2.4.5
Automatic Shutoff Valve
Provide automatic shut-off valve in oil supply line as close to cylinder
inlet as possible. Provide threaded pipe connections to the valve. When
there is ten percent drop in NO-LOAD operating pressure, activate the
automatic shut-off valve. When activated, device shall immediately stop
descent of elevator and hold elevator until lowered by use of manual
lowering feature of valve. Arrange manual lowering feature of automatic
shut-off valve to limit descending speed of elevator to 0.10 mps 20 fpm.
Provide exposed adjustments of automatic shut-off valve with means of
adjustment sealed by certified elevator inspector after being set to
correct position and tested in accordance with Paragraph Automatic Shutoff
Valve Tests.
2.4.6
Cylinder Well System
The cylinder well system shall consist of a well casing and a liner.
2.4.6.1
Well Casing
Drill well for hydraulic cylinder, providing adequate depth, as indicated.
Line well with steel casing with minimum wall thickness of 6 mm 0.25 inch,
and minimum inside diameter of not less than 125 mm 5 inch larger than PVC
liner maximum outside diameter, including cap and couplings. Close bottom
of well casing with steel plate at least twice as thick as casing wall
thickness, welded continuously all around, prior to insertion into well, or
close well casing bottom by plugging with minimum of 150 mm 6 inch of
concrete, embedding casing bottom at least 50 mm 2 inch but not more than
100 mm 4 inch into the wet concrete. Install cylinder well casing not more
than 25 mm 1 inch out of plumb over entire length. Backfill the well
outside of the casing with fine, dry, salt-free sand, as required to
maintain casing straight and plumb, or backfill with bentonite grout if
more than one water-bearing strata are penetrated by well. Maintain well
casing pumped dry throughout remaining installation of elevator.
2.4.6.2
PVC Liner
Provide Schedule 80 PVC pipe liner with bottom cap and couplings; joints
sealed watertight using PVC pipe manufacturer's recommended adhesive or
heat welding methods. Liner inside diameter not less than 76 mm 3 inch
larger than elevator cylinder maximum outside diameter. Set PVC liner into
well casing, centered and plumb. Securely locate PVC liner bottom end
within well casing with fine, dry, salt free sand.
2.4.6.3
Pressure Test
Install pressure test cap onto PVC liner, equipped with at least: safety
relief valve set to relieve at 205 kPag 30 psig; 114 mm 4.5 inch diameter
dial pressure gage scaled for 0 to 690 kPag 0 to 100 psig and calibrated to
0.5 percent accuracy; and an air pressure admission throttling and shutoff
valve. Perform air pressure test by slowly admitting dry compressed air to
pressurize PVC liner to 205 kPag 30 psig. Shut off air supply at
throttle/shutoff valve, disconnect compressed air source, observe and
record air pressure in PVC liner every 5 minutes for not less than 30
minutes. Do not allow liner to drop in air pressure in excess of one kPag
0.5 psig over the 30 minute test period. Perform test in presence of the
Elevator Inspector. Upon satisfactory completion of pressure test, remove
test cap and dry interior of PVC liner. Upon failure of test, remove,
SECTION 14240
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