Will bolts used to connect flanges made of different materials cause any reaction?
Thread Content
This post was last edited by tyghbngh on 2015-9-20 at 11:21. One end of the flange is made of 16Mn, while the flange cover is made of grade 20 steel. The pressure ratings are class600 and class900. The bolts used are 35CrMoA. The sealing surface of the flange is of the RF type, and metal-graphite wound gaskets are used. Natural gas is transported through this system. Will corrosion occur between these two types of flanges once they are bolted together?
That won’t happen; if it’s a stainless steel flange, electrochemical corrosion will occur between stainless steel and carbon steel.
For different pressure levels, the number and size of bolt holes vary
I was asking whether corrosion would occur; you mentioned the manufacturing specifications, and those can be found easily
The kind you mentioned won’t work; it cannot be used on pipelines with strict requirements.
Theoretically, it is possible, but can steel grade 20 withstand low temperatures?
What reaction? Isn’t this something quite common?
Could you tell me the relevant writing guidelines regarding the fact that strict pipelines cannot be used in this way?
Over there, the lowest temperature is around minus 10 to 15 degrees – is that considered low?
No, materials that can be welded together are still viable; then bolted connection is even less of an issue.
For temperatures above -19 degrees, 20# steel is perfectly fine.