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Piston Valve Build Help.

Posted: Sat Jan 29, 2011 11:03 pm
by D&J
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.

Posted: Sat Jan 29, 2011 11:07 pm
by saefroch
Well since your question is almost completely ambiguous, let's start here:
What can you NOT find?

Posted: Sat Jan 29, 2011 11:21 pm
by D&J
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)

Posted: Sat Jan 29, 2011 11:32 pm
by saefroch
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 file/sand down the inside face to make a good seal.

Are you copying a design you found somewhere? There are many ways to construct a piston valve, you don't need to use exactly the fittings stated in a tutorial or somebody else's design by any means. (Edited for proofreading fail)

The way I recommend constructing a piston valve is like I did with both of the builds in my sig. Bushing for the sealing surface in the valve, then a tee, then a nipple to house the piston, then a straight connector, then a bushing as the piston stop. This way the piston doesn't try to wedge itself into a reducer, which has a nice conical shape on the inside.

Posted: Sat Jan 29, 2011 11:33 pm
by qwert123
Ha! I bet you found the tutorial on YouTube or instructables i have tried to find the hosebarb for weeks. I would recommend useing a PVC adapter and using a file to remove the ring inside so you can slide PVC (barrel) through. Trust me that is the best tutorial for a piston vale except for tha one part. And also don't post the same topic twice or Mr. Crrowly will be on you like super glue. I know from experice! :roll:

Posted: Sat Jan 29, 2011 11:52 pm
by jrrdw
Well the hardware store in your area needs organization skills because every hardware store in my area keeps all the brass fittings in one isle!

@qwert123, Mr. who? "Crrowly", try MrCrowley.

Posted: Sat Jan 29, 2011 11:53 pm
by D&J
saefroch wrote: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 file/sand down the inside face to make a good seal.

Are you copying a design you found somewhere? There are many ways to construct a piston valve, you don't need to use exactly the fittings stated in a tutorial or somebody else's design by any means. (Edited for proofreading fail)

The way I recommend constructing a piston valve is like I did with both of the builds in my sig. Bushing for the sealing surface in the valve, then a tee, then a nipple to house the piston, then a straight connector, then a bushing as the piston stop. This way the piston doesn't try to wedge itself into a reducer, which has a nice conical shape on the inside.
Yes I am trying to follow someone design, and its not working at all. Can u email me pictures and/or a parts list for your build design so I can either build it to your specs or model mine after it? (jdlservice@gmail.com)

P.S. I'm new to air guns so yeah I need all the help I can get.

Thanks.

Posted: Sun Jan 30, 2011 12:32 am
by daniel0663
I'm no expert on air guns, but......
Instead of a "Hose barb" you could get a 1" - 3/4" Bushing, and Thread a 3/4" THREADED nipple as a sealing face.
You would have a much larger air port, than a hose barb.

Posted: Sun Jan 30, 2011 1:16 am
by Gaderelguitarist
I always made mine with pvc fittings. I guess that'd be fine if you're using compressor pressures though.

If you can't find what you need in either of those stores why not try Mcmaster? They've never let me down when it comes to specialty materials.

Posted: Sun Jan 30, 2011 2:12 am
by Gippeto
Try a slightly different design?

More info...and pics...can be found here;

http://www.spudfiles.com/forums/piston- ... 13478.html

Piston could be made from virtually anything round and nearly the correct diameter. o-rings are not absolutely neccessary for it to work either. Can be simplified to suite available materials.

Posted: Sun Jan 30, 2011 8:33 am
by saefroch
D&J: The pictures are in the links in my sig. Just click on them and look around. Any further questions about them, PM me.

Posted: Sun Jan 30, 2011 9:34 am
by qwert123
Checked mcmaster Carr to they don't carry such a part. I believe sliding PVC through a adaptor so it is inside the tee, I am doing that. I already have the parts, just need to glue them together.

Posted: Sun Jan 30, 2011 12:37 pm
by qwert123
@D&J i beive this is the video you saw:
http://www.youtube.com/watch?v=vmxaI3_SJCg

Posted: Sun Jan 30, 2011 9:18 pm
by D&J
Yes pretty much. :(

Posted: Sun Jan 30, 2011 9:31 pm
by Technician1002
The hose barb can sometimes be found in the irrigation section. They are used for attaching black PE pipe for sprinkler systems. Often you won't find them in the general plumbing section as they don't meet code in many places for domestic potable water. If you check the garden section, most of those hose barbs are female threaded to screw onto a garden fawcet. Those are the wrong ones. You want the ones for underground sprinkler systems.

To find the smooth inside nipple, look for the brass pipe and fittings. The iron ones are the wrong ones. The small machined brass nipples are smooth inside. They cost more so some hardware stores don't carry them due to the higher prices and slow sales.

Find a hardware store that has a full line of brass fittings and you should be able to find your parts.

Big box stores with only plastic, copper, and iron is not what you want.