I am doing a Stress Analysis for RTRP Epoxy Resin pipe (Underground Piping) nearly 27 km as per ASME B31.4 code, since there is no standard material database in Caesar II, i approached the vendor to provide the details, in which Specified Minimum Yield Strength (SMYS) value is not provided. Can someone tell me the value of it, or formula to calculate the SMYS value. The design data is as follows,

1.Max. Design Temperature - 93 Deg C.
2.Min. Design Temperature - 21 Deg C.
3.Design Pressure - 1778 KPa.
4.Factor of Safety - 1.8

Paldex,

I have not used B31.4 as design code basis for RTRP/FRP Pipes. Most widely used code is ISO14692 and/or UKOOA. If your clients insist on using ASME codes, you can refer to ASME CASE N-155-2, this is the closest you can get which is basically referenced from Nuclear standards. As per my own experience, non-metal pipe displays no yield point, mostly we use the same allowables for occasional conditions. As per stress allowables, you need to ask your vendor to provide Hydrostatic Design Test ASTM D2992 Procedure A, and Procedure B (LTHS, LCL). And after that, you need to do some reading and research.

Cheers & Goodluck!

As said above, RTRP has no yield point. Apart from ISO14692 and UKOOA you can also use BS7159 for FRP piping.
The safety factor you use (1.8) seems low to me. For long term use a safety factor around 4 looks more appropriate. For occasional conditions that only occur in the first part of the life of the piping you can use a lower safety factor.
Be careful with the data from the manufacturer. Check how he determined the material properties and in which direction these are given.
For underground RTRP piping checking for local failure due to high loads (road/rail crossings for example) is necessary.

You also need to check buckling requirements (Euler's) and shell buckling criteria.