Section 26.14 - Roped Hydraulic Elevators(1) Piston rods of roped hydraulic elevators shall be so constructed and so roped that the piston shall be stopped before the car can be drawn into the overhead structure. Travel limiting stops of ample strength shall be provided in the cylinder to bring the piston to rest under full pressure without damage to the cylinder assembly or hydraulic system. Such stops shall be of the solid metal to metal type.(2) Traveling sheaves of roped hydraulic elevators shall be guided in metal guides. Sheave frames, where used, shall be of structural or forged steel having an elongation of not less than 14% in a length of two inches and shall be designed and constructed with a factor of safety of at least eight. A single continuous strap shall not be used for the sheave frame.(3) Cylinders, valves, piping, connections and tanks shall conform to the requirements of 524 CMR 35.00: Safety Code for Elevators and Escalators A17.1-2013 and the Massachusetts Modifications of That Code. Piston rods of roped hydraulic elevators shall conform to the following: (a) Piston rods in compression shall be designed and constructed in accordance with the applicable formula for plungers, (b) Piston rods in tension shall be designed and constructed in accordance with the following formula: W = 7500A
Where: W =Allowable gross load, pounds applied to piston rod
A = Net cross sectional area at root of threads in square inches
(c) Means shall be provided to prevent eccentric loading on piston rods and to equalize loading on piston rods where two or more are used.Amended by Mass Register Issue 1366, eff. 6/1/2018.