SpudFiles

If you want to build a piston valve housed inside the T then the biggest problem is to find a fitting that'll house the piston and the piston itself...

It would be cool if there was a part that can do that, huh?
I think I found it

These things are called tap cartridges and you can probably get them in any hardware store. Here in poland they all have BSP threads so they can be directly threaded into a T

If you remove the pin( or whatever you call that metal clip) it slides freely in its housing

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Thats pretty sick, I've always wondered how people get compact metal piston valves. Wouldn't you have to cut off the back part of the piston thing though and are there threads behind it?

You can find tap cartridges that have threads there or tap the threads yourself... (notice the retaining nut)


Though who said you can't use mechanical actuation?

What is more, notice that the one in the pic above is the same type of fitting that I adapted as a compression fitting. You can find cartridges like these in larger sizes too. I even use them as free bushings.
(well if you think of it it's rather hard to find a bushing that goes directly from 1.75" to 1/4" or something like that).

so the intended use for these is "needle" type valves?

or am i not understanding

Well, if you think of it tap valves are technically speaking globe valves


But you can easily mod them so that there is no longer any need to turn the knob/handle to open it. The piston slides freely just like in the vid.

Anyway I think that the handle in the pic above might have been confusing. I posted it just to show the retaining nut (meaning an additional threaded port) that some of them have.

i see what you meant now. i have not yet had the chance to look for them at the store but i did take apart a valve that looks very similar to the diagram you just posted. the threads holding it to the body are very fine and other than epoxy i could not use it in a typical piston valve unless i epoxied it in.

i am gonna have to take anougher trip to the store to see what they have...

Interesting, is this going into an actual project or is it just a heads up?

Also, what's with the artsy black and white pictures

naah I've got enough QEVs for my needs... But yeah I've been considering building a piston valve out of it for some project

It's definitely not the holy grail of spudding but since I've been using this for so many things (ohh BTW it can be used as a detent too ) I concluded it is worth sharing...

Ohh I just realized I forgot to mention that you can mod complete valves too... sure, performance wise theses wouldn't be better than sprinkler valves but at least you can us higher pressures

You idea stealer you, I'm still yet to test the other option with these, better pull my finger out and get it posted.

Well observed though, it took my four hours to think up the other use.