Selection of bolt materials for low-temperature high-pressure towers
Thread Content
The existing column is used at a temperature of -62.7°C; its design temperature is -196°C, with a design pressure of 6.5 Mpa and a test pressure of 8.37 Mpa. The 32 (M70) bolts at the flanges of this column are made of 304 material. During the hydrostatic test, when the pressure reached 6.8 Mpa, abnormal noises were heard from those bolts – this is likely due to the low strength of the stainless steel bolts, which were stretched under high pressure and thus produced noise. There are two possible solutions: using 30CrMoA studs and 30CrMoA nuts, or A193B8-2 studs and A194B8 nuts. The first option can only be used at temperatures down to -100°C, while the second option’s maximum bolt size specified in the standards is M36, and its strength is not much higher than that of 304 material. Which expert can help? Is there no suitable bolt material for this operating condition at the moment?
This post was last edited by SDHZZXM on 2017-6-9 at 11:57. Operating temperature: -62.7°C, design temperature: -196°C. Why is there such a big difference? Where can I find A193B8-2?
A193B8-2 stud + A194B8 nut. It’s produced by that factory.