Why is everyone using schedule 80 on CL's?

[triggerfish1976]

I have been reading several build threads lately that recommend schedule 80 PVC fittings and I was wondering why these are being recommended for close loop applications. I am not a plumber but I would imagine that schedule 40 should be more than enough especially when people are mainly using non-pressure rated pumps for their CL's.
It seems to mainly come up when recommending bulkheads.

[dhnguyen]

There is no need for using SCH80 in a CL setup IMO

SCH80 PVC pipes are made for high pressure (we're talking industrial application pumps here) so unless you are using some extremely high pressured pumps there's no need for the extra expenditure.

SCH40 will more than acommodate anything we can throw at it in this hobby

[luke33]

Agreed with above

[dedfish]

if I had to guess it's all about color.

[triggerfish1976]

Originally posted by dedfish
if I had to guess it's all about color.

The funny thing is I see this brought up on most of the threads.
I understand that schedule 80's inside diameter is smaller due to the increased wall size so someone is always stating that you you are able to get more pressure but I don't see how this would make a difference if only the bulkhead is sch. 80 and not the rest of the piping?

I also understand the reasoning that they are just better quality bulkheads but I just dont know if the difference in quality really effects our systems.

[Bebo77]

Originally posted by dedfish
if I had to guess it's all about color.

lol... yup... thats why i used it...

[mg426]

I used a couple cause I had them laying around. Schedule 40 is plenty for our needs. I have even used thin wall PVC tubing with not a hint of trouble.

[steveweast]

It has nothing to do with pressure ratings....and it has everything to do with the wall thickness. There are two failure points on every bulkhead....the nut that clamps the bulkhead down....and the female threaded fitting that attaches piping to the bulkhead. The later is the most common failure point. If you overtighen a male threaded fitting into a female threaded fitting (easily done), it will split apart (and maybe after weeks or months without failure). Using 80 schedule gives you more room for error since it is a thicker material. Using 40 schedule bulkkheads is just foolish and needlessly taking a chance to save a few bucks. Female threaded fittings should be avoided at all cost....there's a reason why their use is a code violation in the residential plumbing code. If you must use a 40 schedule bulkhead, at least use a slip fitting....although, you still will have exposure at the nut. It's about risk reduction.

[triggerfish1976]

I have properly used schedule 40 bulkheads for years and have never had a problem.
When used properly does anyone know of any schedule 40 bulkhead's that have failed?

[dhnguyen]

Yeah but Steve even with the best material and tools if used improperly will break

[steveweast]

Originally posted by dhnguyen
Yeah but Steve even with the best material and tools if used improperly will break

Absolutely, of course it could still fail....nothing is fail safe .....but why not have the added insurance for a few extra bucks ? It's just very cheap insurance against a common failure point. I'm all for saving money...but, not in this area.

The usual failure goes something like this....

The bulkhead starts to drip at the male adapter that screws into the bulkhead....the adapter gets tightened until it stops (instead of re-taping the male adapter).....the bulkhead then cracks from the excessive tension sometime over the next month....creating a mess.....

OR

the bulkhead is leaking from the seal.....which upon the nut is racked down some more.....then it breaks....resulting in another mess.

These situations could be helped by using a little beefier bulkhead. If it is installed correctly....then fine....but that extra capacity is nice to have....and all for just few dollars more. If you want to go the cheap route and use the 40 schedule, then great...live it up.....but, I'd rather have the peace of mind. Too much can and will go wrong in this hobby...and I try to reduce my risk where possible.

[dedfish]

Originally posted by steveweast
Absolutely, of course it could still fail....nothing is fail safe .....but why not have the added insurance for a few extra bucks ? It's just very cheap insurance against a common failure point. I'm all for saving money...but, not in this area.

The usual failure goes something like this....

The bulkhead starts to drip at the male adapter that screws into the bulkhead....the adapter gets tightened until it stops (instead of re-taping the male adapter).....the bulkhead then cracks from the excessive tension sometime over the next month....creating a mess.....

OR

the bulkhead is leaking from the seal.....which upon the nut is racked down some more.....then it breaks....resulting in another mess.

These situations could be helped by using a little beefier bulkhead. If it is installed correctly....then fine....but that extra capacity is nice to have....and all for just few dollars more. If you want to go the cheap route and use the 40 schedule, then great...live it up.....but, I'd rather have the peace of mind. Too much can and will go wrong in this hobby...and I try to reduce my risk where possible.

All of these situations could be avoided by an intelligent installer. If you don't know how to operate a bulkhead buying a beefer bulkhead isn't going to fix that. It may hide it, but not fix it. I'd rather learn how to bulkhead rather than waste money. Things in this hobby are expensive enough. Knowledge is the answer to peace of mind.

[triggerfish1976]

Thanks for the input thus far and I hope more people chime in. Given the amount of times I have seen this topic brought up in build threads I thought it needed its own thread.
For the record, I was not intending for this to become a sch. 40 vs sch. 80 debate but I think it is safe to say that sch. 40 is fine as long as you know how a bulkhead works which anyone in this hobby should know.
Like dedfish said, knowledge = peace of mind and it will also save you a large amount of money in this hobby because it doesn't just stop with bulkheads.

[CMcNeil]

sch 80 is soooooooooooo overkill,i use thin wall(thinner than sch-40)it has a larger ID than sch-40.id say the wall is thickness is less than 3/32" and i have darts pumps plumbed to it.

[steveweast]

Originally posted by dedfish
All of these situations could be avoided by an intelligent installer. If you don't know how to operate a bulkhead buying a beefer bulkhead isn't going to fix that. It may hide it, but not fix it. I'd rather learn how to bulkhead rather than waste money. Things in this hobby are expensive enough. Knowledge is the answer to peace of mind.

Couldn't disagree more.... the allowable stresses are greater on a sch 80....resulting in greater tolerances. To me, peace of mind is directly related to a factor of safety and redundancies.....not saving a few bucks. The difference in cost is so marginal that it isn't even a decsion to me. There's nothing wrong with Sch 40....I just feel that the 80 is a superior product and well worth the minimal cost.....if you feel differently, that's your choice.

[steveweast]

Originally posted by checkinhawk
sch 80 is soooooooooooo overkill,i use thin wall(thinner than sch-40)it has a larger ID than sch-40.id say the wall is thickness is less than 3/32" and i have darts pumps plumbed to it.

I agree with this....for piping. But, we're not talking about water pressure here...we're talking about torque on the threaded fittings (the achilles heel of a bulkhead)....and a beefier thread has a greater allowable stresses.

I think I'm done here. I just wanted to make the point...that while 40 will work, 80 will allow for error for a minimal cost.

[sjm817]

The OP wasn't asking about bulkheads. Sched 40/80 bulkheads, and pipes and fittings are different discussions.

Sched 80 bulkheads are nice. For pipes, sched 80 is way overkill and has a smaller ID. Use sched 40 and even better, the thinwall sched 26 has a larger ID.

FWIW, my setup has 7 sched 40 bulkheads. No issues here.

[dedfish]

Originally posted by steveweast
Couldn't disagree more.... the allowable stresses are greater on a sch 80....resulting in greater tolerances. To me, peace of mind is directly related to a factor of safety and redundancies.....not saving a few bucks. The difference in cost is so marginal that it isn't even a decsion to me. There's nothing wrong with Sch 40....I just feel that the 80 is a superior product and well worth the minimal cost.....if you feel differently, that's your choice.

If your disagreeing with me on a cost factor fine. But my main point was that a bulkhead properly installed will not cause any problems. The problems you describe are due to the person not knowing how to properly use a bulkhead. Don't over tighten anything and use plenty of teflon tape on threads.

As far as the OP I still think it's color.

[flyyyguy]

I use cheap bulkheads and schedule 40 piping and fittings everywhere...if I didnt you could add about $400 to a fairly expensive CLS as it is.........800 extra if you count my other tank too.

key is using clear primer if you want it to look good...no purple streaks, and plumbing with a relaxed fit so there is no stress on bulheads. silicone on any threaded fittings instead of polumbers tape so you dont have to thread tapered fittings in very far to stress anything

i think it looks ok with white pipe for the savings

[triggerfish1976]

To clarify, I was talking about bulkheads when I started this thread but the discussion can include pipe and other fittings.

[RokleM]

Personally, SCH80 bulkheads are much easier to deal with than SCH40, as well as being beefier. They seem to take a bit more stress, the nut is typically bigger which makes tightening for us with big hands easier, etc.

It boils down to the whole overbuilding conversation that ALWAYS comes up in stands. If building it a bit beefier is easier or makes you feel a bit more comfortable, go for it. Just because a stand can be made from only 1/2" or less plywood doesn't make it necessarily the best idea in all cases. Unless you're outright wasting materials to just do it, just doing the base minimum isn't always the best way to go

[steveweast]

Originally posted by dedfish
If your disagreeing with me on a cost factor fine. But my main point was that a bulkhead properly installed will not cause any problems. The problems you describe are due to the person not knowing how to properly use a bulkhead. Don't over tighten anything and use plenty of teflon tape on threads.

As far as the OP I still think it's color.

Agreed....a properly installed bulkhead...whether 40 or 80....should work just fine. My point was just that...for a few dollars more....the 80 offers a greater tolerance. It's a personal choice whether that extra cost is of benefit or not....for me....it is.

Perhaps my advocacy of 80 bulkheads stems from my using mostly 2" and 3" bulkheads where I need to use large channel locks to tighen those nuts....I don't use anything less than a 2" bulkhead.

I also thought that this discussion was bulkheads only....using 80 piping and fittings doesn't add much....IMO....except for maybe female adapters which can suffer in an over-tightening situation. I only use 80 piping and fittings on my cold water reef....but, that's mainly for condensation reasons.

[steveweast]

Here's another thought....perhaps a bulkhead's location should also play a part in whether to use 80 or not. If a bulkhead were located in a sump, overflow, or high on the tank's wall, it's quite easy to replace if something were to go wrong.....but.....if a bulkhead were located on the tank's bottom, that would necessitate a tank's draining to replace.

[tylorarm]

Didn't 'invincible' just have to drain his beautiful tank because of a leaking sch 40 bulkhead in the bottom of his tank? Didn't leak for a while until he changed plumbing attached. The extra tolerance of sch 80 might have helped.

[discotu]

don't sch 80 bulkheads require a larger hole too? That may be a limiter if holes are already drilled.