T2a definition in API 650 Variable Design Point 1

[rab1944]

Would someone please define t2a in
API 650 Section 5.6.4.5 (Variable Design Point).

Thanks

 

[IFRs]

t2a = thickness of the second shell course, in mm (in.), as calculated for an upper shell course as described in 5.6.4.6 to 5.6.4.8, exclusive of any corrosion allowance. In calculating second shell course thickness (t2) for design case and hydrostatic test case, applicable values of t2a and t1shall be used.