Look at Chaper III, Section 323.2. It lists all of the toughness test requirements for low temperature service.
Basically if you are designing a system for temperature below the minium temperature allowed by Table A1 or Fig. 323.2.2A you must do impact tests. Doesn't matter if it's A106 Gr B or A335.
Be careful with the A335. It is P5 material and can have anywhere from .5% Cr all the way up to 9% Cr. Depending on the Grade and/or P No. These not only require impact tests for low temperature service but also require preheat, PWHT and radiography must be performed after final PWHT (B31.3, 341.3.1 (b)).
Preferrably after about 48 hours.