High pressure metal piston valve seat

Lockednloaded · Sun Sep 04, 2011 9:10 pm

I'm not sure if this belongs in the how-to section, but I can make a how to on the full valve if y'all would like. This is just a standard part that can be found at any lowes or homedepot. Its a 3/4" male NPT x 3/4" female GHT adaptor, but the 3/4" male end had 1/2" inner threads. A picture's worth a thousand words, so I'll leave you with 6

Gun Freak · Sun Sep 04, 2011 9:15 pm

Nice find! One thing holding me back on a metal piston valve has always been the seat. (and the cost) Another monster, soon to come, courtesy of LnL.

Lockednloaded · Sun Sep 04, 2011 9:19 pm

Gun Freak wrote:Nice find! One thing holding me back on a metal piston valve has always been the seat. (and the cost) Another monster, soon to come, courtesy of LnL.

If that's all it took to get you to build a metal gun, I should've posted this a long time ago!

Seriously, this part makes metal valves so easy, it's the same part I used on my piston hybrid. And even though the female threads are GHT, NPT threads seal due to the gasket.

mattyzip77 · Sun Sep 04, 2011 10:05 pm

Dang, thats awesome!!! You cant make it any easier than that!! However I am most sure someone wont understand it, lol!!

Great find!!!!!

Technician1002 · Sun Sep 04, 2011 10:20 pm

For a better wider seat, instead of using a nipple, use a pipe cutter and cut the threaded end off a piece of pipe. That will give a wide seat that is less likely to cut the piston seal at high pressure. Once the pipe is cut, sand it smooth and flat on sandpaper on a flat surface. By carefull cutting of the pipe, you can adjust the extension into the T to the optimum length of about 1/3 the way in for best flow.

Lockednloaded · Sun Sep 04, 2011 10:34 pm

Technician1002 wrote:For a better wider seat, instead of using a nipple, use a pipe cutter and cut the threaded end off a piece of pipe. That will give a wide seat that is less likely to cut the piston seal at high pressure. Once the pipe is cut, sand it smooth and flat on sandpaper on a flat surface. By carefull cutting of the pipe, you can adjust the extension into the T to the optimum length of about 1/3 the way in for best flow.

I tried that, but it's too wide for the piston to seal on in my experience. Of course someone could make the sealing face wider. My rule of thumb is that you piston seat should be able to fit through your piston housing. I've never had trouble with sealing faces getting cut, this seat has held 400psi in my piston hybrid, and that was just the force holding it closed

ramses · Sun Sep 04, 2011 11:32 pm

Lockednloaded wrote:
Technician1002 wrote:For a better wider seat, instead of using a nipple, use a pipe cutter and cut the threaded end off a piece of pipe. That will give a wide seat that is less likely to cut the piston seal at high pressure. Once the pipe is cut, sand it smooth and flat on sandpaper on a flat surface. By carefull cutting of the pipe, you can adjust the extension into the T to the optimum length of about 1/3 the way in for best flow.
I tried that, but it's too wide for the piston to seal on in my experience. Of course someone could make the sealing face wider. My rule of thumb is that you piston seat should be able to fit through your piston housing. I've never had trouble with sealing faces getting cut, this seat has held 400psi in my piston hybrid, and that was just the force holding it closed

If the piston seat (OD) cannot fit through the piston housing, it is larger than the piston, and therefore the piston is not exposed to any pressure on the sealing side. Your rule of thumb, as I understand it at least, allows the absolute maximum seat diameter that could possibly work in an ideal situation.

jazzman56 · Mon Sep 05, 2011 5:51 am

This solves my problem, the bunnings i have doesn't sell any brass hose barbs so now i can build a valve with this sealing face. Thanks

Crna Legija · Mon Sep 05, 2011 7:03 am

jazzman56 wrote:This solves my problem, the bunnings i have doesn't sell any brass hose barbs so now i can build a valve with this sealing face. Thanks

As far as I know bunnings don't have them fittings(worked there for two years and might as well move in how much I go there lol).

But there 3/4''-1/2'' reducers can be used that way, that's how I did it lol.

also they do have brass hose barbs but they keep them in the irrigation aisle.

clemsonguy1125 · Mon Sep 05, 2011 10:30 am

Nice find, I wonder if they have one, 1/2 to 1/4

Lockednloaded · Mon Sep 05, 2011 12:02 pm

clemsonguy1125 wrote:Nice find, I wonder if they have one, 1/2 to 1/4

Probably not, I believe GHT threads only come in 3/4".

Gun Freak · Mon Sep 05, 2011 1:40 pm

I looked for one at my home depot today, they didn't have them. Was yours in the brass fittings section?

Lockednloaded · Mon Sep 05, 2011 2:12 pm

Here's the final valve:

Gun Freak, that's exactly where I found it, did you try asking someone who worked there about it?

Gun Freak · Mon Sep 05, 2011 2:27 pm

I'm done asking people who work at home depot, I know the plumbing department better than their employees.

A worker there was telling a lady about how you can't use PVC with CPVC because "the inside diameters won't match up"

Valve looks nice. I want to make one

jsefcik · Mon Sep 05, 2011 2:44 pm

Gun Freak wrote:I'm done asking people who work at home depot, I know the plumbing department better than their employees.

A worker there was telling a lady about how you can't use PVC with CPVC because "the inside diameters won't match up"

Valve looks nice. I want to make one

thats funny

High pressure metal piston valve seat

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