Hole Size for 2 inch bulk head

[chome360]

Hi All,

Having a custom tank built. Planning to go with schedule 80 2-in bulkheads for the drains. Manufacturer has 75 mm hole planned for the external overflow. I haven't picked out my plumbing yet, so now final decision on fittings. Question is, is that the ideal hole size for 2-in fittings in general? The BRS chart has the minimum hole size of 81 mm, but finding other sources that say 72 mm to 75 mm. For example this one:

Schedule 80 Bulkhead Slip to Slip

Professional Aquarium Bulkhead Style: Slip to Slip Available in: 1/2in, 3/4in, 1in, 1.25in, 1.5in and 2in

store.coralvue.com

Not sure what to do...

 

[Submerge]

You need to match the hole size to the actual manufacturer recommendation which will vary slightly based on source. So for the ones you linked 75 is perfect.

If you go with another product it might vary slightly.

this conversation is changing units from 2” to 75mm. European pipe sizes are not compatible with us sizes. Given all this you will never get a “best size” you are looking for.

The bulkhead needs to slip cleanly thru the hole with no binding. Beyond that the larger the gap gets the worse it is for sealing.

 

[chome360]

You need to match the hole size to the actual manufacturer recommendation which will vary slightly based on source. So for the ones you linked 75 is perfect.

If you go with another product it might vary slightly.

this conversation is changing units from 2” to 75mm. European pipe sizes are not compatible with us sizes. Given all this you will never get a “best size” you are looking for.

The bulkhead needs to slip cleanly thru the hole with no binding. Beyond that the larger the gap gets the worse it is for sealing.

Thank you! Hmm, so sounds like I need to make plumbing manufacturer decisions before deciding on hole size? Any recommendations on the most common "high quality" schedule 80 2-inch bulkheads? Hayward the go-to?

 

[Kooma]

Grab a BRS bulkhead and reference their charts. You dont need to decide on the whole plumbing, but do need to finalize your hole sizes, based on flow and head/friction losses and tank size. Be sure to add an emergency drain to the systems overflow. (one siphon, 1 secondary, one emergency)

BRS says 72mm min.

Bulkhead ABS Slip x Slip

Bulkheads create a secure, watertight connection through the wall of an aquarium or sump, allowing plumbing to safely move water in or out of the system. These low-profile, reef-safe bulkheads are made from durable black ABS plastic and feature a slightly thicker construction than many standard...

www.bulkreefsupply.com

 

[chome360]

Grab a BRS bulkhead and reference their charts. You dont need to decide on the whole plumbing, but do need to finalize your hole sizes, based on flow and head/friction losses and tank size. Be sure to add an emergency drain to the systems overflow. (one siphon, 1 secondary, one emergency)

BRS says 72mm min.

Bulkhead ABS Slip x Slip

Bulkheads create a secure, watertight connection through the wall of an aquarium or sump, allowing plumbing to safely move water in or out of the system. These low-profile, reef-safe bulkheads are made from durable black ABS plastic and feature a slightly thicker construction than many standard...

www.bulkreefsupply.com

Thanks. I did check out the BRS chart, it says for 2 inch schedule 80 I need a hole size of between 81 mm and 103 mm. Problem is, unless I'm missing it, they don't sell any schedule 80 bulk heads... So I'm nervous about going with their recommended specs when I don't have a specific part to match.

The 72 mm minimum you saw on their site is for ABS.

Definitely going with the 3 holes, main, overflow and emergency.

 

[Kooma]

Thanks. I did check out the BRS chart, it says for 2 inch schedule 80 I need a hole size of between 81 mm and 103 mm. Problem is, unless I'm missing it, they don't sell any schedule 80 bulk heads... So I'm nervous about going with their recommended specs when I don't have a specific part to match.

The 72 mm minimum you saw on their site is for ABS.

Definitely going with the 3 holes, main, overflow and emergency.

Thinking about it now I dont think I have ever usd anything but ABS bulkheads. I would find the parts you want, order them, measure them and then provide those details to the builder.

 

[chome360]

Is there a "go to" brand for this stuff in general? Trying to narrow down my bulkhead choice. I've gotten down to a few choices, Hayward, Reef Octopus and Savko. All three require slightly different hole size. Hard to choose which one when I don't see any clear and mayonnaise or disadvantage to going with one over the other...