Very High Temperature Analysis

Hi All,

Design and Operating Data's
piping material - Inconel 601 B167 GrB (UN6601)
Ambient Temperature - 6 deg c
Design Temperature - 1100 deg c
Operating Temperature - 950 deg c
Design pressure - 3.4 barg
Operating pressure - 1.5 barg
Hydro Pressure - 3.74 barg

Material database is not available in CAESAR II 5.2 version. Kindly provide me the material data's like allowable stress, yield stress, modulus of elasticity, Poisson's ratio for above mentioned temperatures. Kindly help me, this line is very critical.

With Regards

Elias

You should get the data you need from the material supplier or an ASTM handbook. Also remember that you are in the creep range.

Why is your hydrotest pressure so low (1.1 x design pressure) ? I would expect to find at least 1.5 * des pres. and if B31.3, 1.5 * (ratio of cold / hot allowable stress x des pres.)

You may want to track down ASTM B167 Standard Specification for Nickel-Chromium-Iron Alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696).

Maybe double check your material spec, I could find B167-N06600 in ASME B31.3, but not B167-N06601.

Maybe instead of "UN6601", it may be UNS N06601.

Dear Mr. MonerZ,

Thank you for your reply....

It is not a hydrotest, it is pneumatic test pressure. Process fluid is Gas, so that i taken as 1.1 X design pressure.

In ASTM B31.3 (2008) for B 167 inconel material, for this max temperature is 1200 Deg Fahrenheit (648.88 Deg c), allowable stress is 2 ksi.

But i got data's from our material supplier. Allowable stress at temperature 1100 deg c i.e. 5100 KPa

kindly crosscheck this allowable stress is ok.

Regards

Elias

Your test is a leak test, not a hydrotest. Will the welds in the system ever be tested for safety and integrity?

2 ksi = 13,789 KPa ....
If your supplier says the allowable stress is less than half of that, you need to ask for derivation of his figures. Get Client approval for the accepted data.

Be careful of your units, you are switching between deg F and deg C.

Your Design Temp is 1100 deg C (2012 deg F)

You report B31.3 SA at 649 deg C (1200 deg F) as 13.8 MPa (2 ksi). It appears B31.3 does not give SA values for this material above 1200 deg F.

Material Supplier SA at 1100 deg C (2012 deg F) is 5.1 MPa (0.74 ksi)

The material supplier's SA number does not seem out of line. You need to satisfy yourself that it is appropriate to use this material at this high temperature ( 1100 deg C / 2012 deg F).