Elevator

:This article is about the transport device. For other meanings of the word, see Elevator (disambiguation).

Elevator safety

Elevators are inherently safe. Their safety record, that of moving millions of passengers every day, without incident, is unsurpassed by any other vehicle system. Recently, however, hydraulic elevators built prior to a code change in 1972 have been found to be subject to possible catastrophic failure. The code had previously required only single-bottom hydraulic cylinders; in the event of a breach of the cylinder, an uncontrolled fall of the elevator might result. This concern is reflected in the ASME A17.1 Maintenance of Hydraulic elevators section of the 2000 edition to require verification of system integrity in underground hydraulic elevator cylinders. Because it is impossible to verify the system completely without a pressurized casing (as described below), it is necessary to actually remove the piston to inspect it. The cost of removing the piston is such that it makes no economical sense to re-install the old cylinder, and therefore it is logically necessary to install a new elevator.

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In addition to the safety concerns for older hydraulic elevators, there is risk of leaking hydraulic oil into the aquifer and causing potential environmental contamination. This has led to the introduction of PVC liners (casings) around hydraulic cylinders which can be monitored for integrity. Recent innovations called machineroomless elevators may soon make the use of hydraulic elevators obsolete.

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Elevators are regulated by the Consumer Product Safety Commission and are subject to the provisions of that regulation body. In 2004 the CPSC published a consumer alert about the safe use of escalators.

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