2.4.2
Hydraulic Controls and Equipment
Provide electrically operated "UP" valve, constant velocity "DOWN" valve,
"UP" and "DOWN" leveling valves, "BYPASS UPON STARTING" valve, check valve,
vacuum relief valve, automatic shutoff (rupture) valve, safety relief
valve, manually operated lowering valve, and scavenger pump unit.
2.4.2.1
Manual Shutoff Valves
Provide 1/4 turn ball valve rated at 2 MPa 300 psi at elevator hydraulic
pump suction inlet if pump is mounted outside the oil reservoir and the
suction line exits the reservoir below the maximum oil level in the
reservoir. Provide 1/4 turn ball valve rated at 4 MPa 600 psi at elevator
pump discharge line in the machine room and in the oil supply line next to
and on the pump side of the automatic shutoff valve in the pit.
2.4.2.2
Manual Lowering Valve
Limit car descending speed under manual operation to 0.10 mps 20 fpm.
Provide rigid plastic red tag for valve identification, inscribed "MANUAL
LOWERING VALVE."
2.4.2.3
Pump Discharge Strainer
Provide strainer in pump discharge to prevent foreign materials from
entering control system and cylinder-plunger unit (jack).
2.4.2.4
Provide blowout-proof muffler, containing pulsation-absorbing materials in
oil line between pump unit and jack.
2.4.2.5
Pressure Switch
Where cylinders are installed with top of cylinder above top of oil
reservoir, provide pressure switch in oil line between cylinder and
electric lowering valve(s) to prevent operation of lowering valve(s) unless
positive pressure exists at top of cylinder.
2.4.2.6
Scavenger Pump Unit
Provide a scavenge oil reservoir, an electrically operated oil transfer
pump, scavenge oil lines, a strainer, and pump controls. Connect the
scavenge oil reservoir to the elevator cylinder between the plunger packing
area and the plunger drip (wiper) ring, to capture the oil leaking by the
plunger pressure packing. Provide a vacuum relief valve. Connect the
scavenge oil pump suction to the scavenge oil reservoir and the strainer,
and the discharge to the elevator oil reservoir. Provide a scavenge oil
reservoir level switch to control the scavenge oil pump. Scavenger pump
shall operate independently of elevator hydraulic fluid pressure. Provide
a manual-reset pit flood switch to prevent pump operation if pit is
flooded. Anchor pump and oil reservoir to the pit floor.
2.4.2.7
Piping and Accessories
Provide ASTM A 53/A 53M or ASTM A 106/A 106M, Schedule 80, black steel
piping with ASME B16.9 and ASME B16.11 fittings. Extend Schedule 80 piping
from the pump control valve body, inside the pump unit, to the hydraulic
cylinder in the hoistway. Provide dielectric union at each end of the
SECTION 14240
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