Super Soaker Central

This article explains all about the differences between PVC pipe in America and Australia. The information in this goes for both Australia and New Zealand, however New Zealanders will need to find different plumbing shops than what I've talked about here.

First off, the size compatibility. American and Australian PVC pipe have the same outside diameter. This means that American pipe can fit inside Australian fittings and vice-versa. Here's a list of the sizes you can get in Australia and NZ, and their American equivalent.

• 15mm = 1/2"
• 20mm = 3/4"
• 25mm = 1"
• 32mm = 1 1/4"
• 40mm = 1 1/2"
• 50mm = 2"
• 65mm is the only incompatible size.
• 80mm = 3"
• 100mm = 4"
• 150mm = 6"
• The list goes on.

The only difference between Australian pipe and American pipe is the wall thickness. This affects the internal diameter and the pressure rating of the pipe.

There are 5 different 'classes' of PVC pipe in Australia. Each class corresponds to the pressure rating of the pipe, in bar.

• PN6 = 87psi
• PN9 = 131psi
• PN12 = 174psi
• PN15 = 218psi
• PN18 = 261psi

IMPORTANT: When building a homemade or water balloon launcher, make sure you are using pressure rated pipe. Just check for the PN# on the side of the pipe. If you can't find it, don't use it. I would recommend using at least PN12 pipe. Also, never go above half of the pressure rating of the pipe as PVC wasn't designed to store compressed air.

All of the pipe sizes come in most of those pressure ratings. However, what you'll generally find in the shop is that as the size goes up, the pressure rating goes down. For example, in the shop I go to, you can only get 50mm pipe in PN12, but you can get 15mm pipe in PN18. This isn't true for all shops though, some will have the larger sizes in the higher pressure ratings too. If you were really determined you could order your own length, and choose your pressure rating and size, however at 6 metres (20 feet) long they're expensive and wasteful.

One thing that you do need to be careful of though: the thread incompatibility. Australia, New Zealand and the UK use the BSP thread standard, while America uses NPT. They are only small differences, but they generally won't work together. The exception to this rule however: 1/2" and 3/4" BSP and NPT threads ARE compatible. You need to watch for this if, for example, you ordered a spud gun valve over the internet. This happened to me, but I managed to catch this before I ordered it. I asked the guy if he could send me over the necessary NPT valve adapters (just an NPT thread on one side, and a pipe socket on the other) and he was more than happy to.

In Australia and NZ when buying PVC pipe, you simply ask for how much you need and they'll cut it for you and charge accordingly. You aren't required to buy whole lengths. Generally it's a good idea to get a few centimeters extra though, as the people in the shop usually cut it with a hacksaw which gives a pretty bad cut, and you need as straight a cut as possible when making a homemade.

Finally, you need a good place to find your pipe. The easiest place to go is Bunnings, they have an ok selection of fittings and pipe, however their range only goes up to 50mm. Also they're a bit more expensive than plumbing shops for that sort of thing. A better place to go would be Reece, or Tradelink. They have a much better selection than Bunnings, and will probably be cheaper. I've been to Reece before and they have a huge range of pipe and fittings, however some of their stuff can be expensive. Your last option is to just try and find a local plumbing supply shop. It's quite good when you get to know the people there, and if you tell them what you're doing they're usually really interested. You might even get discounts!

So there you have it. Hopefully that makes it easier for Kiwis and Aussies who are looking to build their own homemades. Good luck!