Alternate 3" pistion valve design

[samiam0295]

Hi, I'm new to the forum, but I have made a few spud guns before. Most of the valves designs I see on this site and others use a sleeve inside of a PVC tee. I thought up this design and will be building and testing in the next week. My design bores out the "Lip" inside of the PVC tee so that a 3" piston can be used that freely slides within the tee. Any input would be appreciated. Thanks.

[jackssmirkingrevenge]

Welcome to the forum

Here's how I would make it, a lighter piston opens quicker, puts less stress on the bumper and you gain some barrel length too. Of course it would depend on your barrel diameter because you might cause a flow restriction if the barrel is too wide.

[MrCrowley]

I imagine the lip has some structural function, removing it might not be a good idea.

[mattyzip77]

Its done like this in a supah valve so I dont see why not, also I know alot of people who have done this with a two inch tee..

[MrCrowley]

True, I've done it myself with a hole saw but I couldn't bring myself to use it as I'm scared of large diameter PVC enough as it is. The lip probably does only act as a stopper for pipe that is socketed in the tee but I assume they take it all (the presence of pipe in the tee sockets) in to account when they rate them.

[samiam0295]

Welcome to the forum

Here's how I would make it, a lighter piston opens quicker, puts less stress on the bumper and you gain some barrel length too. Of course it would depend on your barrel diameter because you might cause a flow restriction if the barrel is too wide.

The outlet pipe is 2" running right to a threaded adapter for the barrel, so 1/2 should be enough space around the barrel. I like your lighter piston design, as the acrylic is heavy. It is actually scraps of solid surface countertop (Corian). It smells very bad when drilling or sanding it. Unfortunately I will not have access to the drill press or lathe until friday , but I'll see what I can do until then!

[jackssmirkingrevenge]

Silly question, if you have access to a lathe why not machine a one-piece piston out of acetal or UHMWPE?

[samiam0295]

At this stage I am still prototyping, I will possible machine a one piece piston eventually. However, I have the acrylic and the pvc, and the pvc will fit so perfectly in the tee, it isnt worth the cost and effort to machine the piston at this point.

[jackssmirkingrevenge]

it isnt worth the cost and effort to machine the piston at this point.

If you're asking someone else to do it I can see your point, but if you're doing it yourself a decent cup shaped acetal piston shouldn't make more than a few minutes to turn.

[samiam0295]

until I have a final design, I see no reason to buy acetal stock to make a custom piston when I can do essentially the same thing with things I already have laying around. However, the final version would definitely benefit from a one piece machined piston.