Hot Dip or Cold Galvanized for Stud bolt in Piping

[jafary64]

Hi my friends,

I would like to know if there is a standard or mandatory requirement for using hot-dip galvanization for stud bolts in piping. When can cold galvanization be used instead? Is this coating allowable in process piping within refineries and petrochemical facilities?

I prefer to use hot-dip galvanization for my project, but our documentation does not specify whether to use hot-dip or cold galvanization. I am searching for relevant references.

Thanks a lot!

 

[LittleInch]

AFAIK, corrosion protection for bolts and nuts is a choice, not a requirement of a code. You will often see it in company specifications and requirements but not in a design code.

Galvanising stud bolts is a bit hit and miss as the coating often becomes damaged and is then "touched up" with cold Galvanising material

 

[The Obturator]

Hot Dip Galvanising was (almost) a standard requirement for valves used in the north sea offshore oil and gas industry. There are various standards how to apply it. The major one being ISO 10684.

 

[SJones]

Spin dip ASTM F2329 tends to give better results. As you mention “Petrochemical” watch out for flange temperatures.

 

[dvd]

Cautions on hot-dip galvanizing high-strength structural bolts and temperature limits on galvanized bolts - you can extrapolate to your situation.

 

[TugboatEng]

Zinc-aluminum flake coatings outperform hot dip galvanizing and can be used on all strength classifications.

 

[jafary64]

Zinc-aluminum flake coatings outperform hot dip galvanizing and can be used on all strength classification

Thank you for your response. I am looking for the applicable standard or regulation that mandates the use of hot-dip galvanized coating versus cold coating in gas and oil field applications Do you know any standards related to this?

 

[HTURKAK]

Having worked in oil and gas industry in past, AFAIK , galvanized bolt is not a mandatory requirement but if the chosen coating is zinc coating , it shall be hot dip galvanized.
I looked PIP PNSM0120.

the relevant statement ' .. galvanized bolting shall be hot dipped in accordance with ASTM A153.

 

[LittleInch]

Thank you for your response. I am looking for the applicable standard or regulation that mandates the use of hot-dip galvanized coating versus cold coating in gas and oil field applications Do you know any standards related to this?

You'll be looking for a long time because it doesn't exist.

COMPANY standards may exist which require this, (Shell, ExxonMobil, BP, Total etc), but no such standards or regulation exists.

Why do you think such a thing exists or is this something you've been told without that person giving you the reference?