Machine SafetyChapter 296-806, WAC |
Effective Date: 01/01/05 |
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Conveyors |
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GENERAL REQUIREMENTS FOR CONVEYORS
Follow these requirements for conveyors
You must
- Construct, operate, and maintain all conveyors according to this chapter and the American National Standards Institute (ANSI) B20.1-1957.
- Make sure all new conveyors constructed after
January 1, 2005, meet the requirements of the American Society
of Mechanical Engineers (ASME)
B20.1-1996.
Provide emergency stops on conveyors
You must- Make sure each conveyor has an emergency stopping device such as an emergency stop button, pull cord, or similar device.
- Make sure each emergency stopping device meets
all of the following requirements. They must:
- – Stop the conveyor a safe distance from the hazard
- – Be easily identified
- – Directly control that conveyor
- – Require a manual reset
- – Not be overridden from another location
- – Not require other equipment to be stopped in order to stop the conveyor
- Make sure where there's the possibility of
an employee falling onto a conveyor, that the emergency stopping
device for conveyors feeding or dumping into a hazardous machine
such as a barker, saw, hog, or chipper is at least one
of the following:
- – Under the continuous control of
an operator who can't fall onto the conveyor and has full
view of the material entrance
or - – Located where it can be reached from a sitting position on the conveyor where it feeds or dumps into the hazardous machine
- – Under the continuous control of
an operator who can't fall onto the conveyor and has full
view of the material entrance
Label conveyor controls
You must- Clearly label the function of each conveyor control.
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Note:
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Prohibit riding on conveyors
You must- Prohibit employees from riding on conveyors.
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Provide safe access to conveyors
You must- Provide a way to safely inspect and maintain conveyors located more than 7 feet from the floor.
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Provide backstop or anti-runaway devices on incline, decline, or vertical conveyors
You must- Make sure all incline, decline, or vertical conveyors use backstop or anti-runaway devices when there's a danger of conveyor reversal or runaway.
Make only safe alterations to conveyors
You must- Make sure, when making conveyor alterations, that you don't affect safety characteristics such as emergency stop controls, guards, or the incline of the conveyor, if such changes would create a danger to workers.
Inspect and replace worn conveyor parts
You must- Carefully inspect and replace any conveyor part that shows signs of significant wear before it becomes a hazard.
Follow these requirements for replacing conveyor parts
You must- Make sure replacement conveyor parts are equal to or exceed the manufacturer’s specifications.
Follow these requirements for spill guards
You must- Install protective or spill guards wherever
conveyors pass next to or over working areas or passageways.
- – These guards must be designed to catch and hold any materials that may become dislodged or fall off.

- For specific requirements when conveyors
pass over emergency exit routes, see Exit Routes,
WAC 296-800-310.
Provide pedestrian overpasses for conveyors
You must- Provide a pedestrian overpass covering the
full width of a passageway if one of these
conditions exists:
- – The working strand of a conveyor crosses within 3 feet of floor level
- – Workers must step over the strand and trough at or below floor level
- Provide a pedestrian overpass where workers can't pass under the conveyor safely
- – The sides of the crossing platform
must have standard railings if one of the
following exists:
- The overpass is more than 4 feet high
- The conveyor feeds a dangerous machine such as saws, chippers, hogs, or galvanizing tanks
- For guardrail requirements see Railing, Toeboards, and Cover Specifications, WAC 296-24-75011.
Guard openings to hoppers and chutes
You must- Guard all openings to hoppers, chutes, and
elevator-type conveyors to prevent workers from:
- – Falling or stepping into them
- – Making any kind of bodily contact with conveyors

Note:
- Grating provided at floor level with no openings larger than 2 inches (50mm) that's strong enough to withstand any load of personnel or trucks that may be imposed upon it, is acceptable guarding.
You must
- Do all of the following when
dumping operations use chutes or hoppers that are flush with
the floor and their use can't be guarded:
- – Place a temporary guardrail around ground or floor-level hoppers when dumping operations are not in progress.
- – Post warning signs in a conspicuous location alerting personnel to the presence of an open pit in order to protect employees when dumping operations are in progress.

- For guardrail requirements see Railing, Toeboards, and Cover Specifications, WAC 296-24-75011.
Install guideposts
You must- Install guideposts to direct employees driving trucks, loaders, or other equipment to the pit, hopper, or chute.
BELT CONVEYORS
Guard nip points on belt conveyors
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Illustration
420-1
RETURN BELT IDLERS

- Place nip point guards at all
of these points:
- – Where the belt wraps around the pulley
- – At terminals, take-ups, and snub rollers where the belt changes directions at transfers and deflectors
- – At the discharge end
- – At other points where workers may be injured by nip or shear points

Note:
- The practice of applying a belt dressing or other foreign material to a rotating drive pulley or a conveyor belt is hazardous and should be avoided.
Install emergency stop controllers on overland belt conveyors
You must- Install permanent emergency pull cords or
similar emergency stop controllers at points where workers are
normally stationed along overland belt conveyors.

Note:
- Personnel that patrol overland belt conveyors may use portable emergency stop controllers instead of permanently installed pull cords and push-button stations.
Install belt conveyor overpasses
You must- Install a pedestrian overpass or underpass
along the sides of long overland belt conveyors, where there's
the most foot traffic.
- – The distance between overpasses shouldn't exceed 300 meters or 1,000 feet.
CHAIN CONVEYORS
Safeguard chain conveyors
You must- Provide safeguards for drive, tail, and idler sprocket pulleys where the chain creates a nip or shear point
Guard return strands on chain conveyors
You must- Provide a way to catch and support the ends of a chain that break over a passageway.
- Provide a strong enough trough to carry the weight from a broken chain on conveyors when return strands operate within 7 feet of the floor.
Guard chain conveyors that are used as a transfer mechanism
You must- Guard chain conveyors whose moving chains
can't be enclosed without impairing their function by one
of the following methods:
- – Distance as required in Make sure safeguarding by distance meets these requirements, WAC 296-806-20056
- – Personnel barriers
- – Warning signs where personnel barriers aren't practical

Note:
- Chain conveyors with moving chains
that can't be enclosed include those:
- – Mounted within another conveyor
- – Raised and lowered as a transfer mechanism
ELEVATOR CONVEYORS
Prevent material from falling off of elevator conveyors
You must- Install strong guards, screens, or barricades to prevent material from falling in any direction into the shaft way of elevator-type conveyors, except at loading and unloading areas.
- Install automatic shaft way gates or suitable barriers at each floor level where material is loaded or unloaded.
INCLINED RECIPROCATING CONVEYORS (SHAKERS)
Provide protection where employees must load shakers
You must- Provide standard guardrails or snap chains
along loading sides of the shaker where personnel must load
or unload material.
- – Snap chains must be at least 39 inches high at their lowest point.
- Make sure controls are located so the conveyor can't be started by an employee on the moving part of the conveyor.
Provide grating over silo and bunker openings for shuttle conveyors
You must- Provide grating with openings to match the
size of the material being discharged into silos or bunkers.
Make sure openings are:
- – Small enough so that workers can't fall through
- – Protected by other effective means if the material size requires openings large enough for a worker to fall through
MOBILE CONVEYORS
Guard wheels and rails on mobile conveyors
You must- Install sweeps in front of the nip points created by the wheels and rails to deflect objects that could derail the conveyor.
Prevent hazardous motion on mobile conveyors
You must- Make sure mobile conveyors have at
least one of the following to prevent hazardous motion:
- – Brakes
- – Rail clamps
- – Other position-locking devices
- Provide limit switches that will stop
travel when exceeding the design limits of
rail-mounted mobile conveyors - Provide rail stops to keep the conveyor from traveling past its designed end location.
Provide a detector for mobile conveyors
You must- Provide a detector to stop conveyor movement when the operation creates a danger of running into a stockpile or other obstacle.
Provide safe access on mobile conveyors
You must- Make sure that access stairways, ladders, and platforms are designed and located to avoid the shear or nip point hazards of the conveyor and moving machinery.
