Do we need to use FJ (Flange with Jack bolt) 2

[tranvietnga1905]

Hi there,
Is there anyone who know that when we need to use FJ?, and why? I am checking isometric drawings, and need to correct where i need to use FJ and where need, because the using of FJ would be more expensive.

Kindest,

 

[nickelkid]

Properly sized Jackbolts can be helpfull during dissassembly of flanges.

What is the process being contained?

 

[tranvietnga1905]

Is it involving to the process contained? could you explain more? I am checking some process gas lines for Gas Seperation Plant.

 

[nickelkid]

The process may be contain components that will cause corrosion or build up of solids in the piping.

If the original iso's probably called out this requirement for a good reason; they had to justify the extra cost too.

 

[vzeos]

tranvietnga1905: Flange jack bolts are usually used on orifice flanges to facilitate the removal of the orifice plate. The settlement of the piping system after fabrication could squeeze the plate so tightly that it would be nearly impossible to remove it. Jack bolts provide a means to spread the flanges. Jack bolts can also be used with other components that are mounted between flanges such as wafer check valves. There should be one jack bolt per flange and when the flanges are installed, the jack bolts should be 180 deg apart. Orifice flanges are purchased with flange taps and jack bolts. See attached pdf.

http://www.emersonprocess.com/rosemount/document/drawings/01497-1003.pdf