Cradle-Lock® Anti-Vibration Tube Stakes
American Efficiency Services proudly announces its acquisition of all legal rights to the Cradle-Lock® Anti-Vibration Tube Stake design. Since November of 1988, Cradle-Lock® has been the industry’s solution for vibration-induced tube failures in steam surface condensers and heat exchangers. Pioneered and patented by Bob Hahn, Cradle-Lock® Anti-Vibration Tube Stakes are now offered exclusively through AES.
Millions of our Cradle-Lock® stakes have been installed since its product launch, in a variety of applications throughout the world. We have a proven record of success in staking condensers and heat exchangers of all make and tube sheet configurations using our designs for straight, back-to-back, beam, and spring stakes. There has not been one reported tube failure as a result of vibration where Cradle-Lock® stakes have been installed.
Tube damage because of vibration occurs when high-velocity steam travels through the tube bundle. Whether by design, a change of tube materials, or the result of a power uprate, the tubes are susceptible to all types of flow-induced vibration mechanisms. Most commonly, failures occur as a result of mid-span collision or circumferential fracture at the tube sheet or support plates. Tube vibration, if left unresolved, may result in catastrophic tube failures and the subsequent unplanned shutdown of the unit.
CONSIDER CRADLE-LOCK® STAKES:
- To eliminate tube damage when increased steam flows are introduced or when retubing with thinner-wall tubes such as Titanium, Sea-Cure®, AL-6XN, or other exotic alloys as a result of vibration.
- To accommodate excessive support plate spacing, especially if the condenser was fabricated prior to 1977, preceding HEI support plate specifications.
- As part of a power uprate project, to protect tube bundles against higher steam velocities.
TECHNICAL ADVANTAGES OF CRADLE-LOCK® STAKES:
- Unlike other clip or “locking” stakes fabricated from a flattened stainless steel tube, all AES Cradle-Lock® stakes are custom-engineered and fabricated of 304 stainless steel using precision dies to precisely mimic the tube pitch and spacing characteristics of your condenser or heat exchanger.
- The indentations (dimples) are what sets our design apart from the rest, providing an interference fit that locks the stakes and tubes into a single vibration-free unit.
- The Cradle-Lock® design “cradles” the tube on both sides of the stake which prevents horizontal vibration and limits vertical movement.
- Our stakes “cradle” the tube throughout the surface area of each indentation, greatly increasing the contact area between the tube and the stake. Conventional stakes offer only one point of contact and allow the tube to move up and down its length
- Cradle-Lock® stakes are easier to install as they virtually eliminate the necessity of wiring, bolting, bands, or other parts.
We Can Help!
Considering a retubing? We can perform a vibration analysis to ascertain if your new tubes will be susceptible to vibration damage.
Experiencing failures and uncertain if these are due to vibration? We can perform an inspection of your tube bundle.
