§ 7.76. Hydraulic passenger elevators.
(a) The valve chambers and cylinders of all hydraulic passenger elevators shall be equipped with means for removing any accumulation of air.
(b) New hydraulic and oil-electric elevators shall be equipped with supply and discharge pipes of sufficient area as to be unaffected by the operation of any other elevator on the same system. Supply tanks shall be of sufficient capacity to provide for an adequate liquid reserve to prevent the entrance of air or other gas into the system and to permit a travel of at least three feet beyond the upper terminal landing. Such permissible minimum liquid level shall be clearly indicated.
(c) In new installations, structural steel guides shall be provided for every crosshead having a travel in excess of 15 feet; structural steel hangers shall be provided for traveling sheaves when the travel of the sheaves exceeds l5 feet. In existing installations, structural steel guides shall be provided for every crosshead when necessary to prevent swaying of the crosshead.
(d) Each pump shall be equipped with an automatic bypass. Each pump connected to pressure tanks of hydraulic passenger elevators shall be equipped with one or more water relief valves, which shall be of ample capacity to prevent a pressure in excess of the maximum allowable pressure of the pump or tank. There shall be no shutoff valve between the water relief valve and the pump or tank which it protects. The discharge from the water relief valves shall be conducted to the discharge tank or to the pump suction.
(e) Pressure tanks of hydraulic passenger elevators shall be equipped with a water relief valve of sufficient capacity to discharge the pump delivery without an increase of more than l5 pounds above the allowable working pressure of the tank. If, in the judgment of the Department, the water relief valve on the pump will provide sufficient protection, the water relief valve for the pressure tank may be omitted.
(f) In new installations, the car platform of a direct plunger passenger elevator shall be securely fastened to the head of the plunger by not less than four 5/8 inch diameter bolts or by any other means whereby a factor of safety of four shall be maintained provided such alternate means be submitted to the Industrial Board for approval. When the plunger consists of more than three sections and the elevator car is equipped with counterweights, the car platform shall be further secured to the bottom section of the plunger by a noncorrosive cable inside of such plunger.
(g) When a new elevator car is equipped with counterweights the plunger head shall be constructed of steel or wrought iron material.
(h) The plunger of every uncounterweighted hydraulic elevator having a travel in excess of 75 feet shall be equipped with a traveling guide or follower which will remain midway between the car and the stuffing box throughout the entire length of travel.
(i) All pressure tanks for hydraulic passenger elevators and pipe materials other than threaded heavy-duty metal pipe shall first be approved by the Board.
(j) Each hydraulic passenger elevator shall be provided with automatic limit stops arranged to bring the car to a gradual stop at terminal landings independent of the car-controlling mechanism. For plunger elevators having a car speed of 100 or less feet per minute, the automatic limit stop may be an independent cable with button stops on the car, such cable to be connected to the main operating valve. For horizontal or vertical cylinder machines having a car speed of 100 or less feet per minute the automatic limit stop may be an independent cable actuated by the traveling crosshead and connected to the main operating valve. Each hydraulic passenger elevator having a car speed more than 100 feet per minute shall be provided with independent automatic stop valves.
(k) The capacity of operating and stop valves shall not be more than will permit the operation of the car with the maximum load at the allowable rate of speed.
(l) Piston rods shall be thoroughly examined by an approved inspector at least once every three years.
(m) Cylinder or plunger passenger elevators in which the motive power is steam, gas, or air shall, when possible, come within the requirements for hydraulic passenger elevators.
(n) Existing installations of every type of hydraulic elevator shall be changed to meet the requirements for new installations, when necessary for safe operation, if ordered by the Department.
(o) Electrically controlled hydraulic and oil electric elevators shall be equipped with two magnetic switches both of which shall be closed to complete the motor circuit unless there is a second control means (for example, a valve) in which case only one such magnetic switch is required in the motor control circuit.
(p) Each hydraulic passenger or freight elevator shall be equipped with an approved electrically-controlled normally closed valve, operating devices and control equipment, including anti-creep leveling devices, and terminal stopping devices.
(q) When electrically-operated valves are installed to replace existing mechanically-operated valves, for rated speeds of more than 100 feet per minute, existing terminal stopping devices, consisting of an automatic stop valve independent of the electric control valve and operated by the movement of the car as it approaches the terminals, where provided, shall be retained.
(r) Anti-creep leveling devices shall maintain the car within three inches of the landing from any point within the interlock zone irrespective of the position of the hoistway door. For electric hydraulic elevators, it is required to operate the car only in the ‘‘up’’ direction. For maintained-pressure hydraulic elevators, it is required to operate the car in both directions, and shall operate in conjunction with an approved electrically-controlled, valve-operating system. The closing of this control device shall not be dependent on the completion or maintenance of an electric circuit for the interruption of the power. However, movement of the car in response to the anti-creep leveling device shall be prevented by the operation of either the stop switches in the pit or on the car top or by the electric contacts provided for top or side emergency exits. This exception shall apply to all installations for which a permit has been issued subsequent to the effective date of this exception.
(s) Prior to the approval of the electrical control valve and related parts for water hydraulic elevators, the manufacturer of each control valve to be approved shall submit the following to the Board:
(1) Two complete sets of assembly and detail drawings of the control valve and related parts.
(2) All drawings shall be to scale.
(3) All pertinent information as to materials and clearances.
(t) Devices approved pursuant to subsection (s) shall be inspected and tested in the field under maximum operating conditions by a Department inspector.
Source The provisions of this § 7.76 amended through January 27, 1978, 8 Pa.B. 251. Immediately preceding text appears at serial page (15209).
Cross References This section cited in 34 Pa. Code § 7.295 (relating to hydraulic freight elevators).
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