Backyard Aquaponics
A place to discuss aquaponics

Greetings.

I am upgrading my system by adding a swirl filter, made from a 60 gallon blue plastic barrel.

I have decided to use a 1" threaded bulkhead and ball valve as a cleaning drain. This will be installed in the side, near the bottom. I'm wondering which side of the bulkhead should be inside the barrel. Should it poke in (with the nice face on the outside) or poke out (with the nice face on the inside)?

My first thought is that the flow of the debris would be better if it were poking out. I'm not sure of any other factors. Input would be appreciated. Thanks.

it depends on the type of bulkhead.

Some allow you to screw into the back/'bolt head' and for these it doesn't really matter.
In those cases just worth checking for flushness of fit - if there is an edge it is better pointing downstream.
(ie. try to keep smaller diameter going out into large diameter when you can)

If you have one that is the curved inflow without screw type then you need to have the thread going from inside out. You can push a piece of pipe etc into it on inside but it would have some risk if other way around.

In therms of strength/leakage it doesn't matter as you should have the rubber seals on both sides
In terms of being able to tighten the nut sometimes it helps to have the nut on the outside - eg in wicking beds where you are twisting the pipe for example to control water level.

you dont want the thread that you screw onto (outer thread) on the inside, unless you use A LOT of teflon on the thread, it may leak through the thread pretty much no matter how tight you have it because the seal doesnt block off the thread.

sorry for saying thread so much.

Thanks, folks! Onward with the project - threads facing out.

Sounds like you have it now. You probably also figured out that the size of the bulkhead depends on the size of the barrel as the curve makes sealing the curved edge of the barrel. Add a bead of good quality silicone on both sides of the bulkhead to be certain it doesn't leak around the sides. Also with any gasket and the addition of extra sealant it helps a lot to not tighten it completely until the next day. This lets the silicone harden in the shape of each side's curve and not squish out.

As for the bulkhead size, I tried to balance dealing with the barrel curve and being able to have a free flow for the debris, so I chose 1". To deal with the inside curve, I bought two more rubber washers. They are for shower drains and they are nearly identical to the washer that came with the bulkhead. I plan to stack them up on the inside with silicone between all of them. What do you think?

As long as they don't squish out while you are tightening it. Unfortunately two rubber washers together did not work at all for mine even with the silicone. They would not stay in place enough to tighten it to stop the massive leaks. Back to the drawing board and I came up this new plan; I took the rubber washer that comes with the bulkhead connector to a regular bench grinder and rounded the edges on the two sides where inside of the barrel curved. That helped a lot. I think it's a good thing you have extra rubber washers in case the ground shape gets messed up, as rubber cuts very quickly on a grinder, whoops for me! Plus I had to find the washers a few times as it tends to fly away. I had to go back to the hardware store and buy another. I wish I knew about the shower washer fit. I think I had to buy a new bulkhead connector to get the washer. Funny thing was all the bulkhead connectors on the shelf were missing at least one washer. I guess others have had an issue too. The silicone trick worked a charm as long as you let it set over night and tighten it just enough to shape it, but not deform it, that works great. I went to 1 - 1/2 PVC on my second system this technique worked so well.
Brian

you wont have a problem, dont over think it.
i use 50mm (2inch) on black olive barrels with no problem.
they would have a similar curve as they are about the same size as the blue barrels.

dont stack the rubber washers, if they slip and slide at all then it will make life harder.
try it normally first, you can always change it from there, but its harder to go back once you stuff around with it.

as you tighten it, it will flatten the barrel a bit, if it were a steel barrel that would be different.

if things dont fit perfectly (they will, 1' curve over a blue barrel is almost nothing), instead of ruining a bulkhead, use a heat gun to soften the barrel, then tighten.

About the only shaped bulkhead connectors I can think of are the ones for corrugated tanks.

These are a set of formed gaskets to match the profile of the wall of the tank that replace the flat gaskets which come with the bulkhead connector.

The 2" version is Philmac Part Number CTG50 but I can see no trace of it on Google. If anyone wants it I can take a photo of the Philmac book with the wholesale pricing obscured.

RRP is $25.98 on top of the cost of the 2" bulkhead at RRP $32.72

For a barrel the connector should just pull the wall flat, it would be more of an issue with a curved fiberglass or stainless steel tank.

To be clear, I have a Philmac account, and hence the book, but I'm not here to sell things to anyone!

Thanks, folks. So, Brian, for my 1": one washer, with silicone, light fit on the first day?