Flange Bolts

[olmedo]

Can somebody please tell me the advantage (or disadvantage) of using STUD BOLTS over Hexagonal Head Bolts for jointing flanges.

Would you know any website that I can read regarding this matter.

 

[STYMIEDPIPER]

This should help but I do not think that it is exactly the information that you are seeking.

Quoting from the NAVCO PIPING DATALOG
"Ordinarily, mild steel bolts are made with upset square heads, although in the larger sizes, such as 1-1/2" and above, it is frequently advantages to use double threaded or all threaded bolts calledstud bolts."
continuing from page 194...
"Bolts of classification ASTM A193 can be secured with forged heads, but for flange bolts it has become almost universal practice to use stud bolts made from bar stock and threaded throughout their length....The continuous threaded structure assures an equal distribution of elongation when the bolts are tightened and avoids concentration of stresses which exists in partially threaded stock due to varying cross sections."

 

[pennpiper]

Try here;

http://www.bgmfg.com/stud_bolts.htm

 

[BigInch]

Studs minimize torsional loading to the bolt.

http://virtualpipeline.spaces.msn.com

 

[unclesyd]

In these days and times, costs.
A stud bolt and 2 nuts for the majority of the A193 alloys will generally be considerably cheaper than a hex head bolt and nut. This cost of a stud and nust can be from 25% to 50% of the cost of a hex head.

Another factor is that there is can be a lead time for hex head fasteners as studs can cut to order quickly.

 

[rconner]

In at least USA water and wastewater plant construction, it is common practice to install many wall and floor pipes (with thrust collars etc.) often ahead of assembly of the rest of the piping inside the structures. The use of a flange "tap for studs" (instead of a conventional drilled hole) allows a contractor e.g. to initially place a wall pipe reasonably flush with his standard, reusable wall formwork (with this scheme the contractor does not necessarily need to make a cut-out for the piping/cut a hole out of/render the wall form less useful for other future wall work) if he employs a special tapped, instead of drilled, flange and studs, instead of bolts, for the first interior joint assembly. In other words, at any time after removal of standard reusable formwork, the contractor can screw studs into the tapped holes (of course providing same are kept clean of concrete) and thereafter hang the gasket and the first interior etc. piping. It is arguably at least more cumbersome to in some fashion utilize drilled flanges and conventional bolts for such embedded wall penetrations.