Working Formulas
Use these calculations to custom-choose your product needs.
Code of Symbols
Belt Length
Belt Length
Belt Speed
| B | Sine of Angle of Incline | G2 | Load per Hour (in lbs.) | C | Center to Center distance (in Inches) |
| HP | Horsepower | D | Diameter or Drive Pulley (in inches) | K | Drive Factor (See Table #2) |
| d | Diameter of Tail Pulley (in inches) | L | Belt Length (in inches) | E | Effective Tension (in lbs.) |
| M | Belt Weight (See weight in lbs. PIW for particular belt specification)(overall length, not center to center) | E1 | Slack Side Tension (in lbs.) | P | Product Weight (in lbs.) |
| E2 | Tight Side Tension (in lbs.) | RPM | Revolutions per Minute | F | Coefficient of Friction (See Table #1) |
| S | Speed (Feet Per Minute) | G1 | Load Per Sq. or Cu. Ft. (in lbs.) | T | Operating Tension PIW (in lbs.) |
| W | Belt Width (in inches) | ||||
Table #1
Coefficient of Friction “F” |
||
| Belt | Steel or Aluminum | Metal Rollers |
|---|---|---|
| FS pulley side | .30 to .35 | .10 to .15 |
| Bare Duck or BB side | .20 to .25 | .10 to .15 |
| Cover on pulley side | .50 to .55 | .10 to .15 |
| Note: The highest figure is the most conservative | ||
Belt Length
when pulleys are approximately the same size
| L = | D + d | x 3.1416 | + 2C |
| 2 |
Belt Length
when one pulley is much larger than the other (at least 3 or more times larger)
| L = | D + d | x 3.1416 | + 2C + | (D – d)2 |
| 2 | 4C |
Belt Speed
in Feet Per Minute
S = D x RPM x .2618 x 1.021
Load on Belt
Load On Belt
Belt Weight
Horsepower
Load on Belt
at one time when load is known (per square foot or per cubic foot basis)
P = G1 x C (in ft.) x W (in ft.)
Load on Belt
at one time when load is known (by lbs. per hour or tons per hour)
| P = | G2 | x C (in ft.) |
| S x 60 (minutes) |
Belt Weight
L (in ft.) x (Belt Weight PIW x W)
Horsepower
to drive horizontal belt conveyors
| HP = | F x S x (P + M) |
| 33,000 |
Horsepower
Effective Tension
Slack Side Tension
Tight Side Tension
Horsepower
to drive inclined belt conveyors
| HP = | (P x B) + (P + M) x F x S |
| 33,000 |
Effective Tension
E = F x (P +M)
Slack Side Tension
additional tension required to prevent slippage on drive pulley
E1 = E x K
Tight Side Tension
total tension required to move belt and load
E2 = E + E1
Operating Tension
Effective Tension
Operating Tension
determines working strength of belt to handle job on per inch of width basis
| T = | E2 |
| W |
Length of Belt in a Roll
approximate only
| L = | D2 – 100 |
| 15.3T |
| D | Diameter in inches |
| T | Thickness in inches |
| L | Length in Feet |
| (approximate) |
Code of Symbols
Belt Length
| B | Sine of Angle of Incline | G2 | Load per Hour (in lbs.) | C | Center to Center distance (in Inches) |
| HP | Horsepower | D | Diameter or Drive Pulley (in inches) | K | Drive Factor (See Table #2) |
| d | Diameter of Tail Pulley (in inches) | L | Belt Length (in inches) | E | Effective Tension (in lbs.) |
| M | Belt Weight (See weight in lbs. PIW for particular belt specification)(overall length, not center to center) | E1 | Slack Side Tension (in lbs.) | P | Product Weight (in lbs.) |
| E2 | Tight Side Tension (in lbs.) | RPM | Revolutions per Minute | F | Coefficient of Friction (See Table #1) |
| S | Speed (Feet Per Minute) | G1 | Load Per Sq. or Cu. Ft. (in lbs.) | T | Operating Tension PIW (in lbs.) |
| W | Belt Width (in inches) | ||||
Table #1
Coefficient of Friction “F” |
||
| Belt | Steel or Aluminum | Metal Rollers |
|---|---|---|
| FS pulley side | .30 to .35 | .10 to .15 |
| Bare Duck or BB side | .20 to .25 | .10 to .15 |
| Cover on pulley side | .50 to .55 | .10 to .15 |
| Note: The highest figure is the most conservative | ||
Belt Length
when pulleys are approximately the same size
| L = | D + d | x 3.1416 | + 2C |
| 2 |
Belt Length
Belt Speed
Belt Length
when one pulley is much larger than the other (at least 3 or more times larger)
| L = | D + d | x 3.1416 | + 2C + | (D – d)2 |
| 2 | 4C |
Belt Speed
in Feet Per Minute
S = D x RPM x .2618 x 1.021
Load on Belt
Load on Belt
Load on Belt
at one time when load is known (per square foot or per cubic foot basis)
P = G1 x C (in ft.) x W (in ft.)
Load on Belt
at one time when load is known (by lbs. per hour or tons per hour)
| P = | G2 | x C (in ft.) |
| S x 60 (minutes) |
Belt Weight
Horsepower
Belt Weight
L (in ft.) x (Belt Weight PIW x W)
Horsepower
to drive horizontal belt conveyors
| HP = | F x S x (P + M) |
| 33,000 |
Horsepower
Effective Tension
Horsepower
to drive inclined belt conveyors
| HP = | (P x B) + (P + M) x F x S |
| 33,000 |
Effective Tension
E = F x (P +M)
Slack Side Tension
Tight Side Tension
Slack Side Tension
additional tension required to prevent slippage on drive pulley
E1 = E x K
Tight Side Tension
total tension required to move belt and load
E2 = E + E1
Operating Tension
Length of Belt in a Roll
Operating Tension
determines working strength of belt to handle job on per inch of width basis
| T = | E2 |
| W |
Length of Belt in a Roll
approximate only
| L = | D2 – 100 |
| 15.3T |
| D | Diameter in inches |
| T | Thickness in inches |
| L | Length in Feet |
| (approximate) |