API 650 Design Metal Temperature

[Soln]

When a customer doesn't provide a minimum design metal temperature I'm left with Figure 4.2 (in API 650), Isothermal Lines of the Lowest One-Day Mean Temperature. AWWA D100 states that the design metal temperature shall be taken as the lowest one-day mean ambient temperature +15°F. Can I get away with this in API 650 as well?

 

[Soln]

Yes, see API 650 3.6.