Cold Weather

[Althalus]

What exactly constitutes "cold weather" from a steel perspective? There has to be a transition line.
[ol]
[li]I'm looking at a project where lowest ambient temperature is specified as -15C.[/li]
[li]Some projects are only specified as low as -5C.[/li]
[li]Others are as low as -30C.[/li]
[/ol]

Most of the 48 states experience temps as low as 0F = -18C every winter. But most projects don't require A320-L7 bolts. We simply use the standard A325 bolts even for exterior use.

Where is the cutoff for "average low winter temperatures" before you'd start using A320 instead of A325? I have searched everywhere on the net, and I can't find anyone who says "THIS TEMPERATURE" is the cutoff. I'd even settle for a "range" of temperature. But all I ever hear is "cold weather". Without a number, that is pretty much meaningless.

 

[dauwerda]

It's my understanding that A320 bolts are for low temperature service conditions, as in pressure vessels and flanges where the liquids/gasses inside the vessels are very cold (think cryogenic processes, way colder than ambient conditions). It would be very rare for structural steel connections to ever need to use A320 bolts (and if they were needed you probably wouldn't be using your typical structural steel specifications either).

 

[dik]

ASTM A 320 has a grade (Grade L7, and L43) that specifies testing at low temperatures of -150F and are used for cryogenic facilities.

I’m not sure what ASTM F3125, Grade A325 are good for, but I’ve used them for projects at -40C, and I don’t have verification that they are OK for that. They've been used for decades, and I've not heard of anything 'breaking'. For temperatures below that, or maybe even at that you can spec Charpy impact testing at whatever temperature you require. A caution that any treatment may have an impact on test results.

I’ve often spec’d steel to CSA G40.21-350WT and 300WT for cold climates. I was up at Cambridge Bay about 50 years back and experienced -55C, the coldest I’ve ever been.


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

I don't know what A325s are good for, but A320s are for real cold... colder than Antarctica.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

I sent a query on to the CISC to see if they have an answer. I'll let you know the results.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik