2.9.15
Coal Valve
Dusttight and drip proof of the double ladder rack-and-pinion type sized as
indicated for each valve. Valve shall be capable of closing through a
standing coal column. Valve opening shall be full size with no bridges,
internal braces, or other barriers.
2.9.15.1
Valve Body
Not less than 6 mm 1/4 inch thick formed 410 stainless steel with heavy 19
mm 3/4 inch thick flanges. Continuously weld joints in contact with coal
both inside and out and grind smooth. Valve body shall have dusttight
steel gate assembly cover with molded gasket for removal of gate without
removing the coal valve. Provide a minimum of two dusttight poke holes
with rigid covers and molded gaskets.
2.9.15.2
Valve Gate
Drip proof and siftproof of 10 mm 3/8 inch thick steel plate with an 11
gage (3.04 mm0.1196 inch) 410 stainless steel liner.
Support gate by ball
bearing rollers with 16 gage (1.52 mm 0.0598 inch) stainless steel shells
equipped with felt grease seals and stainless steel grease retainers.
Provide rollers with grease fittings extended through the valve body for
pressure lubrication. Design gate so that supporting rollers, racks, and
pinions are located completely out of the coal stream. Racks shall be cold
formed and self cleaning, with stainless steel self cleaning pinions
located over racks for positive tooth engagement.
2.9.15.3
Operating Shaft
Mount operating shaft in ball bearings with felt seals, stainless steel
shells, stainless steel grease retainers, and grease fittings. Provide
handwheels with proper finger clearance or pocket sheaves with heavy
hot-dipped galvanized chain and chain guard as indicated. Handwheels and
sheaves shall be not less than 457 mm 18 inches in diameter.
Provide
valves with mechanical type position indicator consisting of large pointer
and legend to indicate the position of the valve gate.
2.9.15.4
Electric Motor Operators
Provide motor operators where indicated and capable of remote operation
from the coal handling control panel. Operator shall consist of totally
enclosed, fan cooled, high torque, [_____] volt, [_____] phase, 60 Hz motor
as specified under paragraph entitled "Motors and Drives" in this section
with reduction gear, clutch and limit switches. Motor horsepower shall be
as recommended by the manufacturer. Provide motorized valves that have
manual operators, with fail-safe interlocks that make manual operation
impossible while motor is operating.
2.9.16
Track and Reclaim Hopper Valves
Dusttight, double rack and pinion type, with water collecting trough.
Valve shall have inlet opening not less than [_____] by [_____] mm inches
in the direction of gate travel with a larger outlet opening.
Inlet and
outlet shall be flanged and constructed of mild steel.
2.9.16.1
Valve Body
Not less than 10 mm 3/8 inch thick mild steel continuously welded both
SECTION 15502N
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