Summary for sulfuric acid tank loop seal Discussion
93% sulfuric acid tank loop seal fill is the core issue here: Kent Lindholm asked what material should be used in a loop seal on an outdoor sulfuric acid tank overflow pipe after corrosion appeared where the seal met atmospheric conditions, and the seal was found plugged with a clay-like substance. In the reply, the answerer suggests the real problem may be the pipe material rather than the fill, recommending PVC for commercial 93% sulfuric acid service and noting that G.M. and Delco Remy use PVC piping. However, the answer also cautions that Alberta winter temperatures could make PVC brittle outdoors, and mentions a dual-laminate approach as another solution. The reply adds that 93% sulfuric acid will absorb moisture from air and eventually attack mild steel, and even raises lead as a possible alternative. Overall, the discussion points toward changing the piping/material system rather than simply choosing a loop seal filler.
Q. We have had corrosion on the overflow pipe off of our sulfuric acid tank (located outside). It occurred after the loop seal at the point it contacts atmospheric conditions. Upon inspection the loop seal, it is now plugged with a clay like substance? (sent out to be analyzed). Does anyone know what should be used to fill the loop seal. Something that will not react with the acid on one side, and atmospheric conditions on the other?
Kent Lindholm
plant operator – AB, Canada
2007
A. Hi Kent,
Thou art using, methinks, the wrong pipe material. Go and use PVC.
G.M. and Delco Remy use PVC piping for their commercial 93% sulfuric
…. but in Alberta the outdoor temperatures in winter would make PVC very brittle … then there’s the dual laminate approach to solve that.
That concentration will absorb moisture from the air and eventually will attack mild steel … coming to think of it, why not use lead?
Freeman Newton [deceased] (It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
A. Mineral oil is what we use in a CPVC pipe
Rob S
– Newington, New Hampshire, USA
June 20, 2012