anyone ever used a grease gun for a hrrststic taste of at tank

[tackit]

That means you'll have to lay it on the side to test???

Man I hope not, back up plan, I'll just put a tee on top of the standpipe I run on the air output side of the tank, come off the bull of the tee with a nipple and ball valve to vent the air, and pipe the pump to the top of the tee instead of the side of the tank where the compressor tube threads into the tank.

[tackit]

Started to get the compressor tank ready for hydro testing. Starter relay electrical feed has been removed and the pressure switch electrical hae been removed from the pressure limit switch. Now I have to lay the tank on its side and fill it with water and hook the test pump to it when the BSPT to NPT adapter fittings arrive in a few days.

[tackit]

more pics

[bcguide]

Every pressure vessel should have a data plate on it listing
The woking pressure and an hydro static pressure. I believe the hydro pressure is the one you test to.
If you do a search for asme codes you can find what you need to do a pressure test. Link is to some info on testimg
https://www.engineersedge.com/pressu...ests_13917.htm

[tackit]

Every pressure vessel should have a data plate on it listing
The woking pressure and an hydro static pressure. I believe the hydro pressure is the one you test to.
If you do a search for asme codes you can find what you need to do a pressure test. Link is to some info on testimg
https://www.engineersedge.com/pressu...ests_13917.htm

Sorry, I didn't see your message sooner bcguide, thanks.

[tackit]

Getting closer to hydrostat testing of the air-compressor tank

The weather is starting to warm up so I readied the air-compressor to be laid over onto the wooden rack Friday when a couple of friends are coming over to help out.

I plumbed the tank for the 3/4" water hose connection, and a second pressure gauge going next the 1/2" airline nipple with the ball valve, the hydrostatic pump is going to connect to the tanks 1/2" airline nipple when all the air is out of the tank.

The new and better pump was only tested to 250 lbs because I used a couple of 150lb fittings I had on hand to test it out. I was surprised both gauges readings were so close.

[tackit]

more pics

[wildcatfan]

I've read through the whole thread and I offer the following for your and others safety.
If you cannot vent all air out the tank before pressing it up with water you will have trapped air/gas that IF there is an issue will cause a rupture with explosive release.
if there is no opening on the top of the tank then it should be laid down so that one of the plugged openings will be straight up to vent all air.
In my job we routinely hydrostatically test pipe, relief valves and pressure vessels for air, hydraulics, water and diesel fuel.
1 would offer the following. Fill the tank completely with water from a water hose, vent all air. then close the valve from the hose and use your tester to raise the pressure to what ever test pressure you chose.
Different codes require different test pressures, ASME and the Code Of Federal regulations (46 CFR part 54) both used to require 150% for new vessels. I think both changed to 130% several years ago.

that pressure should be based on the lowest rating of any part of the system, not just the rating of the tank.

If you have all of the air out of the tank you may be surprised that only one or 2 pumps on your tester will raise the pressure dramatically.

go slow, we routinely raise the pressure in increments say 50% then 75% then 100% and hold for 5 min or so then increase slowly from there until we reach final test pressure. hold there and check visually for leaks.


good luck

[tackit]

The tank is laying on its side with two nipples looking up to vent air out of the tank. The plan is to hook the water hose to the brass hose connector whitch will be installed now that the tank has been lowered onto the wooden rack.

[tackit]

I would think it would take a large volume of air inside a vessel to rupture it, not just a smallish bubble of air.

[ronsii]

Air just stores the energy, more air more energy waiting to be released.

[tackit]

Air just stores the energy, more air more energy waiting to be released.

So, if there isn't a large volume of air inside a vessel, there won't be enough energy stored to rupture a vessel Yes?

[ronsii]

It will still rupture but once the metal breaks it loses pressure fast if there is no *real* stored pressure to keep pushing the opening bigger... kinda like a big dam with a mile of water behind it 500 feet tall versus a dam of the same size and height that only has 1 inch of water behind it 500 feet tall... if that makes sense....

Maybe a better way to say it is... the air in the tank keep the pressure on the water to get out even after the metal fails and starts to let water out the air is keeping the pressure up to make the opening bigger....

[tackit]

It will still rupture but once the metal breaks it loses pressure fast if there is no *real* stored pressure to keep pushing the opening bigger... kinda like a big dam with a mile of water behind it 500 feet tall versus a dam of the same size and height that only has 1 inch of water behind it 500 feet tall... if that makes sense....

Maybe a better way to say it is... the air in the tank keep the pressure on the water to get out even after the metal fails and starts to let water out the air is keeping the pressure up to make the opening bigger....

I have to reason there would be so many deaths caused by small bubbles of trapped air in lines and vessels, OSHA would not allow hydrostatic testing except by certified engineering companies. I'll give OSHA a call and see what they have to say about testing with a small bubble of air in a vessel.

Thanks, ronsii

[tackit]

After doing a lot of reading I've come up with my own unscientific hydrostatic test formula.

MAWP =200 PSI X .90 = 180 PSI
180 X 1.3=234 PSI

The vessel will be tested at 234 PSI for 10 minutes with test gauge mounted at top of the vessel with water temp and vessel temp BOTH at 70 degrees F, which will test the vessel 30% over MAWP.

[tackit]

Weather is getting better so the bottom of the air vessel got painted with Rust Bullet and new rubber feet were put on the cart. .

I bought 225' of new 3/4" hose and a hose cart so when the temperature gets up in the 70's and stays there I can fill the vessel with water and hydrostatic test air storage vessel.

I re-piped the hose cart, the hose reel was designed for the hose to go over the top of the reel and screw on to the brass hose adapter in the tee, I added the 2 1/2"shoulder nipple, the close nipple, and the two 1/2" 90's, now the hose lays down on the drum and won't kink from going over the reel, I also bought new rubber feet for it and painted the cart and the rims and spokes with Rustolem clear coat.

The next update will be the test.

[tackit]

new hose

[tackit]

Today the compressor's tank was hydro tested at 84.7 degree F, First it was tested at 240 PSI for ten minutes.... and then at 270 PSI for ten minutes. I have a video but my computer won't download it on my email account, maybe when people go to bed the internet and computer will become fast enough to download the video off a smartphone to my email account, and then I can download it on my Photobucket account and get a link to post here..


The pictures show the gauges on the compressor tank and on the pump and the bottom of the tank not pizzing out water from a crack or hole in the bottom of the tank.

[forhire]

Tackit, I know I'm a little late to the party. I've been busy. Here is a link to my homemade hydrostatic tester I built a few years ago... just for fun.
https://weldingweb.com/showthread.ph...bottle-rockets

[tackit]

Tackit, I know I'm a little late to the party. I've been busy. Here is a link to my homemade hydrostatic tester I built a few years ago... just for fun.
https://weldingweb.com/showthread.ph...bottle-rockets

I always enjoy looking at your pics and videos, it's fun watching talented people with many skills invent and repair stuff.

Unfortunately my Chinese lathe's cross slide is so badly designed, slack can't be adjusted out of it. It's either so tight you can't turn the handle, or it's so loose settings are meaningless.

[forhire]

Good bit of testing tackit. If you watched my pop bottle hydrotests it demonstrates very clearly how uneventful a full rupture is without any air. It just kinda splits and is done. Even with a little trapped air I doubt it would be enough to really matter. Of course testing with a lot of air is a whole other matter. When we pre-charged the pop bottles with air and then pushed them to burst it was loud enough the neighbor called the cops on us.

I have always wanted to destructively test some disposable propane canisters but just haven't gotten around to it.

[tackit]

Good bit of testing tackit. If you watched my pop bottle hydrotests it demonstrates very clearly how uneventful a full rupture is without any air. It just kinda splits and is done. Even with a little trapped air I doubt it would be enough to really matter. Of course testing with a lot of air is a whole other matter. When we pre-charged the pop bottles with air and then pushed them to burst it was loud enough the neighbor called the cops on us.

I have always wanted to destructively test some disposable propane canisters but just haven't gotten around to it.

It would be cool to blow them up, I like the bottle rockets, I'm going to look into building a few just to see if I can do it,

[cwby]

A grease gun makes a pretty good pressure pump. Cut the plunger out & braze up the hole in the end of the tube, fill with oil & pump upside down. We used to pressure test wellheads with all the time. Put a pressure gauge & a valve on the end of the hose, about 5 strokes after filling the void with oil will get you a couple of thousand pounds depending on the volume. Unbelievable how much pressure a grease gun pump will provide. Most of the grease hoses are rated at 10,000 PSI...

[Sberry]

Got a relief so it cant over do it with pressure washer.

[tackit]

Got a relief so it cant over do it with pressure washer.

Cary is my Labeling correct?