Others Pressure testing low pressure fittings

[abstruse]

I have long wondered what the absolute burst pressures are for various fittings rated for low pressure, so I did a test involving a hydraulic pump and a series of fittings connected together (see picture).

Most of these fittings are brass, and probably rated at 200 psi or less.

My hydraulic gauge only went up to 10,000 psi. At that pressure, and leaving it for a while, I was not able to get any fittings to fail.

There wast virtually no air in the fittings, only hydraulic fluid, so if there were a failure, it wouldn’t be dangerous.

I really expected some of the fittings to fail, so I increased the pressure gradually over a period of hours. I was very surprised to find that at 10,000 psi. there were no leaks and no failures. I left this cluster fittings at 10,000 psi for maybe 10 minutes.

Although I am somewhat mystified by this, it gives me a lot more flexibility in using so-called “low pressure” fittings for the high air pressure used with PCP rifles.

Am I missing anything?

 

[Franklink]

....a series of fittings connected together (see picture).

Most of these fittings are brass, and probably rated at 200 psi or less.

My hydraulic gauge only went up to 10,000 psi. At that pressure, and leaving it for a while, I was not able to get any fittings to fail.
....I left this cluster fittings at 10,000 psi for maybe 10 minutes.

.........
Am I missing anything?

To answer your question.....body parts. What you're going to be missing is body parts. You got lucky.

 

[MountainSportAirguns]

This is a horrible idea and not something to mess around with. The big difference is the wall thickness and material, quality hpa fittings aren't brass. Brass is soft and the slightest hit onto a hard surface will crack and bust off. A reason high pressure fittings are more expensive, anything less is a ticking time bomb.

 

[abstruse]

Thanks for your concern. I have sent engaged in significant conversations with Chat GPT and have learned a great deal more about the subject. I may continue the project with many requirements.

Since there was virtually no air in the system, only hydraulic fluid, any failure of the pipes would not result in catastrophic bursting, rather simply a split or leak since oil is virtually noncompressible.

Basically, what I had, was a simple snapshot of one situation. Much more work would need to be done to come up with a generalized understanding of the subject.

Onward!

 

[Billm]

You might want to ask chat gpt about “Skin injection injuries and hydraulic fluid leaks”. I was a mission commander on Navy P3 aircraft. My first checklist item upon takeoff was to lift the floor panel over the main hydraulic pump and lines and inspect the lines for leaks. Not dripping/seeping leaks but basically high pressure leaks. We did this because under pressure hydraulic fluid passing through a small opening can slice right through the adjacent hydraulic lines and cause a catastrophic aircraft failure = crash. There’s a difference between not being able to compress a liquid and whether or not a liquid can be under pressure. If you couldn’t put a liquid under pressure, water jet cutters and industrial pressure washers wouldn’t exist.

 

[Billm]

I understand that you won’t get an explosive catastrophic failure. But, I would imagine that your body parts won’t appreciate the difference between a cut from flying shrapnel and a hydraulic jet.

 

[pan60]

when I worked in the industry ALL of fittings were schedule 120 so conceder that.
I doubt what you are messing with is even schedule 80?
and if you are going to play with it at minimum set up a test vessel to protected yourself but I would not "F" with it these fitting are rated for the need use and its easy to look up the ratings for any schedule little giving it make up metal brass aluminum steal.
when yo are doing this you want something that is rated a great deal percentage wise about the working use so it working use is 4500 lbs you might be looking to test at five six or maybe ten times that. I would want at minimum three times somwere around 14,000 lbs
then the material the is chosen as fatigue concereartions how many cycles can it withsand can it take a drop on load theres is a LOT that goes into this.


persanaly there is no way ii would be doing this without a great deal on knowledge on the topic
and this takes me to AI

me and a few friends have done some experimenting with AI we ask the same question we ALL got the wrong answer or incopleat answers. the question was risk multiple times not was was a 100% correct answers going we waited one week and risk the question, and agian we got the wrong answer.

I have ZORO trust in something regurgitating someone else wrong crap post on the World Wide Web. that AI looking searching and regurgitating crap information.

if this is something you have an interest in go to the library and check out some book and do some homework.
: )

 

[MountainSportAirguns]

My only concern is someone reading this thinking its ok because it worked for the OP. Always use the proper fittings for HPA, it's worth the extra money.

 

[pan60]

My only concern is someone reading this thinking its ok because it worked for the OP. Always use the proper fittings for HPA, it's worth the extra money.

plus one!

 

[abstruse]

plus one!

Yes. I should’ve put a disclaimer or warning in my original post.

 

[SpindleB]

Yes, those of us old f**ts remember Mr. Wizard and his warning that was something like:
"Now kids, don't try this at home without help from your dad".

Which in my family was just a challenge to dad to see if he could get it to blow up.

 

[Powermonger1]

Thanks for your concern. I have sent engaged in significant conversations with Chat GPT and have learned a great deal more about the subject. I may continue the project with many requirements.

Since there was virtually no air in the system, only hydraulic fluid, any failure of the pipes would not result in catastrophic bursting, rather simply a split or leak since oil is virtually noncompressible.

Basically, what I had, was a simple snapshot of one situation. Much more work would need to be done to come up with a generalized understanding of the subject.

Onward!

Not good if you do! I did the tests in the early 80s and got them to blow at between 350 and 750 psi. I did this in a 3/8 wall heavy duty pipe and covered with moving blankets. Don’t take the chances the pieces can go flying till stopped by something! Moving blanket! Not worth an eye or jugular vein! Please don’t try this or use them in replacement. You can get hp fittings from swadgelok that go to 10000-15000 psi.
What I used to build the first bulk filled regulated unit for the Saxby and Palmer cartridges. Was the first regulated airguns in the early 80s.

 

[Powermonger1]

I used the series 83 for the Saxby

This gives you an idea of the space industry’s guidelines

 

[Dogowski]

I have long wondered what the absolute burst pressures are for various fittings rated for low pressure, so I did a test involving a hydraulic pump and a series of fittings connected together (see picture).

Most of these fittings are brass, and probably rated at 200 psi or less.

My hydraulic gauge only went up to 10,000 psi. At that pressure, and leaving it for a while, I was not able to get any fittings to fail.

There wast virtually no air in the fittings, only hydraulic fluid, so if there were a failure, it wouldn’t be dangerous.

I really expected some of the fittings to fail, so I increased the pressure gradually over a period of hours. I was very surprised to find that at 10,000 psi. there were no leaks and no failures. I left this cluster fittings at 10,000 psi for maybe 10 minutes.

Although I am somewhat mystified by this, it gives me a lot more flexibility in using so-called “low pressure” fittings for the high air pressure used with PCP rifles.

Am I missing anything?

Let's Not do this please. I'd like to see you around for a long time!

 

[Powermonger1]

Ok, let’s put it this way. I’ve worked in heavy equipment and trucking. Even hydraulic fluids can bow apart fittings at an accelerated rate. I’ve seen stuff that would blow you mind. Do me a favor and use the information or order a catalog and you can find all the safety factors in it. I’ve seen chunks of brass flying across a yard from a 980C Cat lifting a bucket of dirt and we are not talking high pressure here. 2000-2200 max with a load on. You a 1693 cat engine pushing a hydraulic pump , not good when s**t fails!

 

[abstruse]

I really appreciate all of your cautionary messages. For a practical point of view, I don’t think I have a problem here, because I have been convinced to use nothing but high pressure rated fittings for my project. Thanx!

It would be fun to do a progressive, high-pressure test, but for the time being, I’m going to put that in my large stack of things that would be fun to do at some point.

Thanx again