How do I measure PVC pipe?

[Lancer1993]

So got some PVC fittings in Bunnings today to build a 'cyclone' dust bucket for my table saw, measured the vac pipe and got 40mm, checked on the shelf and the docket says 40mm but when I got home I thought they were a bit big so measured them and its about 48mm internal diameter.

https://www.bunnings.com.au/holman-40mm ... w_p3141346
https://www.bunnings.com.au/holman-40mm ... w_p3142059
https://www.bunnings.com.au/holman-40mm ... e_p4750172

This doesn't make it any better, but I guess 40mm is the internal size of the pipe?
So the amount of water or air they will flow down the pipe?
https://formufit.com/pages/pvc-101

So you need to know the wall thickness and thus the outside size, which is probably 48mm in my case?

So my question is how the hell do you measure PVC pipe like this when trying to match it up to what you need?

Might try 32mm as it should be a closer match to the size I need.

[bumblebee]

Have a chat to the team at Bunnings, they usually have tradesmen there in the building trade who can answer your questions

[lancerdarryl]

Pipe is measured by the outside diameter and joiners are measured by the inside diameter

[bumblebee]

Makes sense
The exhaust pipe.of 2.25inch is the external diameter

[Lancer1993]

I think you'll find PVC pipe is an internal measurement as the walls are thicker than exhaust pipe steel. Its also used as a way to measure water flow.

[benyamin]

It's a nominal diameter depending on the pressure rating. 40mm VAC pipe is a different diameter to 40mm Pressure Pipe. Pressure pipe also comes in several thicknesses depending on the class (proportional to the pressure rating). You might need to use a flexible hose with clamps...

[Lancer1993]

Ended up retuning the 40mm and got some 32mm, with a couple of layers of duct tape it would be a good fit with the vac hose. I got a couple of bend pieces and already have some 32mm pipe so will them to join the bits through the bucket lid, which I might reinforce with a layer of plyboard. I need it so I can easily remove the vac hose when needed.

This is a test first cyclone bucket to make sure it works with what I have. Might knock it together later this week.

Anyone made something like this for a workshop dust collector?

[bumblebee]

Nope