Unsure of what sizes to use

[Frictionless]

Hello there,

I recently purchased a 48x30x14 rimless tank with an internal overflow box that has three 1-3/4" holes in the bottom glass and two 1-1/2" holes on either side of the overflow.

My question is for the bulkheads and return pieces; what sizes would I need to purchase?

When looking online the dealers state the bulkheads with just one number for each item. Is that the total size or is that built to hold a certain sized pipe? So 1" Thread/Thread bulkhead.

For the returns I want to use Lock-lines. I have figured out that I need the ball socket connector piece as well as the flexible tubes and end nozzle. Does the connector piece follow the same rules as the bulkheads in measurement?

I am sorry if I am confusing.

 

[mcgyvr]

The "primary" dimensions for bulkheads are for the size pipe they use..
In the specifications it will state a required hole size..

For example...
See here.. (and scroll down into the "full details")
http://www.bulkreefsupply.com/bulkhead-abs-slip-x-slip-1-7c63a554c36ea63c77723a472b7ca20f.html

Here is an example of the information provided..

1/2" ABS Bulkhead Slip X Slip Dimensions (see diagram)
A - 44mm/1.72"
B - 43mm/ 1.69"
C - 27mm/1.06"
Installation Hole Size - Use our 30mm Diamond Coated Glass Drill Bit for DIY installation

 

[Frictionless]

Ok, so I would need a 1" bulkhead then. Thanks!

Would I need a bulkhead for the holes in the side of my overflow? Then connect a lock-line connector piece to that.

 

[mcgyvr]

I'm not sure of exactly what your overflow box is/does but "probably" would be my answer but personally I don't use loc-line as it creates quite a restriction..