Varco HT-Tong HT100, User Manual

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8
Appendix
HT-Tong
8-27
Appendixes
Summary of risk assessment
Identified potential hazard Point of failure Result
Chain/cable/pull line
overtensioned
Breaking of chain/cable/pull line
This may cause the tong rotate uncontrollable,
hitting everything in it's way.
Chain/cable/pull line
overtensioned
Breaking of chain/cable/pull line Cable releases energy, flying all over the place
Pulling too hard relative to tong
(wrong tong being used)
Failing or breaking tong.
The tong being used may break because of too
small tong utilized, resulting in tong debris
flying around all over the place.
Pinch points due to other
devices in work area of tong
(e.g. back up tong on the same
level))
Device collides with HT-tong Crushing hand/fingers/limps/body
Applying tong too low to floor No control over tong(s) Crushing hands/limps
MU Tong too close to Back Up
tong
Dangerously close Crushing / shearing hands/limps
Tong line connection failure
Breaking of pin / lever/snub line
saver This may cause the tong rotateuncontrollable,
hitting everything in it's way.
Failing tong line retention Breaking tong line retainer bolt
This may cause the line to break free from the
tong when tensioning, resulting in not being
able to apply torque
Cable releases energy, flying all over the place
Snub line saver break Breaking parts/bolts/u-clamp
This may cause the tong rotate uncontrollable,
hitting everything in it's way
Missing nameplate Not using proper size tong
The tong being used may break because of too
small tong utilized, resulting in tong debris
flying around all over the place
Breaking lever
Not checked during inspection
schedule (MPI)
Tong debris may fly around all over the place
Breaking / missing hanger bolt
Not checked during inspection
schedule
Tong may drop to the floor
Breaking hanger
Not checked during inspection
schedule
Tong may drop to the floor
Missing / loose hanger
adjustment screw Not checked during inspection
schedule
Tong may be hard to handle during run
Missing/failing balancing screw
bolt Not checked during inspection
schedule
Tong may drop to the floor
Breaking suspension ring
Not checked during inspection
schedule
Tong may drop to the floor
Missing grease nipples
No proper lubrication of hinge
pins results in worn out bores/
pins
Tong may be hard to handle during run
Tong pins may break due to wear
Tong parts may break due to wear
Breaking jaws or latch
Not checked during inspection
schedule (MPI)
Tong debris may fly around all over the place.
Slipping dies Inserts worn out.
Tong may slip and make unexpected
movement
Coupling may not be made up properly,
resulting of loosing pipe
Missing handle bolts Loose nuts Pinch points as operator will grab other parts
Missing protective hose around
handle bolts
Worn hose May cause uncomfortable situation
Missing nuts of hinge pin(s)
Not checked during inspection
schedule May cause dangerous situation as hinge pin
failure may occur
Missing hinge pin(s) Missing nut/dowel pin Not being able to use tong
Missing dowel pins of hinge pin
nuts Not checked during inspection
schedule May cause dangerous situation as hinge pin
failure may occur
Missing/failing springs
Not checked during functional
check
Latch may not close easily