the heat but the real concern is proper mixing. 6" is way too short and the injector design is critical as is the adjacent piping arrangement. you might given mec a call, they specialize in small plants and have plenty of materials options to look at for the rest of your acid piping

RE: 98%-6% sulfuric acid dilution pipe

Hacksaw,
I think he means it's 6" dia., not length.

RE: 98%-6% sulfuric acid dilution pipe

(OP)
Metalguy is correct... 6" diameter. The mixing system is working fine, and we have no other problems that I know of. We're just wanting to get a plan in line to replace these sulfuric regeneration piping systems, one by one. I've done a ton of research, but am far from being done. We will also be upgrading our caustic piping, where it's needed.
I have spoken with MEC about their ZeCor system. I plan on sending out some drawings for a price quote, this week.

RE: 98%-6% sulfuric acid dilution pipe

I would look into Hastelloy for the mixing tee and the other places where you have high temps.  Hastelloy holds up to sulfuric over a wide ranges of conc and temps.  You better contact your accountant and tell them to get a second mortgage on the plant so you can afford it, though.  

PTFE Resistoflex may be your best bet if it holds up to the temp.  They have good article on their website.  

RE: 98%-6% sulfuric acid dilution pipe


okay on the pipe diameter being 6".

RE: 98%-6% sulfuric acid dilution pipe

Why not Z-Core fiberglass piping ? Lighter than lined pipe and no concern with the housing corroding.

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