1.
In
570 course, when we calculate the minimum required thickness for rerating
calculation, we noted that the calculated thickness is evaluated from the
famous equation t = P*d/2SE, here the original thickness added based on
calculation concerning mechanical loading (valves, fitting …), thermal
expansion and other sources of external pressures; all these factors are
negligible in the rerating equation, how???.
2.
In ASME B31.3, PWHT is a requirement for P-1 steels
for thickness t > 3/4" (19 mm), where in ASME VIII PWHT is a
requirement for t ≥ 1 1/4" (32 mm), could you discuss why there is a
difference?.
3.
In ASME B31.3 piping construction code, how can we
differentiate between the normal and severe cyclic condition in terms of
practical issues of pressure, temperature and operation condition, rather than
the theoretical issue of fatigue stress analysis mentioned in the code
regarding the severe cyclic condition terms? On the other hand have the oil
flow lines installed to the chrism's tree of oil producing well to be
considered exposed to severe cyclic condition?
4.
Under severe cyclic conditions, the
expanded joints should not be used. What is the alternative to maintain the
thermal expansion mechanism, and other functions induced by expansion joints?
5.
How can the cold spring technique
introduce the intentional deformation of piping during assembly to produce a
desired initial displacement and stress?
6.
Tapped holes for pressure retaining bolting in
metallic piping components shall be of sufficient depth that the thread
engagement will be at least 7/8" times the nominal thread diameter, while
in another code paragraph the engagement will be accepted if it is more than
one thread in the nut. Is there is a difference?
ASME B 31.3 & API 570
