Hi,

I'm using CAESAR II 4.50 and I don't find the same thermal expension for FRP pipe in the "Piping Error Checker" and "Static output Processor" than the one I put in the "Kaux, Special execution parameter".

In the Kaux table (special execution parameter) I put 0°C for the "ambiant temperature" and 30length/length/° for "FRP Coef. of Thermal Expansion x 1 000 000".
In the "Piping input" I put 1°C and I choose the Material "(20)FRP". There is not pressure.
When I run the "Piping Error Checker" Caesar writes that the Thermal expansion is 0.000026 length/length instead of 0.000030! In the "Static Output Processor" it gives for temperature case alone T1 (EXP) a displacement of 0.026mm for a 1 meter pipe run instead of 0.030mm!

I got the same problem using US units: with 1000 inch pipe long, 1°F for T1, no pressure and 0°F as ambiant temperature, the default 12 length/length/° for "FRP Coef. of Thermal Expansion x 1 000 000". With these inputs I got 0.010 in. displacement in T1 (EXP) case instead of 0.012in.

What is wrong?

I'm not exactly sure what you could have done - perhaps your "alpha tolerance" in the configuration has been altered?

I just made a run as follows:
- length = 100in
- ambient = 70 degF
- T1 = 80 degF
- alpha = 12e-6 in/in/deg

The Error Checker report shows the expansion coefficient as 0.00012 in/in, which is correct. The output shows the displacement as 0.012 in, which is correct. The model is attached.

Thank you Richard.

I've found my mistake: I forgot the k factor in UKOOA code which change the thermal expansion!
k = mean temperature change multiplier as defined in section 7.2.1 of the BS 7159 code (0.85 for liquids, 0.8 for gases, 1 for ambient temperature).