I. Tools required for installation
Cleaning and tightening fasteners require a range of specific tools. In addition, only standard installation equipment should be used and good safety practices must be observed at all times.
Prepare the following equipment before beginning installation:
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Calibrated torque wrench, hydraulic torque wrench, or other torque-controlled tightening tools;
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Steel wire brush (brass brush preferred where appropriate);
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Hard hat;
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Safety goggles;
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Lubricant;
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Any other factory-specified tools.
II. Gasket installation steps
1. Inspection and cleaning
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Remove all foreign matter and debris from the gasket seating faces and from all fasteners (bolts, stud bolts), nuts and gaskets.
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Inspect fasteners, nuts and gaskets for burrs, cracks or other defects.
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Check flange faces for distortion or warpage, radial scoring, deep impact marks from tools, or any other defects that could prevent the gasket from seating correctly.
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Defective components must be replaced promptly. If there is any doubt about whether replacement is required, consult the gasket manufacturer.
2. Flange alignment
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Align flange faces and bolt holes.
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Report promptly any condition that prevents proper alignment.
3. Gasket placement
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Verify the gasket is the specified size and material.
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Inspect the gasket to ensure it is free of defects.
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Carefully insert the gasket between the two flanges.
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Confirm the gasket is centered between the flanges.
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Do not apply adhesives or anti-stick compounds unless specifically required by the gasket installation instructions.
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Align the flange faces and ensure the gasket is not nicked or cut during handling.
4. Lubricate load-bearing surfaces
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Only the specified or approved lubricants are permitted on load-bearing areas.
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Apply sufficient lubricant to all threads, nuts and gasket load faces.
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Ensure the lubricant does not contaminate the flange face or the gasket sealing surface.
5. Bolt installation and tightening
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Always use the correct tools.
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Use a calibrated torque wrench or other torque-controlling tightening tool.
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Consult the gasket manufacturer’s technical department for torque requirements and specifications.
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Tighten nuts using the “cross-pattern” (crisscross) sequence.
Five-step nut tightening procedure:
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Initial hand-tightening of all nuts. Larger nuts may be brought up with a small hand wrench.
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Tighten each nut to approximately 30% of the required final torque.
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Tighten each nut to approximately 60% of the required final torque.
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Using the cross-pattern, tighten each nut to 100% of the required final torque.
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Note: For large-diameter flanges, the above steps may be repeated in additional increments.
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Perform at least one final pass by tightening each nut sequentially in a clockwise direction until the required full torque is reached.
6. Re-torquing (after initial operation)
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Note: Consult the gasket manufacturer’s technical department for guidance and recommendations on re-torquing.
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Non-asbestos gaskets and gaskets containing rubber compounds that have been exposed to high temperatures must not be re-torqued (unless otherwise specified).
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Fasteners exposed to corrosion or thermal cycling will require re-torquing.
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Any re-torquing operations should be performed at ambient temperature and atmospheric pressure.

