gbcannon.com
disclaimer

golf ball valve
valve image

This page is still under construction

description

This valve is a multifunction piston valve in a tee.

features

The name golf ball valve refers to the 1.7" porting of the valve which is about the size of a golf ball. This particular version is built in a 2" slip x slip x FPT tee. It has a section of 2" pipe for the piston to slide in and a 2" female NPT adapter for piston servicing. The front has a 1.5" bushing with 1.5" SDR21 running through it and partially into the tee. The SDR21 also extends into another bushing which is used to connect another 2" female NPT adapter. The overall size of this valve works out great for powerful handheld launchers without being too bulky. The 2" threaded adapters allow for interchangeable chambers and barrels.

The piston is o-ringed and has a check valve built into it so the valve can be actuated with pretty much any valve. Even depressing the pin on the schrader valve can actuate the piston. The sprinkler valve for exhaust is probably a little bit overkill since the opening speed of this valve isn't very dependent on the pilot valve size, but it will give it a little bit of a performance boost and helps reduce the delay between pulling the trigger and the gun actually firing. The configuration allows it to not feel too bulky, so I decided it would be worth the little boost. By switching out the piston, the valve can be turned into a chamber sealing valve, but I really don't ever change it because the barrel sealing configuration has several advantages.

GGDT file

gallery

front.jpginternals.jpgnewpiston.jpgpilotopen.jpgpiston.jpgpistonclosed.jpgpistonopen.jpgpistonrear.jpgrearangle.jpgrightside.jpgsprinkmod.jpgsprinkmod2.jpg

background

I started designing this valve with the goal of creating a valve with as much flow as possible in a two inch tee. Tee valves weren't very common in the community at the time, and there weren't a lot of examples to look at. The first design I used was an o-ringed piston that sealed in a two inch pipe on each side of the tee. It was a design that I had never seen used before, and I saw no reason why it wouldn't work. After building the valve I was disappointed to find that, although it did release the air, it seemed to only crack open. After consulting with the guys on the Spudtech forum and a lot of thinking about what makes piston valves work, I was able to gain some insight into why it wasn't working. The knowledge gained from this failure was very helpful in developing my comprehensive understanding of how piston valves work and some of their key design aspects.

After gaining the insight into piston valve design through the first failure, I went through several more construction failures that provided useful experience in piston valve construction.

status/outlook

This valve is still used fairly frequently. I use this valve both for high power shots and for smaller launchers when I want more power than my golf ball cannon.

history

12/03 - Original valve created
8/08 - Photos taken and this page partially created.

related links

piston valve concepts
Spudtech thread
Spudfiles thread