Bulkeads for blockheads

[redfishsc]

I am about to plumb up my first bulkhead, and have a couple of quick questions.


I assume that I need to PVC cement the PVC into the bulkhead. When, later, I want to remove the bulkhead or move the tank, I assume this means I'll have to slice the PVC pipe.

Is there any way to make this more removable? This is on a tank that I may move in the next couple of months, although I'm not totally sure. This tank is the "upper" tank on a two-level stand (two small tanks stacked), and I'm connecting the two tanks together. This means that if I want to move the top tank, I'll have to totally remove the PVC from it to be able to move it. If it's all cemented together, I'll have to cut it (not easily done in this cramped space).


Lastly, how tight do I need to tighten the nut? Just snug enough for a good seal, I assume.

Tomorrow I can try to get some pics if it helps.

 

[dean1977]

I like to use hayward bulkheads(from bulkreefsupply) that are threaded on the insides of both ends. This way you can remove the plumbing and reuse the bulkhead. I use pink teflon tape and I use silicone lubricant(from marine depot) which is just like on oil on the rubber gaskets (and o-rings in pumps) to keep the rubber in good shape.
Definately dont over tighten the bulkhead either because the gasket will bind up and leak. A strong hand tighten should be good. Dont attach the plumbing in a way that pulls on the bulkhead.
Make sure the bulkhead is the perfect size for the hole.

 

[James77]

You can put some type of union or threaded fitting. I personally plumb it directly to the pipe. If I move it, I cut the pipe and use a coupling later.

A quarter turn past hand tight is about how tight you want it. Too tight, and they are prone to leak.

 

[RussM]

Re: Bulkeads for blockheads

<a href=showthread.php?s=&postid=15065801#post15065801 target=_blank>Originally posted</a> by redfishsc
I assume that I need to PVC cement the PVC into the bulkhead. When, later, I want to remove the bulkhead or move the tank, I assume this means I'll have to slice the PVC pipe.

Lastly, how tight do I need to tighten the nut? Just snug enough for a good seal, I assume.

That's why I generally only use threaded (on the non-flange end) bulkheads. On the flange, side, I select threaded or slip/cement depending on the particular application. They may cost slightly more, but are worth it IMHO.

1. The bulkhead gasket ALWAYS goes next to the flange, regardless of which side is wet or dry.
2. Never use any form of sealant or lubricant on bulkheads.
3. Tighten to a firm finger-tight, then tighten approx. 1/4 turn more.

 

[dean1977]

BTW, I 'm just speaking from years of personal experience and whats worked best for me. I have had to replace a few bulkhead gaskets over the years and my gaskets last much longer with a drop of silicone lubricant made for rubber o-rings. Saltwater dries gaskets out. I have also spoke with the people at hayward and they said its find to do. I have 14 holes in the bottom of one of my present tanks.

 

[RussM]

<a href=showthread.php?s=&postid=15066323#post15066323 target=_blank>Originally posted</a> by dean1977
BTW, I 'm just speaking from years of personal experience and whats worked best for me. I have had to replace a few bulkhead gaskets over the years and my gaskets last much longer with a drop of silicone lubricant made for rubber o-rings. Saltwater dries gaskets out. I have also spoke with the people at hayward and they said its find to do. I have 14 holes in the bottom of one of my present tanks.

I agree that silicone grease, prudently used, can extend the life of the gasket. I'm a big fan of the stuff, actually. The problem is that the grease makes it too easy to overtighten & therefore deform the gasket, and possibly overstress the flange. Many of us reefkeepers like to think we're Mr. Macho, and torque the crap out of plumbing fittings

 

[redfishsc]

This is just what I was looking for!

Thanks!

Matt