SEALING
mono-axial and multi-directional tapes . For instance , mono-axial tape can be easily crossed or overlapped at the ends , making installation simple . In contrast , the compression behavior of multi-directional material means that installers must ensure the tape ’ s ends are correctly skived at specific angles and overlapped to avoid gaps in the seal . While this makes installation slightly more complex , it offers high durability and is especially important in sensitive applications . It is always best to follow recommended procedural guidelines when installing ePTFE tapes . The following are examples of installation guidelines for both styles of ePTFE tape .
A closer look at installation processes
Installation Instructions for Mono-axial gasket-tape , such as Teadit style 24B :
• The sealing area must be clean and free of grease . Damaged parts must be repaired or replaced . All bolts and nuts should be well greased .
• Gradually remove the backing paper from the adhesive strip and affix sealant tape inside the bolt circle , beginning at a bolt hole .
Image 2 : Depiction of multidirectional tape installation .
• Complete the gasket by overlapping both ends in front of a bolt either crossed ( approximately 20 mm , 1 inch – Image 1 , Fig . 1 ) or straight with a cut in skived manner ( Image 1 , Fig . 1.1 ).
• Torque bolts in the correct sequence to the desired load . Recommended load : 25 to 30 N / mm 2 .
• If the sealing surfaces are damaged and uneven , use the next bigger joint sealant tape size .
• For particularly difficult sealing problems ( flange rotation , vibrations or similar ) two strips of tape can be used ( Image 1 , Fig . 2 ).
• To avoid distortion of thin flanges and / or to avoid damage to stress-sensitive connections , apply Teadit 24B in an irregular pattern as shown in Image 1 , Fig . 3 .
Image 1 : Depiction of mono-axial tape installation .
Installation Instructions for multi-directional tape , such as Teadit 25BI :
• The sealing area must be clean and free from grease . Damaged parts must be repaired or replaced . All bolts and nuts should be well greased .
• Cut the beginning of the tape with a sharp knife in a skived manner ( Image 2 , Fig . 1 ).
• Remove the backing paper from the adhesive strip and stick the tape onto the sealing area , beginning at a bolt hole .
44 Valve World February 2025 www . valve-world . net