Provincial regulations recently changed with the BCSA issuing Safety Order SO-L1 101214 1 which requires the modification of all existing single bottom cylinder elevators by October 8, 2015.
The Safety Order applies to all hydraulic elevators installed below ground with single bottom cylinders. Most single bottom cylinders have been in the ground for 30 years or more. The potential for catastrophic failure due to the separation of a single bottom from the cylinder increases with cylinder age.
Prior to 1977, the industry standard for cylinders was a single bottom cylinder design. The compounding problem is that most of these cylinders were also installed without a PVC casing which leaves the cylinder unprotected from corrosion. The electrolytic action causes the steel cylinder to corrode and burst. When this happens the column of oil supporting the elevator is expelled into the surrounding earth and the elevator drops in free-fall.
•The original design cannot control the speed of descent if the bottom plate ruptured which would allow all of the oil to escape at once and resulting in a catastrophic failure
•Rapid oil loss causes car to descend out of control
•This may result in injury or death, property damage and environmental contamination
DOUBLE BOTTOM CYLINDER DESIGN
After 1977 the double-bottom cylinder design became the industry standard to protect against failure of the bottom plate.
•This new cylinder design features a bottom plate plus a safety bulkhead equipped with a relief orifice.
•The orifice is designed to limit the speed of the elevator’s descent should a bottom plate rupture occur