i need to know the torque value?? 2

[akr1982]

i have a problem with bolt tightening torque value for 16" & 24" 150lbs with neoprene gasket.
can anyone help me, to find out the torque for the bolts?

 

[SNORGY]

Your best bet is to get bolt torque tables from the gasket manufacturer.

Regards,

SNORGY.

 

[jeffkorte]

Bolts are a wedge with force multiplier. The force gets multiplied by 12 inches divided by the radius of the bolt. A half inch bolt is 12/.25. which is 48. The coeffiecient of friction is .2 . Steel on steel. A wedge only has a force multiplication of about 2. A force diagram for a wedge can be drawn showing the normal force. The angle of the wedge is the angle of the thread. Sin of the angle is (1/13)/( pi x Diameter). I wrote a short program on a commodore computer about a year ago and put it on a 5 1/2 inch disk. Foot pounds. The wedge is about 2 or 3 at the most. The bolt also has a torque from the bolt head.

 

[byrdj]

Does the flange design have a gasket compression limiter?
If so, I would use at least 30% of the bolt yield. I would expect the 16" to use 1", thus about 250 to 350 ft-lbs and the 20" to use 1 1/8", thus about 350 to 475 ft-lbs (with the threads and faces well lubricated with anti-seeze compound)

if no limiter,then gasket compression force is need. If gasket compression pressure is provided, then the gasket dimensisons are needed. assuming 1/2" wide gasket, the above would be about 15Kpsi.

 

[dinjin]

Nothing is that simple as to calculations. You need to know the surface area under the gasket, the thickness of the gasket, the number of bolts, and on and on. I like Snorgy's answer.

 

[Cockroach]

Look into API 6D, and related specifications. These would be dictated also by various ANSI codes for flanges.

 

[lganga]

Take a look to the book " Pressure Vessel handbook" (Moss), there is a chapter for the torque calculation in the forces exerted due to pressure on the flange.
Regards

 

[RAF58]

Hi, actually, for the design of a bolted joint is necessary to have more information than you said. What is the material of the flange and screw step? How much pressure can the gasket support?
Thus, torque means nothing if you need to clamp load.
Sorry, but to have a better answer more detail is needed.

 

[btrueblood]

Hunh. I thought the general procedure was to tighten the flange until the leak stopped?

 

[DLite30]

Hunh. I thought the general procedure was to tighten the flange until the leak stopped?

in an alternating star pattern....lol