Brass Vibra-Lok Union

A Brass Vibra-Lok Union is a straight symmetrical fitting engineered to join two tubes of identical outer diameter inline. Unlike conventional compression unions that rely on metal ferrules cutting into the tube surface, the Vibra-Lok Union utilizes two resilient elastomeric sleeves (Buna-N or Viton/FKM). When the brass nuts are tightened, the sleeves compress radially against both tube ends, creating an airtight, leak-proof seal that absorbs dynamic mechanical vibration and mechanical shock.

Long, rigid tubing runs on vibrating machinery act like harmonic resonators, transmitting vibrations directly into rigid tube fittings where metal fatigue causes cracking. The Vibra-Lok Union acts as an inline vibration isolator. By suspending both tube ends in thick elastomeric cushions, it absorbs up to 90% of dynamic vibration, dissipates mechanical shocks, and allows minor axial expansion without stress concentration.

Pioneer Industries supplies Vibra-Lok sleeves in two primary compounds: Standard Buna-N (Nitrile) for petroleum fuels, hydraulic oils, compressed air, and water between -35°C and +100°C (-30°F to +212°F); and High-Temperature Fluorocarbon (Viton / FKM) for synthetic lubricants, aggressive fuels, and elevated operating temperatures from -26°C to +204°C (-15°F to +400°F).

Working pressures reach up to 2,000 PSI (138 bar) in 1/8″ to 1/4″ tube OD sizes, 1,500 PSI (103 bar) in 5/16″ and 3/8″ OD, and up to 1,000 PSI (70 bar) in 1/2″ OD sizes, backed by an ASME B31.3 certified 4:1 hydrostatic burst safety margin. For vacuum applications, its continuous 360-degree radial elastomeric seal holds vacuum down to 29.5 in. Hg.

No. The Vibra-Lok Union is 100% flareless. Installation requires only square-cutting and deburring the tube ends, sliding the nuts and elastomeric sleeves onto the tubes, inserting each tube into the fitting until it bottoms against the central internal tube stop, and tightening the nuts finger-tight plus exactly one full turn (360°) with an open-end wrench.

Because both tube ends are cushioned in compliant elastomer rather than clamped in rigid metal, the union compensates for tube out-of-roundness, surface scratches, and angular misalignments up to 4 degrees. Additionally, the elastomer allows minor axial movement, absorbing thermal expansion and contraction without weeping.

Yes. Because the elastomeric sleeve does not swage, cut, or crimp a permanent groove into the tubing wall, both tube ends remain undamaged and 100% reusable. Disassembly simply requires loosening the nuts. If the elastomer becomes aged or heat-hardened after years of service, inexpensive replacement sleeves restore the joint to factory-fresh sealing integrity.

The fitting is fully compatible with soft copper, half-hard drawn copper, seamless aluminum, brass, thin-wall hydraulic steel, and even lab-grade glass tubing. When utilizing thermoplastic tubing like Nylon or Polyethylene, brass tube support inserts should be inserted into the tube bore to prevent wall collapse.

The Brass Vibra-Lok Union features a precision-machined integral internal center shoulder (tube stop). This positive stop prevents over-insertion of either tube, guaranteeing balanced sleeve compression, symmetric fluid flow passage, and equal mechanical holding power on both sides.

Bodies are machined from ASTM B16 C36000 free-cutting brass or hot-forged from BS 218 / CW617N brass. Every manufacturing batch undergoes 100% pneumatic bubble testing at 10 bar and coordinate measuring inspection of threads, delivered with an authentic EN 10204 Type 3.1 Mill Test Certificate.