Use a Limit Nut on Gates

Message: Use a limit nut on gates to prevent over extension or over tightening.

---

Over tightening of the gate in this Montana Dam caused the stem to bend, making the gate inoperable. The result was a total loss of reservoir contents.

• 

  This gate wouldn’t close following routine operation.

• 

  The Reservoir began to drain

• 

  Once the reservoir was empty, it became obvious the gate stem had bent.

• 

  This gate wouldn’t close following routine operation.The Reservoir began to drainOnce the reservoir was empty, it became obvious the gate stem had bent.The dam operator had opened the gate too far, pulling the gate leaf out of the guides. When he tried to shut the gate, the gate would not go back into the guides. Continued reefing caused the stem to bend and the gate to break. Result total loss of reservoir contents.

• 

  Use a limit nut on gates to prevent over extension or over tightening and don’t reef on non-operating gates.

• 

  Example of a limit nut.

Note: The content on this page was originally created as part of DamOutletWorks.org (DOWL, 2018). It has subsequently been updated and reformatted as part of the Dam Safety Toolbox.
Revision ID: 3151
Revision Date: 09/15/2022