Dear Expert,

I found this criteria in one of the FRP Handbook by the Vendor.

STRESS ANALYSIS NOT REQUIRED
• Pipes ≤ 2 “
• Non restrained joints (Double Bell Coupler)
• Design pressure below 1 barg (drains)
• System with anchor / thrustblocks


Need your opinion as why stress analysis is not required for the non restrained joints (double bell coupler)?

I have this issue that the Contractor has installed a non-restrained GRP pipe and the Client wants to check this with the stress analysis.

Thank you very much and your quick reply will be highly appreciated.