What is a flange bolt hole orientation?
A bolt hole is an opening that is employed to install a bolt and affix it in place. Bolt hole orientation is very important to allow the flange or other equipment to be aligned in the right place. Proper orientation allows for proper fixation and stiffness of the material. The Bolt hole orientation standard is the ASME B16.5 or other standards based on the desired applications. The bolt holes are divided evenly on the flange allowing for good locking and sealing in the system. The Pipe flange bolt hole orientation varies based on how the flange is facing, pressure rating, or other characteristics.
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What is the flange bolt holes positioning principle?
The positioning principle of the flange bolt hole determines the no of bolt holes and their diameters in flanges. The Bolt hole orientation diagram specifies the pressure rating and size of the flange for the operation.
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Why Flange Bolt Holes Straddle the Centerlines?
The flange bolts straddle the centerline to create a strong sealing. Here, if a small leakage occurs it will not dip into the hole. The Bolt hole orientation flange will thereby be tolerant to corrosion and failure due to major leaks.
how to Specify Bolt Hole Patterns in pipe flange?
Flange bolt holes are evenly distributed on the bolt hole diameter, and the number of holes is always even like 4, 8, 12, 16, etc
A bolt hole pattern is designed based on the diameter of the bolt holes in the pipe. You can refer Bolt hole orientation diameter chart to get more information. The diameters and numbers per pressure class tend to vary on various features.
What are bolt hole orientation standards?
Bolt hole orientation standards cover material in different standard grades. The common Bolt hole orientation standard is ASME B16.5, ASME B.16.47, ANSI grades, etc.
What is the Hole size of the ANSI flange?
The positioning of bolt holes for flanges is particularly important in the fabrication of prefabricated parts with flanges
The ANSI standard flanges covers American National Standards Institute. These flanges have bolt sizes of 1/8 larger than a bolt or stud. So, Ansi flange bolt hole orientation having a bolt sizes of 5/8 the hole size will be 3/4
Does the flange bolt hole count is same for all flanges?
For an eight-hole flange to be spaced 45° apart, by straddling the centerline, holes will be positioned 221/2° on each side of the centerline
A bolt hole count depends on the pressure rating of a flange. If they have the same pressure rating, then it will be the same. The bolt holes are evenly distributed through the Bolt hole orientation diameter. The number of holes in these flanges are available in even numbers
How to Bolt hole Mark on flanges used in Pipeline?
The bolt hole mark on these flanges can be calculated using a flange hole marking calculator. The flange markings have equ-spaced flange holes, which it employed to calculate the maximum no of holes marked on the flange.
How are flange bolt-holes oriented on flanges on vertical line?
In vertical flange sealing surfaces, the surface of the flange is vertical, with the pipeline running horizontally. Bolt hole orientation dimensions should be used on both the horizontal centerline and the vertical side.