I am analyzing a 30" diameter FRP system at 100°F and 140 psig. I am getting really high loads from thrust due to pressure. From hand calcs using the formulas in the mfr's catalog, the loads should be opposite what CAESAR is telling me. In other words, the pipe should effectively contract (pressure expanding the pipe radially would contract the pipe axially). COADE's stance is that the program implements Eq. 7.3 of BS 7159, but disagree as to whether the equation itself is correct (Did I state this correctly, Richard). It turns out that elongation due to pressure (Bourdon effect) is always larger than contraction due to pressure (radial expansion), according to Eq. 7.3 of BS 7159.

Basically, I'm getting conflicting results from CAESAR and mfr data.

Do any of the wizards out there have similar experiences they'd like to share?

TIA,