Hello Can anyone tell me where ca

[titiz]

Hello
Can anyone tell me where can i find the formula of the maximum velocity of a material (taking under consideration the fluid type).
Can i find it in the ASTM Specifications ?

 

[MikeHalloran]

working from memory, I'm not coming up with a velocity as a material characteristic, but I sure don't know everything.

Could you please add some background and context to your question?



Mike Halloran
Pembroke Pines, FL, USA

 

[LittleInch]

If you mean maximum velocity of a fluid, then no, there are no specifications which list this sort of thing.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EdStainless]

But there are lots of 'rules of thumb' that go into fluid velocity.
Is the fluid clean? is it corrosive? Both of those would reduce the max velocity.
What is the piping material?
Al and Cu (brass as well) have fairly modest upper velocities as they will erode in service. It is expected.
Plain steel is a bit higher, and stainless steel and Ni alloys are really only limited if you have abrasives in the fluid and by your pumping (friction) losses.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[titiz]

Maximum velocity is a characteristic of materials and it changes with the fluid type by a formula, and it must be used for the determination of the pipe diameter. That’s why I’m asking about it, because I can’t use any of the values based on experience.
my fluid type : -steam
-treated water
-boiler feed water
And I have been guided in this way by my Supervisor

 

[weldstan]

Is your supervisor thinking of FAC (Flow Assisted Corrosion)? In which case, appropriate chromium equivalent chemistry of low carbon steel is all that is required in high velocity boiler feed systems in the temperature range of about 200F to 450F. In pipe immediately downstream of the bypass valve, the fluid velocity is near sonic, initially. Your supervisor is wrong in believing that fluid Velocity is characteristic of the material. As previously stated the material's ability to resist corrosion.erosion in high velocity fluids is dependent on its alloy chemistry.

 

[titiz]

I think that may be what he meant.
Thank you for your time, and where may i find more informations on the material's ability to resist corrosion and erosion in high velocity ?

 

[MJCronin]

Aaahhh .... The phrase that strikes terror in the hearts of all engineers on this website ...

" And I have been guided in this way by my Supervisor [/b]"

MJCronin
Sr. Process Engineer

 

[weldstan]

Go to the Web and look up FAC. A number of publications have been made available. Essentially you need a CrE of .17 or greater to meet the corrosion resistance. At least one Japanese mill will be able to provide it in SA-106 C. Because of limited availability, a number of boiler manufacturers and Power Engineers specify SA-335 P11 for these applications. Welding wire (Metal Cored) meeting the CrE can be obtained from DEVASCO in Houston.

MJCronin: So right - the blind leading the blind!