Environmental Temperatures and Points of Concern
Temperatures
Chain Selection
Caution
• Under -20°F or lower conditions, ASME/ANSI 304 stainless steel chains and 600 series stainless steel chains are suggested. • Carbon chains are not suggested. The chain should be selected on the basis of the corrected working load, below.
(1)Low temperature embrittle- ment may occur on link plates of carbon steel chain. (2)Freezing of lubricant. (3)Rust due to condensation. (4)Seizure due to freezing.
-60° F
-20° F
-20° F
15° F 140° F 300° F
Special lubrication is required.
The chain should be selected on the basis of the corrected working load, below. Selection of the next larger pitch chain over the originally selected one is suggested. ASME/ANSI 304 stainless steel chain and ASME/ANSI 600 series stainless steel chain are suggested.
(1) Excessive wear due to
decrease of hardness of pin and bushing.
300° F
480° F
(2)Poor lubrication due to deterioration of lube.
480°F
Table V: Corrected Working Load
Temperature
Corrected Working Load
-20° F ~ -4° F
(Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog) (Max. allowable load in catalog)
x 0.25
-4° F ~ 15° F
x 0.3 x 1.0
15° F ~ 300° F
300° F ~ 390° F 390° F ~ 480° F
x 0.75
x 0.5
2. In wet conditions: When chain is exposed to water, e.g., in a sterilizer or water screen, excessive wear due to insufficient lubrication and rust may shorten chain life. In these cases, a larger chain size provides less bearing pressure and stainless steel or plated chain will provide rust prevention. 3. In corrosive conditions: When chain is exposed to an acidic or alkaline solution or operated in a corrosive atmosphere, excessive wear may occur due to chemical corrosion on the chain parts in addi- tion to mechanical wear. Hydrogen embrittlement may also occur in an acidic atmosphere. Roller chain is more easily affected by acid than alkali. In special cases, electro-chemical corrosion may occur on the chain due to sea or mine water. Refer to the
table on page A-60 “Corrosion Resistance Guide”, for the corrosion resistance of stainless steel.
4. In dusty conditions: When conveyor chain is operated in dusty conditions, i.e., in the presence of coke, metal powder, and sand, the chain wears very quickly because foreign material gets between the parts of the chain and also the engaging surfaces of the sprocket teeth and chain. In such cases, select a larger chain size to reduce the bearing pressure or choose a chain especially designed for high wear resistance. The foregoing information is intended to provide general guidelines for conveyor chain selection. Please consult with U.S. Tsubaki for specific application problems.
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