AIGI Environmental Inc.
AIGI OvOn™ Bidirectional Live-Loading Disc Springs
AIGI OvOn™ is an internationally patented, bidirectional live-loading disc spring system for pipeline flanges. Where conventional live-loading only compensates one way, OvOn™ responds both when pressure or temperature rises and when it falls, helping prevent bolt yielding, gasket crushing, bolt relaxation and the flange leaks that follow.
Product Benefits
- Works both ways: It can flex downward to absorb a sudden pressure surge or temperature rise, and spring back upward to make up for bolt relaxation.
- Two-stage control: A two-stage load-deflection curve first brings the bolt to its required standard load, then the second stage edges toward the bolt yield load in a controlled way.
- Uses existing hardware: Unlike stretching nuts or stretching bolts, OvOn™ works with the joint's existing nuts and bolts and is reusable, keeping both initial and operating costs low.
- Protects bolts and gaskets: Controlled loading reduces the risk of yielded bolts, crushed gaskets and leakage through start-ups and shutdowns.
Where It's Used
- Pipeline flanges: Flanged joints that go through pressure and temperature swings as lines start up and shut down.
- Critical process pipework: Flanged pipework where a leak would be costly or unsafe.
- With Fishbone® gaskets: Paired with the AIGI Fishbone® gasket, OvOn™ gives the joint a double insurance as part of the AIGI STILL® system approach.
Good to Know
- Two versions: OvOn™ 17-7 PH suits ordinary stainless steel or grade 4.6 bolts and lower temperatures, while OvOn™ H-13 suits high-strength grade 8.8, A193-B7 or SAE 8 bolts and higher temperatures.
- Chemical environments: Both versions can be nickel plated to resist chloride-ion corrosion.
- The STILL® approach: STILL stands for Seal, Lubrication, Installation, Live-loading and Torque, and installation follows the AIGI STILL® video guide.
- Not a tensile spring: Live-loading disc springs are thick, high-load and low-stroke, sized to bolt and gasket loads, unlike the thin tensile disc springs used for mechanical stretching.
