Pressure testing hydro

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Herwer
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Sat Nov 09, 2019 1:41 pm

Hi , i want to know more about hydro testing. I have some tanks and solid looking (for me) powder fire extinguishers and i want to see what pressure they can hold. So i need to fill water in that tank (all tank filled with water?) and then put in them (air) pressure that i want (i want use this tanks for 400 psi so to have confidence i need to put little more like 600 psi?) How it works , the tank with water will not blow up or what? If i will put water inside that tank it will start to corrode right? how to stop that?
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Moonbogg
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Sat Nov 09, 2019 5:54 pm

You can't fill with water and then pressurize it with air. If it fails it will explode. You have to fill it with water and then pressurize it with more water or grease from a grease gun. I'd suggest getting a nice large grease gun and modifying the seal inside so you can fill it with water and use it to pressurize. I used grease to pressurize and it worked, but it was a total mess and took a while to clean up.
Herwer
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Sun Nov 10, 2019 5:56 am

Can you send a photo what grease gun looks? something like this or this another?
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mrfoo
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Sun Nov 10, 2019 9:32 am

More like one of these, I'd have thought.
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hectmarr
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Sun Nov 10, 2019 9:41 am

mrfoo wrote:More like one of these, I'd have thought.
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The "forced" question: With the necessary modifications, do you think you can pump air with that? :roll:
Ideas don't make holes. The weapons yes! ;)
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D_Hall
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Sun Nov 10, 2019 11:55 am

OK, some thoughts here....

1 - Actually you *can* fill it with water and then pressurize with air but you absolutely have to do this one dead nuts correctly or things can go badly. Most folks haven't the know how or equipment to do it right and there are other techniques that are easy to do so unless you've got a very good reason to do it that way... Don't.

2 - The grease gun mentioned previously is a great way to do it at the hobby level, but I'll throw a suggestion in there. Do not use grease. It's a royal pain in the ass to clean up (as has been noted in the thread). Instead, use honey. It's thick enough to go through the pump correctly, is reasonably cheap and easy to get, and most importantly it's water soluble so clean up is simple.

3 - If you have a large tank, a pressure washer works great. Just replace the nozzle with a fitting that allows you to go to your tank and you're golden.
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farcticox1
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Sun Nov 10, 2019 12:26 pm

How much pressure can you get from a bottle jack ?
https://www.ebay.ca/itm/Pro-Lift-B-002D ... SwsvVdvyzX
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Moonbogg
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Sun Nov 10, 2019 2:03 pm

D_Hall wrote:OK, some thoughts here....

1 - Actually you *can* fill it with water and then pressurize with air but you absolutely have to do this one dead nuts correctly or things can go badly. Most folks haven't the know how or equipment to do it right and there are other techniques that are easy to do so unless you've got a very good reason to do it that way... Don't.

2 - The grease gun mentioned previously is a great way to do it at the hobby level, but I'll throw a suggestion in there. Do not use grease. It's a royal pain in the ass to clean up (as has been noted in the thread). Instead, use honey. It's thick enough to go through the pump correctly, is reasonably cheap and easy to get, and most importantly it's water soluble so clean up is simple.

3 - If you have a large tank, a pressure washer works great. Just replace the nozzle with a fitting that allows you to go to your tank and you're golden.
Holy crap the honey idea is brilliant, lol. Next time I need to do this. It would be tempting to just fill with water and use an HPA pump to add high pressure air to pressurize. That's easier, but my noobism in this area causes fear of creating a high pressure squirt-gun if the thing springs a leak and having it water-jet my eyes out :lol:
Next time I use honey in a grease gun. For anyone underestimating the pain in cleaning up 2 or 3 tubes of grease after dumping it out on the LAWN and trying to hose it away, don't.
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D_Hall
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Sun Nov 10, 2019 3:03 pm

OK, if you truly do just want to do it with water and air....

1 - Use an air system/hose that is WAY over built so that *if* your system fails, it is the chamber that does so and not your air hose.
2 - Include an orifice to restrict flow from your air hose so that only an itty bitty stream of water (like maybe 0.01" diameter) is allowed into your chamber (your air line is actually going to be full of water).
3 - Clamp or otherwise anchor the air fill hose such that in the event of a rupture it can't fly around.
4 - Pull a vacuum on your tank and all fittings/hose from your chamber to the air supply.
5 - Introduce water via a sealed system.

You should now have a tank full of water with absolutely zero air bubbles in it.

6 - Feel free to use air to pressurize.

See why it's easier to just use a grease gun?
Last edited by D_Hall on Mon Nov 11, 2019 12:05 am, edited 3 times in total.
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Herwer
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Sun Nov 10, 2019 4:17 pm

Ok . I have 0.8 liter HPA tank and i want to test 0.25 liter bottle to something around 500 psi. How can i do this? i have air hose with quick disconnects and i need to connect it to a valve that will be connected to tank with water? Something like this blowgun? or just normal kercher will do the trick?
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D_Hall
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Sun Nov 10, 2019 4:33 pm

If you have to ask... Yeah, go buy a grease gun and some honey.
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Moonbogg
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Sun Nov 10, 2019 9:22 pm

Yep. Do the honey method, my friend. Screw all that complicated stuff. Plumb some high pressure honey into that sucker and wash it off your lawn in 2 minutes = job done.

Also, I've heard it said you can reverse the cup seal inside the grease gun so it will seal with water. I tried that on a small, cheap grease gun during my own testing and the water still leaked like crazy so I just used the grease. Maybe a larger, better quality grease gun can be used with water this way, but if it fails, I think honey or something else very thick like honey (such as molasses) would actually do the job.
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jackssmirkingrevenge
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Thu Nov 14, 2019 7:47 am

D_Hall wrote:Instead, use honey.
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D_Hall wrote:Just replace the nozzle with a fitting that allows you to go to your tank and you're golden.
... especially if you're using honey and the thing explodes.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Herwer
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Tue Nov 19, 2019 12:26 pm

Yea i think I will use Karcher 190 bar pressure washer and connect it to tank. ( but i want to test 0.2 liter tank and the pressure washer will fill it to 190 bar in second how can i stop that?) and have you any idea how to clear water of that tank to not get rusted? Thanks for the help.
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