CCMech,

If ISO 14692 is the FRP piping design/analysis code, then the Vendor should provide ALL the input parameters' values in order to define completely the FRP material failure envelope.

ISO 14692 Part 2 (16492-2) provides a complex set of FRP material testing & qualification procedures. Based upon these procedures, ISO 14692 Part 3 (ISO 14692-3) details the FRP piping design procedures, including the FRP material failure envelope definition.

If you have not worked with ISO 14692 Standards before, please see for details ISO 14692-2, Section 6 (Qualification Programme)and ISO 14692-3 entirely. An important detail, for a beginner, ISO 14692 Part 1 (ISO 14692-1) contains all the terminology definitions employed by ISO 14692 standards.

So, if FRP piping for your Project is to be designed, manufactured and tested in accordance with ISO 14692, then you have to get (from Vendor, of course) ALL the input parameters that define FRP material failure envelope (see ISO 14692-3, Section 7.11).

Regarding the hydrostatic design stress, it depends what hydrostatic test data you've got from the Vendor: have you got the Short-Term Hydrostatic Pressure STHP (and the corresponding short-term hydrostatic hoop strength STHS), determined in accordance with ASTM D 1599, OR the Long-Term Hydrostatic Pressure LTHP (and the corresponding long-term hydrostatic hoop strength LTHS), determined in accordance with ASTM D 2992 ?

For ISO 14692, the basic strength parameters are the Qualified Pressure "pq" and the corresponding Qualified Stress "sigma qs", which are established in relation with above LTHP (ASTM D 2992, procedure B) - see ISO 14692-2, Section 6.2.3.1. "pq" corresponds to 20 years lifetime, working temperature not higher than 65 C Deg, neutral working fluid and unrestrained-ends plain pipe loading (i.e. 2:1 pressure loading in hoop and axial directions).

Depending on the actual piping loading regime (temperature, lifetime, loading-unloading cycles, corrosive working fluid), ISO 14692 provides appropriate de-rating and correction factors.
Definitely, VENDOR should be consulted regarding these evaluations.

If the short-term hydrostatic test strengths are employed (i.e. the above STHP and STHS, as per ASTM D 1599), then a scale factor "fscale" should be used to perform the transition from the short-term strength parameters (i.e. short-term failure envelope) towards the long-term strength parameters (i.e. long-term failure envelope) - see ISO 14692-3, Section 7.11. In this case, VENDOR should provide "fscale" parameter.


So, to conclude, FRP piping analysis may be performed exclusively in accordance with ISO 14692, ONLY IF FRP Piping Material is designed, manufactured, tested and qualified in accordance with ISO 14692 provisions.

If the above condition is not satisfied, then you should establish TOGETHER with FRP piping VENDOR the specific analysis approach. However, as I previously noted, Vendor must take the responsibility for the allowable stress values if the flexibility analysis does not follow coherently a recognized international code provisions.


Best Regards,