SpudFiles

Well I got a 400 psi pump and some metal pipe already, so I have $50 for the piston valve, elbows, tee, etc. etc.

So how can i use the schrader valve for the pilot? just poke on the thing inside?

Edit: I can use a ball valve? won't it fail from the pressure? I thought they were rated for 150 psi, but what do i know?

oh man, making a good piston that holds 400psi out of 50$ is going to be hard. theres always little things that you forget to calculate and those little things will add up.

dont use a schrader valve for the pilot. its too slow and those things are not rated for 400psi. just use a ball valve thats rated that high. pvc ball valves are rated for 150psi. brass/metal ball vavles are MUCH higher

Oh okay, and btw, i got $25 early for christmas(... ) so now the budget is $75! yay!

Schraders are fine at 400psi. I overpump a small chamber on a test cannon to 400psi with a shock pump every now and again when I feel like tinkering with it.

I'd be more concerned about how well a schrader could pilot the piston.

Can someone send me a link on a how to for a piston valve? I searched but i can't seem to find it... maybe I'm dyslexic

Yes, thanks a lot!

A how-to build one or how one works?

If you want how-to build one:
http://www.spudfiles.com/forums/how-to- ... 10381.html

If you want how one works, click Hotwired's link in the post above.


Edit
Ah you bet me to it

AlbinoSpud wrote:Well I got a 400 psi pump and some metal pipe already, so I have $50 for the piston valve, elbows, tee, etc. etc.

Even so, and with your now expanded budget, a restrictive budget will encourage you to cut corners on the construction, and with 400 psi involved, nothing less than the best is a good thing.

A QEV can handle 400PSI. I have 6 Detrol QEVs and they are fine at that pressure. They are ideal for high pressure valves as they open insanely fast.

A schrader CAN take 400PSI easily, and will work very well as a pilot valve, but as JSR said, you need your pilot volume to be minimal.

Ball valves can take 400 PSI+ as they are metal. Even if it says it's rated to 150PSI, as long as its metal it will be fine above 200PSI.

The ONLY type of sprinkler that is good at 200PSI + is the (expensive) brass sprinklers that are available from eBay.

well then i might have to make this a slightly long term project. But i don't think it will be that long because i get $25 a week. How much do you think this will cost?

No... I'm not saying you need to have a crazy budget, but what I mean is if you find you are short, increase the budget rather than cutting corners.

I'll just go to the hardware store this weekend and see how much the stuff costs. I have connections with the people there so maybe i can get discounts

Edit: maybe i shouldn't have bought Rock Band and just do this first


Edit Edit: Apparently i have epoxy because i found some in my shower (wtf???)

umm i dunno about a pvc barrel if it would explode... a pumpkin chunkin PVC barrel exploded once.. I'd just go with metal barrel to be safe

ABS would be cheaper than metal, and should be fine at 400 psi. I've used it in large diameters with heavy projectiles, 450 psi, and valve opening times of <1ms, without any failures.