Installing bulkhead onto side of sloped container?

[victorhooi]

Hi,

I know this isn't strictly a reef-specific question, but there's been so much helpful info here on RO systems, plumbing and pH/EC testing, I thought I'd ask .

I'm helping my parents out with a basic hydroponics setup for their plants, and I need to install a bulkhead for 2" (50mm) PVC Pressure Pipe into the side of some square 27L plastic containers.

Reading around, it seems like I can either use a traditional bulkhead, or something called a "Uni-Seal", which is good for curved surfaces.

I was intending to use these bulkheads - Current Culture H2O UC Spin-Tight Bulkhead 2", which are meant to be very good.

However, the issue I've realised is that the sides of my container are flat - but there's an incline or slope to them. They're around 85 degrees from the horizontal, rather than 90 degrees:

I assume this is going to going to cause issues though, due to the pipe sloping between containers.

The black plastic container is made of PP (polypropylene) and the plastic is roughly 2mm thick.

Does anybody have any advice or tricks here, or any suggestions here?

Somebody online mentioned using a heatgun to try and melt/soften the plastic. However, will there be enough give in the plastic to get the bulkhead to sit vertical? I figured surely the plastic won't allow that much deflection? And will it cause any issues structurally, or leaks later on?

Or would a Uni-Seal be better here? I figured the bulkheads would be a more robust, long-term solution, and less mucking around during installation.

Thanks,
Victor

 

[USN74NMCB]

Is the left or right off feom the center more 90 degres up and down then the center where you have the pipe sitting in second picture? As you could off set to obe side if it is, or coming out of the bulkhead use flexiable spa pvc to go between the two containers. Just two different thoughts from the pictures you provided. Just from looking at container the center section looks sloped but the left and right side look to be flater and not sloped.

 

[victorhooi]

Is the left or right off feom the center more 90 degres up and down then the center where you have the pipe sitting in second picture? As you could off set to obe side if it is, or coming out of the bulkhead use flexiable spa pvc to go between the two containers. Just two different thoughts from the pictures you provided. Just from looking at container the center section looks sloped but the left and right side look to be flater and not sloped.

I just checked - and unfortunately both sides are also 85 degrees (they're just set in a bit...no idea why...maybe for aesthetics? Lol).

Appreciate the suggestion though!

 

[UncommonSense]

Does the pipe absolutely need to be 2”?

And, does the system absolutely need to be pressure rated (beyond a few PSI)?

The immediate issue I see is that any bulkhead fitting is designed to have the requisite sized plumbing fitting inside it; there’s the additional diameter of the bulkhead body, then flange/locknut to account for, too… — the stepped plastic wall there would not allow a 2” bulkhead to be mounted so low…


— Given that there’s some flex from the container, I’d measure out to see if a 2” bulkhead would fit offset to one side, on that wider flat surface… then, you can use a heat gun or similar to heat bend the PVC…

— an alternative option is using at least short lengths of large flexible hose to adapt between container and rigid pipe!

 

[KrisReef]

The issue I see is that you don't have enough flat surface area to seat a 2 inch bulkhead. The flange and seal will not sit in the space shown in the image.

 

[Isaac Alves]

What about a uniseal? Would that be more forgiving to the slope?

 

[jsmkmavity]

What about the bottom? If its flat you could install the bulkhead there and add a 90° elbow and elevate the tank with a frame and plywood and drill or cut a hole for the pipe.

 

[UncommonSense]

I suppose we should also clarify; what hydroponic method is being employed here? (As it pertains to plumbing design restrictions)

— it appears to be media based?

— if I had to guess… Dutch bucket method, or Ebb and flow?

If no media, Deep Water Culture?

 

[JumboShrimp]

Raise up on cinderblocks, expose enough of the flat bottom to make your connection there.

 

[victorhooi]

Does the pipe absolutely need to be 2”?

And, does the system absolutely need to be pressure rated (beyond a few PSI)?

The immediate issue I see is that any bulkhead fitting is designed to have the requisite sized plumbing fitting inside it; there’s the additional diameter of the bulkhead body, then flange/locknut to account for, too… — the stepped plastic wall there would not allow a 2” bulkhead to be mounted so low…

I realised afterwards that my photo with the pipe was a bit confusing - sorry! That photo was meant to show scale (i.e. relative size of the pipe adn box).

Here's a better photo, showing the flat area, where I was planning to install the bulkhead:

That are is 70mm wide at the bottom:

And around 135mm wide in the middle:

And yes, apparently 2" is the minimum pipe size people say you should use - any smaller, and you risk stray roots clogging up the tubes.

I suppose we should also clarify; what hydroponic method is being employed here? (As it pertains to plumbing design restrictions)

— it appears to be media based?

— if I had to guess… Dutch bucket method, or Ebb and flow?

If no media, Deep Water Culture?

You're right - I should have specified - I'm doing "Recirculating Deep Water Culture", similar to the "Under Current" systems from Current Culture H2O. Basically, it's like DWC, except there's a single shared reservoir, and this gets pumped through all of the other tanks before coming back.

The idea is you only need to adjust nutrients, pH etc in that one reservoir (although I suppose the flip side is, if you screw it up...well....)

And, does the system absolutely need to be pressure rated (beyond a few PSI)?

The water level will be an inch or two beneath the net pots at the top - so let's estimate 20L of water per pot.

I'm guessing people here will correct me if I make a mistake - but according to Wikipedia, the formula for hydrostatic pressure (simplified for water) is:

• ρ * g * z

z is my height - let's say 28cm = 0.28m.

That gives me a pressure of around 0.40 psi at the bottom of my tank. Does that seem realistic?

What about the bottom? If its flat you could install the bulkhead there and add a 90° elbow and elevate the tank with a frame and plywood and drill or cut a hole for the pipe.

Raise up on cinderblocks, expose enough of the flat bottom to make your connection there.

That's a clever idea - haha.

I'd prefer to install it on the ground, if possible (less to go wrong, and my parents are a bit older - I'm worried something might topple over. And I don't think they'd be strong enough to lift them). Although I'll keep that idea in my back pocket - might need it!

 

[twentyleagues]

The problem is as you expect since the panel is angled the pipe will be angled. Other than that and connecting the pipes it is not an issue. Uni-seals will not help or fix the issue I also find them to leak after time more so than true bulkheads. I like the idea of heating and bending the pipe a bit to match or using spaflex.

 

[UncommonSense]

That gives me a pressure of around 0.40 psi at the bottom of my tank. Does that seem realistic?

That’s pretty much spot-on for distilled water! The difference between distilled and even saltwater is quite small, too!

It does answer the question of whether or not the pipe itself needs to retain its 100+PSI pressure rating, though!


If it was my project, I’d set something simple and non-flammable on a non-flammable table, making your target angle (basically, a simple jig)… then, I’d heat bend each length of PVC pipe which mates to a bulkhead to that angle!

— a heat gun, or similar will be able to heat the PVC up enough to make it flexible… just do this in a well ventilated area!

— pick your spot on the pipe to make the bend, target that spot with heat, rotating the pipe to heat the circumference evenly… it’ll turn into a wet noodle once heated sufficiently, but you don’t need to take it that far to get a bend into it!

— this is the budget option; 15-30cm of flexible spa hose, with a barbed adapter and hose clamp at each end between bulkhead and PVC pipe would be superior only in that it provides flex while in operation, at appreciable extra cost!

 

[twentyleagues]

I am also wondering why you couldnt just use 1" bulkheads and pvc. I have made many sumps from totes and these square hydroponic buckets over the years and pretty much either used 1 or 1.5" bulkheads depending on flow rate and pvc. I do like the flexible pvc for these but I have not found it in larger than 1.25". Doesnt sound like you are going to have a lot of flow with this set up.

 

[Dread Pirate Dave]

Hi,

I know this isn't strictly a reef-specific question, but there's been so much helpful info here on RO systems, plumbing and pH/EC testing, I thought I'd ask .

I'm helping my parents out with a basic hydroponics setup for their plants, and I need to install a bulkhead for 2" (50mm) PVC Pressure Pipe into the side of some square 27L plastic containers.

Reading around, it seems like I can either use a traditional bulkhead, or something called a "Uni-Seal", which is good for curved surfaces.

I was intending to use these bulkheads - Current Culture H2O UC Spin-Tight Bulkhead 2", which are meant to be very good.

However, the issue I've realised is that the sides of my container are flat - but there's an incline or slope to them. They're around 85 degrees from the horizontal, rather than 90 degrees:

I assume this is going to going to cause issues though, due to the pipe sloping between containers.

The black plastic container is made of PP (polypropylene) and the plastic is roughly 2mm thick.

Does anybody have any advice or tricks here, or any suggestions here?

Somebody online mentioned using a heatgun to try and melt/soften the plastic. However, will there be enough give in the plastic to get the bulkhead to sit vertical? I figured surely the plastic won't allow that much deflection? And will it cause any issues structurally, or leaks later on?

Or would a Uni-Seal be better here? I figured the bulkheads would be a more robust, long-term solution, and less mucking around during installation.

Thanks,
Victor

Does the pipe need to enter in a straight shot on that side? When I was using a 7 gallon trash can for an external refugium, I used regular bulkheads with 90 degree elbows. Even though one end of the elbow is connected at an angle with the container, the other end can be perfectly level.

 

[UncommonSense]

I am also wondering why you couldnt just use 1" bulkheads and pvc. I have made many sumps from totes and these square hydroponic buckets over the years and pretty much either used 1 or 1.5" bulkheads depending on flow rate and pvc. I do like the flexible pvc for these but I have not found it in larger than 1.25". Doesnt sound like you are going to have a lot of flow with this set up.

Ah! in this application, the plant’s roots will end up growing into the plumbing over time, clogging things up and causing a flood if huge plumbing isn’t used!

 

[twentyleagues]

Ah! in this application, the plant’s roots will end up growing into the plumbing over time, clogging things up and causing a flood if huge plumbing isn’t used!

I forgot about that. I guess I should think about changing my Bog filter setups...... I used 1.5" I'll probably be ok, and the drain is at the top.