The Lee Betaplug® Expansion Plug is a pre-assembled, one-piece, tapered expansion plug specifically engineered to seal fluid passages in metal castings and plastic housings leak-tight, without the use of threads or sealants. Controlled expansion during installation causes the lands and grooves on the O.D. of the plug body to bite into the wall of the fluid passage, creating a leak-tight seal and assuring retention. The unique tapered design eliminates the need for tight manufacturing tolerances, and allows the designer to minimize the wall thickness required around the plug, even for brittle housing materials. Note: Betaplugs are not recommended for use above 275°F (135°C).
The 6000 Series Betaplug is designed for high pressure systems (up to 7,000 psi), and is available in 4, 5, 6, 7 and 8 mm diameters. The Short Betaplug is designed for low pressure systems, up to 500 psi, and is available in 7, 9, 11, 13 and 16 mm diameters.
Precise Control of Boss Stress
Conventional, cylindrical shaped expansion plugs require additional expansion for the clearance between the plug O.D. and the installation hole. The matching tapers of the Betaplug and its installation hole create a perfect fit, eliminating the need for additional expansion. Since the Betaplug’s expansion is precisely controlled by the size of the tapered pin, the amount of expansion and any resulting boss stress is completely predictable.