Stud Bolt Selection.
Stud Bolt Selection.
(OP)
Dear All
I have two question regarding material selection for Stud Bolt.
1. Can i select B7 alloy steel stud bolts for SS 316 or SS304 flanges , if it is acceptable how can i justify galvanic corrosion issue due to dissimilar metal contact issue. Any standard reference is highly appreciated. Line class 150, Design Pressure 10 Bar. Design temp 122 F, Service water.
2. Is there any reference or standard to stud selection as per environmental condition, means stud or bolt shall be galvanized or non galvanized or any type of coating is applicable.
3. if all stud are non coated and later on we observed corrosion on studs can we apply the paints or cold galvanizing on all stud without removing from the flange joints.
Please send me any standard reference.
Regards
I have two question regarding material selection for Stud Bolt.
1. Can i select B7 alloy steel stud bolts for SS 316 or SS304 flanges , if it is acceptable how can i justify galvanic corrosion issue due to dissimilar metal contact issue. Any standard reference is highly appreciated. Line class 150, Design Pressure 10 Bar. Design temp 122 F, Service water.
2. Is there any reference or standard to stud selection as per environmental condition, means stud or bolt shall be galvanized or non galvanized or any type of coating is applicable.
3. if all stud are non coated and later on we observed corrosion on studs can we apply the paints or cold galvanizing on all stud without removing from the flange joints.
Please send me any standard reference.
Regards





RE: Stud Bolt Selection.
Galvanising is a sacrificial protection and will not last in a corrosive environment. Some comapies use zinc plated bolts but this lasts but a short time as the amount of zinc is no where near that of HDG.
2. This is more a corrosion philosophy issue and standards are not neant to be design guides. i dont know of such a standard. Generally companies have standards based upon experience in their industry. The durability requirements based on risk, design life etc are used to determine materials of construction.
3. Many stud bolts are protected from corrosion by coatings in grease, mechanical or hot dip galvanising, PEEK, ECTFE or other material. If corrosion is observed it comes down to has it reduced the effectiveness of the stud bolt? Some oil industry companies change their stud bolts routinely. You could installed cathodic protective zinc cups on the ends of the stud bolts and this will provide the same sacrificial protection.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/
RE: Stud Bolt Selection.
RE: Stud Bolt Selection.
rmw
RE: Stud Bolt Selection.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/
RE: Stud Bolt Selection.
RE: Stud Bolt Selection.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/
RE: Stud Bolt Selection.
Many, many vendors...... These have been around forever
Please...... Come back to this forum with your final solution
http://www.ptfecoatings.net/ptfe-coated-studs.html
http://www.stud-bolts.com/products-detail.asp?keyn...
RE: Stud Bolt Selection.
rmw
RE: Stud Bolt Selection.
RE: Stud Bolt Selection.
Now is the point at which the question; "what does the contract call for" is pertinent. If it didn't specify bolting hardware coating, you are stuck and if you want corrosion protection, you will have to pay to have these removed and coated hardware installed. If it calls for coated hardware, then the contractor will have to remove what is there and install what was specified at his expense.
I agree with the recommendation of not using B8 due to the tendency to gall, not that I don't use them on a regular basis with lots of anti-seize and crossed fingers. (As long as there isn't the persistent presence of an electrolye to consider as part of the mix.)
rmw
RE: Stud Bolt Selection.
RE: Stud Bolt Selection.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/