erosion of metal as a result of fluid blasting 1

[keyen]

Hi,

Can anyone point me to references to determine the erosion rate of steel that is being blasted by a fluid spray. I'm trying to determine how thick to make a plate that will be used to contain a leak emanating from a high temp/high pressure source. I'm trying to solve a problem such as: if a 500 degree, 500 psi system began leaking from a 0.125" hole onto a 0.375" plate (12" away); how long before the plate was punctured?

thanks,
Dave

 

[BigInch]

I think you would make the hole larger well before you eroded the plate.

you must get smarter than the software you're using.

 

[LittleInch]

Depends far too much on the fluid - clean and particle free or not and the shape of the jet. Most leaks will tend to disperse the jet rather than concentrate it so the impact is much less.

This whole thing doesn't sound like a good idea to me.

Ps 500 degrees what? F or C? what fluid?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[hydtools]

Here is a military paper on the study of liquid impact erosion:

http://www.dtic.mil/dtic/tr/fulltext/u2/a080607.pdf

Ted

 

[BigInch]

Nice paper. Thanks for posting it.

However I still think the problem will be the hole. With the highest fluid velocities, pressure and temperature there, it will most certainly enlarge, one can only hope not explosively.

you must get smarter than the software you're using.

 

[dbill74]

Sounds like a college homework assignment. Why would you place a plate 12" from a leak?
Best solution is to shut the system down and fix the leak.

 

[keyen]

The numbers I put up were for illustrative purposes only. My company is in the online leak repair business and I've been asked to look into options to keep leaks from spraying long distance while the leak is being attended to.

 

[BigInch]

Shut the system down and fix the leak.
You don't play around with 500 psi x 500 F


you must get smarter than the software you're using.

 

[dhengr]

If you’re in the ‘online leak business,’ I’d suggest better passwords, firewalls, security systems, etc. Then don’t go to any more movies which mention North Korea public figures.

 

[LittleInch]

Aren't they called sleeves??

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[chicopee]

I would do some research in the water jet cutting of steel plates.

 

[keyen]

LittleInch, the repair you're referring to (such as shown in ASME PCC-2 Article 3.6 Figure 1) is generally not exposed to blasting because they are (usually) injected with sealant. Even without sealant, there wouldn't be a blasting erosion problem since any void would be filled with the process. My company designs and manufactures these types of repairs. The plate I described in my original post is to contain the process from spraying across long distance while a repair is implemented. There are many cases where shutting down to repair is not feasible (or desired). Our regulatory authority is well aware of the work we perform.

dhengr, somedays I wish passwords could fix the leaks I'm dealing with.

 

[bimr]

I think your failure scenario is very unlikely.

Steel piping does not generally fail in a catastrophic manner. It takes time for a corrosion leak to occur. The leak will start with seepage first, and then take considerable time to enlarge to an 0.125" hole. There will be adequate time to observe a leak before the leak starts damaging other equipment.

If you have a 500 degree, 500 psi system leaking from a 0.125" hole, most people would shut the system down because of the cost of the lost energy.

Water jets use 20,000 psi pressure, so you don't need to worry about cutting through steel. 3/16" plate will suffice for some time.

 

[LittleInch]

keyen,

The difficulty I'm having and maybe a few others are that I can't figure out what you're doing or how you can actually safely work in such a scenario. 500F and 50 psi fluid leaking from a pipe is not to be niffed at.

in terms of sleeves here are some designed to be placed around active leaks to reduce pollution etc, but ether way, your outline of conditions is so low as to not cause any significant decrease in wall thickness.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way