Is there a table for when a leakage becomes a "spray" instead of a flow incl. pressure ?

[RedSnake]

Is there any table for the correlation between pressure, pipe/hose thickness and leakage opening when a leakage becomes a spray and not a flow?
I got this mission from my boss's, boss, boss to describe the electrical functionality between our machine parts and which pumps can be turned of without great consequences to avoid a "imaginary" spray of hydraulic oil at the same time as when there is a fire.
And how much work it will be to do this.
I ain't supposed to do a risk analyzes of the hydraulic system for this scenario but just a general one for what can be turned off and in which order to avoid other consequences.
I thought that I would at least try to see which pump systems have this risk.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[RedSnake]

I think that this "fire detectors" are using infrared light or something, they are made for detecting "smoke" but they do react to oil or water mist or vapor too even though it isn't there main purpose.

This thing with high pipe pressure due to thermal expansion, I would claim it will happen with or without pumps running all the pipes are still filled with oil.
With pumps in no flow no pressure or on a relief valve, if we take the main pumps as a example the pressure is 0 bar the maximum working pressure for the system is 315 bar and max before release valvs opens 325 bars and then there is some margin on that too on the mechanical strength of the pipes.
I am not sure how much expansion there will be and what that would render in bars.

If a fire would be allowed to burn so long that this expansion would happen there will not be much to save anymore, being a bit ironic now...

The yellow part at the topp is the hydraulic tank 6 m³ oil, that is 7 meters above floor level, then there is 3 meters in the celler too.

Just to give you a better picture this is the main pump system on the smallest machine on top of the tank.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[1503-44]

What's to be left to saved is not a consideration of the pipe code's (B31.x) requirement that all shut-in segments should be protected. If you have no restriction of thermal expansion in any pipe segment during a fire, or if such expansion reaches your existing pressure relief valve, then further relief is not necessary.

Expansion pressure can be found from a temperature-density table, or a known thermal expansion coefficient and the bulk modulus of the oil.

 

[RedSnake]

You are surly right.

But this machines are built according to the machine standard at the time and fulfills all requirements of the law today.
And we are not required to upgrade them if new laws are made since most of them are not retroactive.
This machines have the highest security level required for personal safety, not that this is a question about personal safety since all people should evacuate at a fire alarm.
But it makes this request more difficult to achieve, since turning of pumps in an "unplanned/uncontrolled way" makes the machines more unsafe for people.
And could render super high costs too, if robots and feeders are under the ram when the pumps are turned off then the ram will not be able to return to it's waiting position and will sink down and crush what's inside and might even destroy the tool, they are not cheap.
A bad stopp like that can cost a couple of millions and days of stop time at each alarm with or without any real fire.

This is actually just a recommendation.
To shut the pumps down so it will not feed a fire.
They claim it can't be put out otherwise.
Which I know is not true since we had a fire like that in the new line when it was new, bad construction and quality of equipment in that case.

If I would do this manually I would put the automation in cykel stopp and everything would stay outside the machines and then I would lock the ram, it lock mechanically and the main pumps are turned off then I still would have 5 other pumps running.
If I then turn the maneuver off I would still have two pumps running, the cooling pump it will run until the oil is + 35 C it might even be counter productive turning that one off depending on where the fire are.
And the return oil pump is still running when needed turning that off can end up with 6m³ oil on the floor down in the basement, since it can't pump leakage oil back up to the tank, maybe not either the best scenario.

Locking the rams automatically can only be done if the outer safety perimeter of the line is intact which is not always the case, so that would not achieve what they are asking for more then 2 times out of 3 maybe.

We can fly to the moon so of course this can be done, if must.
But what my boss³ wants to figure out is if we get the value for money doing this or if the money is better spent on better fire detection and extinguishing systems.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[1503-44]

Right, i'm sure it was built to codes in force at the time. Its just that doing so, even building to code in effect today, does not eliminate risk and that is what you are evaluating. If you think there is risk involved, list it. Give the why, rank the how much and how to mitigate it and put them all in the suggestion box.

 

[RedSnake]

I was thinking of using the risk evaluating tool used for machines safety and people just exchanging people with machine.
It might make it easier to see the wood for all the trees as we say.
Right now I not even sure in which end I should start pulling.
Tanks for the advice 1503-44.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[1503-44]

Careful. Machines don't run towards a fire to watch what happens, etc.