Attachment 1: Specifications - Metropolitan Washington Airports ...

DCA TERMINAL A IMPROVEMENTS (NEAR TERM)10 AUGUST 2012
TASK ORDER 03: LOBBY IMPROVEMENTS – PKG 4 -CURBSIDE CHECK-IN
RONALD REAGAN WASHINGTON NATIONAL AIRPORT
PROJECT DT1203
3. End Drive Power Pulleys:
a. Power pulleys for end-type drives or power take offs shall be lagged with a
minimum 3/8” thick vulcanized lagging of 50-60 durometer, and be 6” diameter
(minimum) trapezoidal faced and equipped with taper-lock hubs and 1-7/16”
minimum diameter C.R.S. shafts mounted in eccentric locking-type precision and
ground flange ball bearing units. End-type drive units shall not be used for
conveyors exceeding 25’ in length.
4. Motorized Pulley: Not Used.
5. Head and Tail Pulleys:
a. All non-powered head and tail pulleys shall be of steel, trapezoidal faced, equipped
with taper-lock type hubs and 1-7/16” minimum diameter AISI 1018 C.R.S. shafts
mounted in eccentric locking type precision and ground flange-type ball bearing
units. All head and tail pulleys shall be 6” in diameter minimum x 10-gauge wall.
Pulleys shall be of a single piece steel construction and have steel end discs
attached to the rim by continuous welding. Slider bed shall be arranged to keep the
gap between the end section and the end pulley to a minimum. All head and tail
pulleys used for belt tracking shall be equipped with jacking bolts to facilitate
adjustment.
b. All pulleys are to be statically balanced when operating speeds exceed 200 rpm,
and dynamically balanced when speeds exceed 500 rpm. Rollers of eccentric
material, such as standard pipe, are to be statically balanced when operating speeds
exceed 200 rpm, and dynamically balanced when speeds exceed 400 rpm. Rollers
made of seamless tubing may be used without balancing at speeds up to 1000 rpm,
providing straightness is held to close limits and excessive welding flash is not
present; for speeds in excess of 1000 rpm, dynamic balance is required.
6. Return Idlers:
a. The return rollers shall be a minimum of 2-1/2” diameter, 12-gauge steel equipped
with an 11/16” hex axle.
b. All hex shaft return idler rollers shall be equipped with sealed, permanently
lubricated, caged, semi-precision type ball bearings. Return idlers shall be located
on centers not to exceed ten feet, with spacing being reduced in areas where
belting may drag against the floor or conveyor structure. The shafts shall be
mounted to the conveyor bed with adjustable retainers for proper belt tracking.
7. Snub Pulleys:
a. All snub pulleys shall be a minimum of 3-1/2” in diameter, steel, trapezoidal faced,
and equipped with taper-lock type hubs and 1-7/16” minimum diameter C1018
C.R.S. annealed and machined steel shafts mounted in eccentric locking type
precision and ground flange-type ball bearing units. All snub rollers used for belt
tracking shall be equipped with jacking bolts to facilitate adjustment.
8. Take-Ups:
BAGGAGE HANDLING EQUIPMENT 34 77 16 - 37