100 Gallon barrel leaks :(

[Air21]

Howdy,

So a guy came over to the shop this morning with a dilemma. He is setting up 4 passivation tanks using 100 gallon plastic drums (polypropylene or polyethylene he didn't remember and I don't know that it matters).

What he's trying to do is run 3.5" shower drain fittings through the bottom of the barrels coupled to some drain hoses, but the shower drain flange is a persistent leak when the tanks are full in spite of all the silicone he gobs onto them. He observed that the barrel bottoms empty are concave and become convex when full. My

I'm not sure what made him think an aerospace machine shop would have the solution so I'm posing it here.

I told him my first thought was that he needed to increase the flange diameter to counter some of that flex and also to spread some of the 600lbs or so of liquid over a larger area instead of concentrating it. He says the tanks can't contain any metal due to the chemicals inside.

I wasn't able to snap any pictures, but do any of you have an idea how he's supposed to plumb this stuff in?

 

[ishiboo]

Shower drain flanges sound like a huge mistake, he should be using bulkhead fittings.

Nothing really sticks that well to those PE drums, the "right" option is to have the ports actually welded in. In lieu of that, Scotch-Weld DP-8005 might be an acceptable solution.

 

[ishiboo]

BTW, these "bolted" units are a really good option:

https://www.grainger.com/product/BANJO-Bolted-Bulkhead-Tank-Flange-WP131297/_/N-qu5?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/3DTH6_AS01?$smthumb$

 

[Kaizen]

guessing he's screwed. probably only choice is to plastic bond something. kind of like when they melt water pipes together.
he should have drilled into the hard sides near the bottom.

 

[LXCam]

Tell him to seal it with loctite 518. As long as the deviations in the drum are less then .050 to his flange that **** will probably work the best.

 

[BD1]

Yep, as stated by ishiboo ,bulkhead fittings .
https://www.google.com/search?q=bul...X&ved=0ahUKEwi48J_C4frMAhVC-2MKHUzbDxEQsAQIZg

 

[gayler]

Rough up the surface so with 80 grit and put a thick bead of P&L roofing and flashing sealer on it and tighten it down. Make sure he wears gloves because that **** wont come off.

 

[CNGsaves]

Also could "cage" the barrel with steel outer frame or whatever so that it doesn't flex when full.

 

[Stuart in MN]

Depending on where you are located, there may be a local company that specializes in chemical feed equipment for water treatment. Those places have all sorts of solutions for making connections to plastic drums. One big player in the middle US is http://www.hawkinsinc.com/groups/equipment/ but there are a number of other similar companies.

 

[rsanter]

Shower drain flanges sound like a huge mistake, he should be using bulkhead fittings.

Nothing really sticks that well to those PE drums, the "right" option is to have the ports actually welded in. In lieu of that, Scotch-Weld DP-8005 might be an acceptable solution.

This. We use similar tanks at work and they all have bulkhead fittings with gaskets in then

Bob

 

[TedU]

Uniseals are another option that might work
http://www.usplastic.com/catalog/item.aspx?itemid=89951