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The plunger engaging safety device (PESD), when used on direct plunger hydraulic elevators to stop uncontrolled descent due to loss of pressure, shall comply with the following requirements:
(1) The forces applied to the plunger shall be compressive and distributed over the circumference of the plunger when the PESD is actuated. The force shall not exceed 28% of the plunger yield stress.
(2) Supports for the PESD shall be capable of withstanding a kinetic force of 115% of the total load stopping with a deceleration of 1 g.
(3) The PESD shall:
(A) actuate when there is a loss of hydraulic pressure that could cause the elevator to go into an out-of-control descent,
(B) not release the plunger if there is downward motion of the plunger,
(C) be fully operational during a primary electrical power failure, and
(D) have sufficient running clearance between the gripping surface and the plunger to not adversely affect the plunger or the gripping surface.
(4) The PESD bearings, when used, shall be corrosion resistant.
(5) Parts of the PESD and supports, except springs, shall have a safety factor of not less than 3.5. The materials used shall have an elongation of not less than 15% in length of 2 inches. Forged, cast or welded parts shall be stress relieved. Roller chains, if provided, shall comply with ASME B29.1M-1993, “Precision Power Transmission Roller Chains, Attachments, and Sprockets,” which is hereby incorporated by reference. Wire rope, if provided, shall comply with Section 3107.
(b) Data Required for Approval.
(1) Two complete sets of detail drawings showing the assembly of the PESD shall be submitted to the Division and shall show the following:
(A) The construction of the PESD and the dimensions of major parts for identification.
(B) The shim adjustment range indicated on the safety marking plate required by Section 3065(b)(3).
(C) Indication of how the clamping surfaces are held in the released position.
(2) The results of performance tests conducted by the manufacturer or approved testing laboratory. These tests shall be conducted to demonstrate that the PESD will function satisfactorily within the range of loads and speeds for which the PESD is to be approved.
(c) Performance Tests Required for PESD Approval.
(1) Tests to indicate that surfaces subjected to friction by the PESD will not reduce the reasonable life expectancy of such surfaces.
(2) Tests to indicate the gripping mechanism of the device does not adversely affect the plunger.
(Title 24, Part 7, Section 7-3106.1)
Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. New section filed 4-13-2000; operative 5-13-2000 (Register 2000, No. 15).