Check out this kit shown on the forum's sponser web page
http://www.sprinklerwarehouse.com/SW9000-Hose-Bib-Kit-3-4-FHT-x-3-4-700-OD-p/sw9000.htm. If you scroll down a little, they have a great diagram that shows you all the parts. Many times, these things have to be connectted together in a particular order because different types of threading systems are used. I don't recall the exact names, but you might as well say that there is a standard for 'hose bibb' threads and a standard for general plumbing. With drip irrigation components, a mixture is used. Obviously something must be able to connect to your hose bibb, but then other coponents (like filters from what I've seen) will switch to threads used for general plumbing.
OK, after some quick research, I've realized that when one of these fittings says 'HT', that means Hose Threaded, while 'PT' means Plumbing Threaded. So
MHT = Male Hose Threaded,
FHT = Female Hose Threaded,
MPT = Male Plumbing Threaded,
FPT = Female Plumbing Threaded.
I also ran across the DIG web site, and they do have various components with different types of theads (i.e. different filters DIG sells have different types of threads). After a brief search, I was unable to find the part numbers referenced. So you'll have to do some more research on your own unless someone else posts with more specific information on the listed part numbers. But if you are starting from either a garden hose (or hose bibb), then that is a MHT. You'll have to start with some component that has FTH. From there, you just have to make sure all the components that you want to connect have the right combination of MHT, FHT, MPT, and FPT so that it can all be put together. (And for those out there that might be plumbing sex chalanged, you can only connect a MTH end to a FTM and a MPT end to a FPT end. A component listed as say FTH x MPT means the input side has a female hose thread while the output side has a male pipe thread.)
This post has been edited 1 times, last edit by "HooKooDooKu" (May 29th 2008, 9:19pm)