Question: what is the difference between code 61 and 62 flanges?
Answer: The standard series, Code 61, which goes to 3,000 psi and the high pressure series, Code 62, where all the sizes are rated at 6,000 psi. SAE J518 is interchangeable with ISO 6141, DIN 20066 and JIS B 8363, except for the bolt sizes.