Last Updated on October 1, 2023 by Ossian Muscad
In various industrial initiatives, tightening flange bolts is one of the major routine tasks. So, it is crucial to understand the proper, scientific way to tighten flange bolts. Read on and learn the essentials in the tightening procedure and torquing of flange and bolts below.
What is a Flange?
A flange is a flat, ring-shaped, or circular disc with holes placed equally along its edge. It is used in various industrial applications to connect or join two pipe lengths, equipment, or other components. It is often composed of metal, plastic, or another material. Flanges are key in constructing safe and leak-proof connections for pipelines and other systems that transfer fluids or gasses.
A torque wrench is used to tighten flange joints to the proper Torque. The clamp load exceeds a fastener’s proof load by more than 75% created when tightening. To take advantage of pre-loading, the screw’s clamping force must be greater than the joint separation load.
Importance of Properly Torquing the Flange
Properly torquing a flange is crucial in numerous industrial applications, particularly in piping systems that transfer fluids or gasses. The torquing procedure, which entails tightening the bolts or other fasteners holding the flange to the component it is aligning with, is essential for a number of reasons:
- Leak Prevention: Torquing a flange is primarily done to ensure a tight seal between the flange faces. This seal is crucial for stopping system leaks. The risk of leaks is decreased by proper Torque, which guarantees that the gasket, which is normally positioned between the flange faces, is compressed evenly and effectively.
- Safety: Pipeline leaks can be a severe safety risk, especially when working with combustible or hazardous substances. Torquing flanges correctly reduces the possibility of leakage, which could result in terrible disasters and environmental harm.
- Environmental Protection: Leaks can cause environmental harm and pollution. Ensuring flanges are properly torqued decreases the possibility of spills or emissions, which helps protect the environment.
Tools to Use in Torquing Flanges
The right tools for the job and experience are required for successful flange and bolt tightening:
- Impact Wrenches
- Hand Wrenches
- Beam and Gear Assisted Hand Wrenches
- Hydraulic Bolt Tensioners
- Hydraulic Torque Wrenches
Pre-checks for Flange and Bolt Tightening
Pre-checks must be carried out before tightening bolts to guarantee the right fit, current condition, and reliability of flange connections. Here are some pre-checks you should consider:
Flange Condition
- Examine the flange faces for dimensions, damages, dirt, and scratches.
- Look for tool marks and corrosion cracking.
- Examine the seating areas for the gaskets.
- Check for flatness, absence of pitting, and severe wear in the areas of the flange in which the nuts should fit.
- It is essential to keep RTJ Grooves clean, corrosion-free, and intact.
Flange Alignment
Check the flange alignment visually to make sure the fit is correct. Ensure no remaining tensions are in the joint before matching the flanges. Thermal correction for flange alignment is a bad practice that ought to be stopped completely.
- Flange faces must be aligned and parallel.
- The flange bolt holes must be lined up for the bolts to slide through easily.
Nuts, Stud, or Bolts
- Before installation, visually inspect nuts, studs/bolts to ensure they are clear of faults such as corrosion and broken threads. It is not advisable to utilize nut-bolts with broken threads.
- To prevent excessive threading and short bolting, measure the length of the stud or bolt. Flange bolts must be provided with insufficient length to accommodate bolt tensioning tools, separators, drip rings, wafer valves, or additional gaskets.
- After cleaning, check to see if the studs and nuts are clear of burrs visually. A wire brush must be used to clear any debris from the threads of studs and nuts. Threads and nuts that come into touch with flanges can be lubricated. The gasket seating area and surrounding area must not be lubricated.
- Before use, the material grades of the bolt and nut should be appropriately identified. When attaching the nut to the bolt, the identification label on the nut must always face outward.
- It is only allowed to reuse bolts and nuts if it is clear that their components have not been overused or past their yield point.
Gasket
- Avoid using paste, adhesive, or sealing compounds on flange faces or gaskets.
- Gaskets should be visually inspected to ensure they are defect-free before reinstallation.
- Color coding must be maintained according to the type and rate of gasket supplied by the manufacturer.
- Wire brush the seating face of the gasket.
- Check if the material matches the specifications, then check the gasket for any potential flaws or damage like folds or creases.
- Whenever a joint needs to be closed after being opened, all soft material gaskets must be changed with a new set.
- A spiral wound gasket is good for one use only.
Flange Bolt Torque Sequence
When all pre-checks are finished, you can now tighten the stud using the specified torque sequence that was previously mentioned. Use an average of three torquing cycles and the maximum bolt tension to tighten bolts and nuts in a “CRISS-CROSS” pattern.
- Cycle 1: According to the torque sequence, the Torque is up to no more than 30% of the final torque amount. Check if the gasket is being compressed evenly.
- Cycle 2: Maximum Torque should be set at 60% of the final Torque.
- Cycle 3: Tighten to the maximum possible Torque (100%).
When the nuts have been torqued three times using the basic torque passes, torque them at least once more using the final Torque in a “CRISS-CROSS” motion until no more nut rotation is perceived.
Ensure the Proper Torque Measures with DATAMYTE
When safety and quality counts, you look to the industry’s leading precision wrench specialist, who harmonizes the latest innovations with your quality objectives to boost your bottom line’s profitability. DATAMYTE is a recognized industry leader providing a range of torque products designed to enhance accuracy and efficiency in various manufacturing environments.
It also offers real-time reporting and torque data collection to improve and monitor Torque continuously. It’s a comprehensive system for managing all aspects of torque control, from data collection analysis and reporting.
New Generation of Digital Torque Wrenches
DATAMYTE has introduced a new generation of their LightStar™ Carbon Fiber Torque Wrench. These digital torque wrenches offer optimum performance and accuracy, making them ideal for demanding industrial applications.
The LightStar Torque Wrench
Powered with SMARTWRENCH™ TECHNOLOGY for precise auditing, this torque-measuring tool is designed to eliminate false readings that are difficult to detect and is built to be lightweight and strong to handle all sorts of manufacturing conditions. The LightStar Torque Wrench series technology sensor also ensures the operator can pull at any point on the wrench and receive an accurate measurement.
DATAMYTE also provides digital solutions to make your pre-check auditing and inspections fast and accurate! The DataMyte Digital Clipboard is a low-code automation software with an intelligent form and checklist builder that uses a pre-built template.
These drag-and-drop particular items need to be inspected and employ completed checklists immediately with one tap deployment. Our efficient built-in data gathering and analysis capabilities enable quick and precise assessment of attaining proper torque range.
With DATAMYTE, you have all the solutions for accurate torquing and flange-tightening procedures. Why not visit us today? Schedule a FREE DEMO to learn more about DATAMYTE!
Conclusion
The secret to ensuring secure pipeline connections is tightening the flange bolts to the proper torque range. Flange bolts can increase work efficiency and save financial losses by being properly torqued and tightened.
