Section 408.17716. Bucket elevators generally.

(1) Bucket elevators shall not be jogged to free a choked leg.

(2)    All belts and lagging purchased after June 8, 1988 shall be conductive. Belts shall have a surface electrical resistance of not more than 300 megohms.

(3)   A bucket elevator shall be equipped with a means of access to the head pulley section to allow inspection of the head pulley, lagging belt, and discharge throat of the elevator head. The boot section shall also be provided with a means of access for cleanout of the boot and for inspection of the boot, pulley, and belt.

(4)   An employer shall do either of the following:

(a)   Mount bearings externally to the leg casing.

(b)     Provide vibration monitoring, temperature monitoring, or other means to monitor the condition of those bearings mounted inside or partially inside the leg casing.

(5)   An employer shall equip a bucket elevator with a motion detection device that will shut down the bucket elevator when the belt speed is reduced by not more than 20% of the normal operating speed.

(6)   An employer shall do either of the following:

(a)   Equip a bucket elevator with a belt alignment monitoring device that will initiate an alarm to employees when the belt is not tracking properly.

(b)    Provide a means to keep the belt tracking properly, such as a system that provides constant alignment adjustment of belts.

(7)    Subrules (5) and (6) of this rule do not apply to grain elevators that have a permanent storage capacity of less than 1,000,000 bushels if daily visual inspection is made of bucket movement and tracking of the belt.

(8)   Subrules (4), (5), and (6) of this rule do not apply to either of the following:

(a)     A bucket elevator that is equipped with an operational fire and explosion suppression system capable of protecting at least the head and boot section of the bucket elevator.

(b)   A bucket elevator that is equipped with pneumatic or other dust control systems or methods that keep the dust concentration inside the bucket elevator at least 25% below the lower explosive limit at all times during operations.

History: 1988 AACS; 1997 AACS; 2014 AACS.