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Help with a QEV
Posted: Tue Aug 07, 2012 5:21 am
by AircannonSweden
I made this QEV yesterday and I can't get this sealing leak-free...what can i use for material? The piston is kinda big but it is still under construction
Piston and housing
"sealing"

Posted: Tue Aug 07, 2012 5:40 am
by MrCrowley
Is the piston even larger in diameter than the seat?
Posted: Tue Aug 07, 2012 5:44 am
by jackssmirkingrevenge
By "piston" do you mean half-digested piece of rubber superglued to a capacitor

Posted: Tue Aug 07, 2012 5:58 am
by AircannonSweden
MrCrowley: The piston fits perfect in the housing,when i push the piston forward it is air-tight but when i fill a tank with air(3 PSI or something)it will leak...Well,i should see if a find another material
jackssmirkingrevenge: Haha yes

i have made one more piston that is much shorter,i have taken out that material in the capacitor and filled it with hot-glue insted...I going to Stockholm today and i maybe found something there

Posted: Tue Aug 07, 2012 6:01 am
by MrCrowley
3PSI isn't enough, try 30.
Posted: Tue Aug 07, 2012 6:16 am
by jonesy42
You can buy QEV's on ebay for less than $15! (search quick exhaust valves).
I don't know why people bother "making" qev valves when
they are fairly cheap to buy?....,But thats in my opinion of course,
good luck anyway

Posted: Tue Aug 07, 2012 8:06 am
by Crna Legija
jonesy42 wrote:You can buy QEV's on ebay for less than $15! (search quick exhaust valves).
I don't know why people bother "making" qev valves when
they are fairly cheap to buy?....,But thats in my opinion of course,
good luck anyway

homemade one IMO preform better at least well made ones.
Posted: Tue Aug 07, 2012 8:40 am
by AircannonSweden
MrCrowley: Thank you,it worked with higher preassure
jonesy42: I have already built a cannon with a QEV from ebay

Posted: Tue Aug 07, 2012 3:03 pm
by Mr.Tallahassee
jonesy42 wrote:You can buy QEV's on ebay for less than $15! (search quick exhaust valves).
I don't know why people bother "making" qev valves when
they are fairly cheap to buy?....,But thats in my opinion of course,
good luck anyway

Good luck finding a QEV with porting larger than an inch for less than an arm and a leg.

Posted: Tue Aug 07, 2012 7:20 pm
by mattyzip77
Do you go on e bay? I just got two 1 1/2 inch pulse valves for 30 dollars shipped. I have never seen a qev bigger than 3/4 of an inch. After that size they are called diaphragm valves.
Posted: Tue Aug 07, 2012 8:25 pm
by Mr.Tallahassee
mattyzip77 wrote:Do you go on e bay? I just got two 1 1/2 inch pulse valves for 30 dollars shipped. I have never seen a qev bigger than 3/4 of an inch. After that size they are called diaphragm valves.
A diaphragm valve is not the same as a piston valve. Apples and oranges cannot be compared. They are similar in principal but they aren't the same. What I'm saying is that I can go buy steel pipe and fittings and make a 2'' ported piston valve for less than the cost of a commercial 2'' valve that also performs better. Why buy something and make do with it when you can build a better one the way
you want? The latter just makes more sense to me.
Posted: Tue Aug 07, 2012 8:35 pm
by dewey-1
mattyzip77 wrote:Do you go on e bay? I just got two 1 1/2 inch pulse valves for 30 dollars shipped. I have never seen a qev bigger than 3/4 of an inch. After that size they are called diaphragm valves.
Mead make a 1 inch.
Very expensive though.
http://www.mead-usa.com/products/detail ... =46&type=3
Posted: Tue Aug 07, 2012 8:38 pm
by PVC Arsenal 17
jackssmirkingrevenge wrote:By "piston" do you mean half-digested piece of rubber superglued to a capacitor

That is priceless. Clever job OP
Posted: Tue Aug 07, 2012 9:56 pm
by mattyzip77
dewey-1 wrote:mattyzip77 wrote:Do you go on e bay? I just got two 1 1/2 inch pulse valves for 30 dollars shipped. I have never seen a qev bigger than 3/4 of an inch. After that size they are called diaphragm valves.
Mead make a 1 inch.
Very expensive though.
http://www.mead-usa.com/products/detail ... =46&type=3
Dewey your always making a liar out of me...

Posted: Sun Aug 12, 2012 10:38 am
by AircannonSweden