Appendix
69
GLOBAL
INDUSTRIES, INC.
Drag Conveyors
10230011
2016-06-14
A
CHAIN FAILURE
Check if the chain is worn out. By rotating the link
to expose the pin surface, wear can be seen. The
example below is an example of a worn out pin.
Wear can be accelerated by both corrosion and
abrasion. Corrosion can be seen when there is a
great deal of pitting and rust. Abrasive conditions
usually leave a smooth surface but with many
scratches, particularly on the wearing surface of
the pin. Also, as a chain wears it grows in length,
sometimes called elongation. Checking the length
of the chain is a good way of checking how much
wear has occurred.
See below the MFS/YORK/STORMOR chain table
for conveyors. Worn out measurements are based
on 3.5% elongation at a 100 lb [45 kg] load.
B
TENSILE FAILURE
A tensile failure occurs when a single pull on
the chain is great enough to pull the chain
apart. Normally the barrel splits open as shown
in the example at the top of the next page.
Sometimes it is accompanied by elongated
holes and turned pins. A tensile failure
normally occurs under a severe overload
when a chain load approaches (5) times what
is normally anticipated. However, it may also
occur when the chain is so excessively worn
that even normal loads cause breakage.
wear
Chain
Number of
Pitches^ in
(1) New Role
New
Worn Out
81X
48
125”
[3,175 mm]
129”
[3,277 mm]
WH124
30
120”
[3,048 mm]
124”
[3,150 mm]
WH132
20
120”
[3,048 mm]
124”
[3,150 mm]
New and Worn Chain Lengths
(length of 50 links)
^ 1 Pitch = Chain, Pin Center to Pin Center Distance