Yes pretty much.

To my knowledge, no single fitting exists with a larger female connection than male. I advise using a connector and putting a close-threaded nipple into the male side. For the hose barb you could round off the hex part with a grinder or a dremmel, but if that's not an option just use a bushing and ...

Found:

1" Brass Tee
All Rubber washers and sealing Gaskets

Made:

Piston (hot glue)

Not Found:

3/4" Hose Barb (with threads on the outside, and Not hexagonal)
1" to 3/4" reducer
3/4" Female to 1/2" Male
1" Female to 3/4" Male
1" Nipple (with smooth surface inside)

Hello wonderful people of Spudfiles,

I need help building my piston valve. I can't find the parts
except for a brass tee at my local Lowe's store, or anywhere!
Can anyone help me find and alternate way to build a piston valve,
using parts I can find at a Lowe's or Home Depot?

Thanks.

Hello wonderful people of Spudfiles,

I need help building my piston valve. I can't find the parts at my local Lowe's store, or anywhere! Can anyone help me find and alternate way to build a piston valve?

Thanks.

Hey man I'm interested...I can't seem to find the supplies at Lowe's to make one so I'm probably going to buy one from you...how many do you have left?