ASME B16.5 Flange Bolt Chart
A Flange Bolt Chart is a table used to display the size, quantity, and related information of flange bolts. This table helps users quickly find the required bolt specifications to ensure the correct and safe flange connection. The chart generally contains regulations and requirements for flange size, bolt quantity, bolt size, bolt hole size, and torque value.
Below is a commonly used Flange Bolt Chart in the ANSI/ASME B16.5 standard. You can download the Flange Bolt Chart PDF here.
What is Flange Bolt?
A flange bolt is a specialized fastener designed to connect flanges. It plays a critical role in piping systems by providing the necessary strength and sealing capabilities to ensure secure flange connections. Flange bolts are essential for ensuring a leak-free and secure connection between flanges.
Types of Flange Bolts
- Machine Bolts with Nuts: A machine bolt is a bolt with a full or partial thread and usually has a hexagonal head or other type of head. It is secured by threading it into a matching nut.
- Stud Bolts with Nuts: A stud bolt is a rod with threads on both ends, usually without a head. The threaded portions at both ends are screwed into a nut, or one end is screwed into a pre-drilled screw hole, and the other end is screwed into a nut.
According to ASME B16.5, bolts with nuts on both ends are recommended for all exceptionally high-temperature applications for flange joints.
What is the Flange Bolt Torque Sequence?
Flange Bolt Torque Sequence refers to the order in which the flange bolts are tightened to ensure that the flange is evenly stressed and avoids deformation or leakage. The correct tightening sequence is essential to maintain the integrity and safety of the connection.
Why is the Flange Bolt Torque Sequence needed?
If the correct torque sequence is not followed when tightening flange bolts, uneven stress on the flange may cause deformation or failure to form an effective seal. The proper torque sequence helps to evenly distribute the tightening force, ensure a flat and tight fit of the flange, and reduce the risk of leakage.
Common Flange Bolt Torque Sequence
Typically, the tightening sequence of flange bolts adopts a cross-symmetrical manner to ensure that each bolt is evenly torqued. The following is the standard tightening sequence:
1. First tightening: Tighten all bolts sequentially to 30% of the recommended torque.
2. Second tightening: Tighten all bolts further in the same sequence to 60% of the recommended torque.
3. Final tightening: Tighten all bolts in the same sequence to 100% of the recommended torque.
Recheck: Check and confirm that all bolts have reached the final torque in a clockwise direction.
Summary
Flange bolts are crucial components in piping systems. They provide the necessary strength and sealing capabilities to ensure the stability of flange connections. Understanding the various types and specifications of flange bolts enables engineers and technicians to uphold the integrity and safety of system connections.
Related resource references:
https://www.extreme-bolt.com/flange-bolting-chart-asme-b16-5.html
https://eriks.co.uk/en/know-how-hub/blogs/sealing-polymer/talking-torqueing/
