B7 compatability

Date 12-14-2012 14:31

I'm not familier with the B7 stud designation, so I can't help too much in reagrds to telling you what it may be similiar too.

I can tell that in the structural world we have three grades of bolts we work with' A307, A325, and A490.
The A 307 are not intended for extreme tightening, they are not made to hold a clamping force.

The A325 and A490 are high strength bolts, that's why we have to test them in a skidmore to make sure the the method the bolting crew uses will meet and or exceed the minimum clamping force required. The grade of nuts we use is A563 and washers is F436 flat washers.
When we test using the pre-installation verification method using the skidmore , an 3/4" diam A325 bolt must meet a minimum of 29 kips ( 1 kip = 1000ft lbs_ so that 29,000 lbs of clamping force.
An A490 3/4" bolt must meet 37 kips or 37,000 lbs of clamping force.

If you go to AISC.org search for Reasearch Counsil on Strucutural Connections (we call it the RCSC in technical lingo) December 31, 2009 edition. It is a free dowload and explains all about our strucutral bolting requirements for structures.

ALso ASTM A325 and A490 you can buy each specification if you want to know capacity and tensile strengths for each grade.

Good Luck
Chris

By Superflux (****)

Date 12-14-2012 18:54

Thanks Chris,

I'll just cross reference the B7 specs with the AISC info you provided.

RFI responses typically are slower than the "second coming of Christ". Seems I'm better off researching and answering my own inquiries back to the EOR than waiting until they shinny down off the ivory pedestal to deal with us commoners.

Thanks,
John

By G.S.Crisi (****)

Date 12-14-2012 18:51

Please clarify. Where are those cap screws going to be installed? On the valve flanges? On the valve bonnet? Somewhere else?
Giovanni S. Crisi
Sao Paulo - Brazil

By Superflux (****)

Date 12-14-2012 20:02

Giovanni,

The cap screws will bolt through a 12" 600# Flange and then enter "Blind Holes" (tapped into the body of a butterfly valve and bottom out at 30 millimeters depth).

I was in your area of planet Earth about 8 weeks ago. Buenos Aires and Mendoza, Argentina.
I had considered going over to Brazil and stopping by to say hello and dinner. However I found out too late, that your country does not issue Visas at the Airport and unfortunately must be arranged in advance.

REGARDS,

JOHN

By eekpod

Date 12-14-2012 20:20

I agree that RFI responces are very slow. Amazing how they can slow down what little progress a job can have.

Good luck.

By G.S.Crisi (****)

Date 12-31-2012 14:34

Superflux,
Sorry for the delay in answering you. I've been too busy in the last days and I havn't open the internet section of my computer during the last two weeks.
I've looked in an old piping spec from M W Kellogg for an ammonia - urea plant, and the specified bolting material for 600# piping for non corrosive service up to a temperature of 398 Celsius is A 193 Gr B7, the same you're having difficulty with. The nut material is A194 Class 2H.
Now, take in account that A193 Gr B7 is a low alloy material suitable for studbolts and also for bolts; so I don't understand why you can not use it for cap bolts. Worst thing that may happen is that you have to buy a B7 round bar and machine it to make the bolts.

Happy New Year, Superflux!
Giovanni S. Crisi

PS nº 1. In fact, American citizens are required to have a visa to enter this country. This is because to enter the USA Brazilian citizens are required to get a visa from the local American consulate.
Brazilian government says that Brazil should give foreign tourists the same treatment their countries give to Brazilian ones.
PS nº 2. What have you been doing in Mendoza? I'm curious to know. Many years ago (more than 40) I took part in the erection of an oil refinery at Lujan de Cuyo, a small city at 40 kilometers from the city of Mendoza.

By Superflux (****)

Date 01-01-2013 01:28

Giovanni,
Thank you for the reply, I have recently located a supplier for B7 stamped cap screws.

On the Mendoza trip...
I finished up a project in Kuwait and needed a vacation. Never having been south of the Equator, I picked Argentina. I had considered making a side trip over to Sao Paulo, but the visa problem made that option impractical. Therefore my journey outside Buenos Aires took me to the wineries in Mendoza. Where we sought out Andean Condors, river rafting, ziplines and overindulgence of Malbec wine. (I assume 2 liters a day might be perceived by some as excessive, but... What are vacations for?)

I'm fairly sure I saw the refinery you speak of on one our side trips. It looked to be a 20,000 barrel (3300 cubic meters?) a day plant about an hour's drive Southwest of Mendoza.
I found the eastern flank of the Andes Mountains to be very similar to my home in Wyoming. Flora, fauna, terrain, elevation and climate made me comfortable.
I'll make it a point to visit Brazil on my next trip to South America, stop in and visit with you.

Happy New Year to you

By G.S.Crisi (****)

Date 01-02-2013 17:00

Yes, it's the same refinery, one hour's drive south west of Mendoza. When we built it it was rated at 10.000 cubic meters per day (about 60,000 barrels). This was more than 40 years ago; I don't know whether it has been revamped since then.
Giovanni S. Crisi