Some help with HK style bulkheads please.

[Stealthy Ninja]

Hi, I live in Hong Kong and have recently decided to replace my old freshwater tank (which used to be a marine FOWLR tank) with a new saltwater/reef tank which has an in tank overflow thingy (not sure the exact name, it is inside the tank and has two holes cut in the bottom of the tank for input/output).

Anyway, according to the guy in the shop they will provide the following "bulkhead" style connectors. Since they aren't the normal bulkheads I see on forums, I have a couple of questions:

My question is, for this sort of thing should I put a gasket on the water side and the dry side or just the water side? Also, should I add teflon tape to the thread and/or silicone near the thread/gasket(s)?

Option 1 or 2 (gaskets):

Thanks in advance. I'm kind of new to plumbing.

 

[may2024]

If you use a gasket use one on the wet side only. I'm not a big fan of gaskets i like silcone myself. But like most things in this hobby both can endlessly debated.


My phone.

 

[Stealthy Ninja]

thanks may2024.

I've heard to use silicone combined with gaskets and also, contrary to that argument, that silicone will mess up the gasket (so don't use it). Now you're saying to just use silicone. LOL lots of debatable issues.

So only put the gasket on the water side. How about teflon tape? Needed?

 

[anarchy]

I've never used this type of bulkhead but what I do with threads is I run a thick bead of silicone at the beginning of the threads and screw it together and once it's tight some silicone should squeeze out and I just make sure to smooth it out with my finger to make sure it's solid. And gasket on the wet side. I only use gasket but of course endless debate

 

[StirCrayzy]

I like the gasket coated in silicone myself, and a bead of silicone at the base of the threads.
Problem with coating the gasket, is it lubricates the interface, and makes it very easy to overtighten, possibly damaging the BH or the glass itself.

 

[DaveK]

... Since they aren't the normal bulkheads I see on forums, I have a couple of questions:...

I think you are correct, they don't seem to b e bulkhead fittings. They seem to be a male adaptor, and slip to thread bushing. See this link (offsite) about half way down - http://www.savko.com/partlist.asp?pgid=3&ptid=14

Bulkhead fittings have a large flange for the gasket. A bulkhead fitting also has a different set of threads for mounting it and uses a special nut just to mount the fitting. They do not pipe threads for mounting the fitting. See this link (offsite) - http://www.savko.com/partlist.asp?pgid=2

Personally, I think the LFS either doesn't know what they are doing, or trying to commit a fraud upon you. I would not recommend the those sort of fittings your being shown. Get real bulkhead fittings, even if you need to go to a plumbing supplier.

 

[Stealthy Ninja]

I think you are correct, they don't seem to b e bulkhead fittings. They seem to be a male adaptor, and slip to thread bushing. See this link (offsite) about half way down - http://www.savko.com/partlist.asp?pgid=3&ptid=14

Bulkhead fittings have a large flange for the gasket. A bulkhead fitting also has a different set of threads for mounting it and uses a special nut just to mount the fitting. They do not pipe threads for mounting the fitting. See this link (offsite) - http://www.savko.com/partlist.asp?pgid=2

Personally, I think the LFS either doesn't know what they are doing, or trying to commit a fraud upon you. I would not recommend the those sort of fittings your being shown. Get real bulkhead fittings, even if you need to go to a plumbing supplier.

I think I need to go talk to the guy again. I will go in my lunch break today with a picture of a proper bulkhead and ask for those.

It could be I'm mistaken. He could have meant something else other than what I thought he was saying, since English isn't his first language.

If I need to I'll go check out a plumping supply store and get some myself.

Thanks for the advice everyone.

 

[Stealthy Ninja]

OK it seems my memory was slightly wrong.

Turns out they're like this:

or this (this one has no gasket):

The flange is a lot bigger than I first though. Also the guy confirmed you only put the gasket on the water side.

I asked the guy about the other type and he said that the standard type of "bulkhead" isn't for putting pipes into.

BTW these go in a hole at the BOTTOM of the tank (if that makes a difference) with pipes going up and down from them.

 

[Stealthy Ninja]

The flange side has grooves cut into it (I assume to let the rubber grip better). The female/nut side is smooth.

 

[DaveK]

OK it seems my memory was slightly wrong.

Turns out they're like this:
...

or this (this one has no gasket):
...
The flange is a lot bigger than I first though. Also the guy confirmed you only put the gasket on the water side.

I asked the guy about the other type and he said that the standard type of "bulkhead" isn't for putting pipes into.

BTW these go in a hole at the BOTTOM of the tank (if that makes a difference) with pipes going up and down from them.

The flange side has grooves cut into it (I assume to let the rubber grip better). The female/nut side is smooth.

The flange still looks very small to me. Most all the bulkheads I see here, in the USA, use a flange about 1/2" (12 mm) wide, for use with a flat rubber gasket. It's possible that you are showing us are something sold in your part of the world and not where I am.

Flanges are not usually groved, since you tend to want maximum contact area with the fitting and the tank. Although it may be possible that what your showing uses a special gasket.

The LFS person was completely incorrect about "the standard type of "bulkhead" isn't for putting pipes into". That's exactly what you do with them, and you can get the standard bulkheads with either slip or threaded connections for pipe. Note also that with a standard bulkhead, you can tighten the nut on it after installation. This would allow you to correct a minor leak. This is something you wouldn't be able to do with the product your showing us.

It is also possible that standard bulkheads may not fit properly in your tank. Then you wouldn't have much other choice.

I think it's worth a trip to a plumbing supply store and see what they have to say.

 

[Stealthy Ninja]

Thanks for the words of advice.

I'm looking into alternatives, though I guess the holes will be cut for these fittings. I'm going to duck over to a local hardware/plumbing supply store nearby my work to see if they have anything resembling a proper bulkhead. If I can buy some to try out I might just do it, otherwise I will probably be stuck with these fittings.

I'm thinking this is the "Hong Kong style" of doing these things. Sometimes Asia is like that, they don't do things the "right" way but somehow it still works.

I'm thinking if I'm forced to use these, I'll add some silicone and/or teflon tape to prevent the water flowing along the threads, causing a leak. Not ideal, but if I do it right it shouldn't leak. I mean apparently the fish tank shop does it this way all the time and they don't get leaks, so I'm hoping for the best.

I'll update these threads again in a few weeks when the tank is delivered and I have a chance to have a good look at them.


UPDATE:
I went to the local shop and they didn't have a clue about bulkheads... I'll keep searching but assuming I can't find an alternative:

Since this sort of connection (unlike a standard bulkhead) doesn't have a nut side (and a flange side) instead it seems to have two flange sides (male and female) that will pull towards each other when tightened. Is there any reason why I couldn't put a gasket on both sides of the aquarium glass so that the fixture will seal on both sides?

Please correct me if I'm wrong, but I'm thinking this design pulls evenly both ways so the gaskets on both sides will seal, stopping the water flowing out either from the tank or through the threads.

As suggested by this having two rubber gaskets:

 

[oceanwolf]

My tank came with metric sized bulkheads. Look for a 32mm bulkhead on google. That will be equivalent to a 1". The hole for that bulkhead needs to be 42mm. They are tiny bit smaller than English versions.

 

[Stealthy Ninja]

Thanks for the info oceanwolf. The shop guy has already told me the pipes will be 20mm and 30mm (20mm output to the main tank, 30mm on the return). So perhaps 20mm and 32mm bulkheads would do (depending on how 30mm pipe will fit into a 32mm hole, if it tapers slightly it might be OK).

I'm still looking into finding some of these proper bulkheads, but I'm afraid they aren't common here. I still have a week or so before the tank comes to track some down.

:fingerx:

 

[StirCrayzy]

The problem with adding gasket on the dry side is that the entire assy can flex and move possibly releasing pressure on the wet side.
You want a firm solid base for the wet side to clamp onto so all the pressure transfers to the compressed gasket on the wet side.

I can't belive you can't order in standard bulkheads to fit the holes...?

 

[Stealthy Ninja]

The problem with adding gasket on the dry side is that the entire assy can flex and move possibly releasing pressure on the wet side.
You want a firm solid base for the wet side to clamp onto so all the pressure transfers to the compressed gasket on the wet side.

I can't belive you can't order in standard bulkheads to fit the holes...?

Oh yeh that makes sense. Thanks for that, I was wondering where the gap in my reasoning was, what you said makes perfect sense.

Yeh I'm searching all over for bulkheads. One shop seemed to have some, but when he showed me they were brass...

Hong Kong has an area with a lot of plumbing supplies, I'm going nearby there tonight so if I have time I'll ask there. Otherwise, I'll see how it goes with these fittings I suppose. I mean it's not like they won't work, seems a lot of tanks in HK are done this way. Hong Kong/Asia (like I said) is like that sometimes, They just do things differently.

I suppose if push comes to shove I'll order some bulkheads online, issue is I've ordered live rock to go with the tank (already cured, that's the way it comes in Hong Kong) and I don't want that sitting in a bucket for weeks.

 

[StirCrayzy]

Rock in a bucket wouldnt be the worst situation. Fairly common actually, just keep it heated and circulating, and you can take your time with everything else.

 

[Stealthy Ninja]

Yeh you're right, I just looked that up and the time in the bucket won't hurt (will probably buy a large rubbish bin to temporarily store them in actually). No point rushing things. I won't need to heat it though, it's not that cold here. I've never needed to use a heater in any tank (chiller yes). Even in winter I can pretty easily maintain 25-30C in a tank just by using the heat generated by pumps.

Thing is I looked almost everywhere I can think of and I still can't find a "normal" bulkhead that would fit. I found one for 40mm and 16mm pipes (I'm using 30mm and 20mm pipes) but honestly they looked cheap (like something made for the inside of a toilet cistern) and not as good as the parts the LFS will supply anyway. For now i'll stick with their weird bulkheads, unless I stumble upon the real thing soonish.

 

[Stealthy Ninja]

Update, the tank comes on Wednesday. Couldn't find any normal bulkheads so far... but will keep looking.

I think I'll just go with what the shop always does (those weird "bulkheads") since it seems this is the "Hong Kong way" I assume it'll be fine.

I'll do the plumbing on Thursday... I'll keep this thread updated just in case anyone is interested.

 

[Stealthy Ninja]

Well, I did the plumbing but only minor leak testing so far (I used a lot of unions so I pulled one part out and ran some water through it, no leaks so far.

The shop guy said to use a gasket on both sides (of the "bulkhead") and run teflon tape around the thread (and use silicone) so I did all of that on Wednesday night (just after the tank came), I'm giving it a good 48+ hours before testing it (to let the silicone cure) before doing a test run (which I'll do on Saturday).

I made some minor mistakes with gluing the pipes (first time) but nothing I couldn't fix/adapt my design around. I will post pictures once I've got everything sorted.

 

[Stealthy Ninja]

Well everything went OK, no major leaks (only leaked in places I was pretty sure it would leak, and places it doesn't matter it leaks.

I ended up following the advice of the shop guy. Double gaskets, silicone and teflon tape. No leaks at all... so, so far so good.

Here's some pics for those who are interested: