Any Problems W/ PVC Pipe Touching Stand?

[GlockFu]

I am putting together a multi tank system and this is my first attempt at anything like this. When drilling the holes in the back of the tank I forgot to take into account clearing the back of the tank rack where the PVC pipe passes.

I test fit the PVC pipe into the bulkhead and it doesn't push on the rack but it either touches it or there's a teeny tiny bit of clearance. It's hard to explain what I'm talking about so I included a couple pictures below. Will this be a problem? Do I need to widen the hole in the back of the tank a little so I can move the bulkhead over a little bit?

 

[sleepydoc]

There are two issues I can think of:

1. If the pipes are touching the frame, they could transmit vibration and noise.
2. The more important issue is that if the frame is putting any pressure or torque on the pipes, it could cause the bulkhead to leak or fail.

 

[GlockFu]

These were my concerns too but i was more worried about causing a leak. I wasnt sure if these were real concerns or if they were just me being anal/paranoid. I really don't want to enlarge a good hole if it isn't necessarily but I will if i need to.

So you think its worth enlarging the hole?

 

[ca1ore]

It would worry me; but then I'm a charter member of Overbuilders Anonymous. Is there any 'slop' in the hole to allow you to move the bulkhead slightly away from the angle iron? Maybe using some ultraflex PVC instead of rigid would help? Overdrilling holes, particularly if the tank came that way (post drill tempering?) is not something I would be that keen to do.

 

[sleepydoc]

How would enlarging the hole help? If you do that, you limit the surface area of the gasket and make it more likely to leak. If you get a schedule 80 bulkhead, you have the same issues as before.

It looks close enough to the back of the tank that flexible PVC wouldn't have enough time to flex, but it's hard to tell. Is notching the 2x4 stud an option?

on a separate note, the bulkhead looks to be too close to the edge. How big is the hole and how close to the edge is it?

 

[GlockFu]

The hole wasn't there prior, I'm the one that drilled it. The pictures are with the bulkhead moved over as far as I could move it. The problem is not the wood, it is the iron part of the stand.

The Bulkhead is a 1-1/2" bulkhead and I used a 2-3/8" hole for it. The edge of the bulkhead is very close to the edge but the actual hole is 7/8" from the edge of the tank. I bought it used and it was predrilled for 1" bulkheads and I just enlarged the hole starting at the edge of the pre-existing hole. Is there a certain distance the hole needs to be away from the edge of the tank?

When I look around online, most places say the hole should be 2-3/8", some say 2-1/2" and some say 2-3/8" - 2-1/2". I was thinking that if I either elongate it or make it all around bigger by 1/8" then I would still be at a 2-1/2" hole and then the bulkhead would be able to be moved over 1/8" which I think would be plenty of clearance.

 

[woodnaquanut]

The reason you seen different BH hole sizes is different BH are different sizes. For a given BH size (1.5" in your case) ABS tends to need the smallest hole and Sch80 the largest.

Don't make the hole any larger than it needs to be. That just weakens the glass and reduces the amount of gasket available for a good seal.

If the pipe is not being deflected by the stand metal, I think you are good to go.

I share sleepy's concern about the hole being very close to the edge.

 

[GlockFu]

on a separate note, the bulkhead looks to be too close to the edge. How big is the hole and how close to the edge is it?

I share sleepy's concern about the hole being very close to the edge.

This tank is a 40 gallon plexi-glass tank. Because of the size of the tank and because it's plexi-glass I didn't think it would be a problem being drilled close to the edge. Was I wrong about that too???

 

[Gorgok]

Being plastic you are fine. It is hard to tell in the picture if that was glass or not.

 

[CuzzA]

As long as there is very little pressure on it I'm sure it will be fine. We use bulkheads hanging off the back of tanks and they hold X amount of pounds of water in the pipes. Also with the internal/external overflows the bulkheads are holding all the water in the external overflow. Both examples are probably putting more pressure on the bulkhead than one just slighlty touching a frame.

 

[woodnaquanut]

Being plastic you are fine. It is hard to tell in the picture if that was glass or not.

+1

I was wondering about the seam. It did look a bit odd for a glass tank.

 

[sleepydoc]

As long as there is very little pressure on it I'm sure it will be fine. We use bulkheads hanging off the back of tanks and they hold X amount of pounds of water in the pipes. Also with the internal/external overflows the bulkheads are holding all the water in the external overflow. Both examples are probably putting more pressure on the bulkhead than one just slighlty touching a frame.

+1

The main concern is that you don't want any torque on the bulkhead. If the pressure is vertical it's less of an issue. Ideally, your plumbing should be supported as well as possible so there is as little weight as possible on the bulkhead.

 

[GlockFu]

Awesome, thanks guys. Had me sweating there for a minute about being too close to the edge. Made me make a whole new thread! lol

I feel like I just dodged a bullet :hmm5:. It's been two steps forward, one step back with this project. All makes sense and sounds good, didn't really think about the weight of water, seems like there is definitely less than a couple pounds of preasure, thanks again!