Conveyor Belt Load Support

Load Support

To prevent longitudinal creasing of the conveyor belt at troughing roll junctures (angle formed by the horizontal center roll and the angled troughing rolls), the belt carcass must have body to resist being squeezed between the rolls by the load weight.

First determine Material Weight (MW):

MW = 33.3 TPH/3 or MH = Total Load (lbs)/L

The value in the following tables F₁ and F₂ are limits for the ply ratings given:

Table F₁Guide for Load Support at Troughing Idlers (Any Angle)

Multiple Ply Fabric	Material Weight Factors (MW) Plies						Belt Width
Multiple Ply Fabric	3	4	5	6	7	8	Belt Width
MP 35	10 10 10 10	40 25 10 10	80 60 40 30	120 100 80 60	190 160 120 90	280 235 190 145	up to 36” 37 - 48” 49 - 78” 79 - 96”
MP 43	20 20 20 20	50 40 20 20	100 80 50 45	150 130 100 60	240 200 150 110	370 300 240 170	up to 36” 37 - 48” 49 - 78” 79 - 96”
MP 50	30 30 30 30	70 50 30 30	120 90 70 60	200 160 120 80	310 260 200 140	480 390 310 230	up to 36” 37 - 48” 49 - 78” 79 - 96”
MP 60	40 40 40 40	80 60 40 40	150 120 80 70	270 210 150 90	440 350 270 180	650 540 440 330	up to 36” 37 - 48” 49 - 78” 79 - 96”
MP 70	50 50 50 50	100 75 50 50	210 155 100 70	400 300 210 110	620 510 400 280	870 750 620 500	up to 36” 37 - 48” 49 - 78” 79 - 96”
MP 155 MP 198 MP 240	60 60 60 60	150 100 60 60	330 240 150 100	600 460 330 195	900 750 600 450	1200 1030 900 750	up to 36” 37 - 48” 49 - 78” 79 - 96”

Table F₂Guide for Load Support at Troughing Idlers (Any Angle)

Multiple Ply Fabric Rated Ply Tension (AWT)	Material Weight Factors (MW) Plies				Belt Width
Multiple Ply Fabric Rated Ply Tension (AWT)	2	3	4	5	Belt Width
To 75	70 50 30 30	155 125 100 60	280 230 190 145		up to 36” 37 - 48” 49 - 78” 79 - 96”
To 105	85 60 40 40	200 160 120 80	370 300 240 170	550 470 400 320	up to 36” 37 - 48” 49 - 78” 79 - 96”
To 125	100 75 50 50	270 210 150 90	480 390 310 230	690 600 520 430	up to 36” 37 - 48” 49 - 78” 79 - 96”
To 150	150 105 60 60	400 300 210 110	650 540 440 330	850 760 670 580	up to 36” 37 - 48” 49 - 78” 79 - 96”

Abbreviations

AWT
Allowable Working Tension, operating tension (lbs/inch of width)

CW
Weight of conveyor system’s moving parts (lbs/lineal foot) Table A

D
Drive factor, used to calculate minimum slack tension (TS) at the drive pulley to give proper drive operation

F₁.035” (normal coefficient of friction value to move empty belt)

F₂.040” (normal coefficient of friction value to move loaded belt)

fpm
Feet per minute

H
Difference of elevation between terminal pulleys in feet

HP
Horsepower of drive

L
Conveyor length between terminal pulleys in feet

MW
MW = 33.3TPH/S or MW = Total Load (lbs)/L

S
Belt Speed in feet per minute

TE
Effective belt tension

TC
Tension required to overcome frictional resistance of moving unloaded belt

TH
Tension required to lift load

TL
Tension required to move loaded belt horizontally

TO
Operating tension (TE + TS)/W, sometimes expressed as AWT

TO-MAX
The maximum operating tension that a system can generate with given horsepower

TPH
Tons per hour

TS
Slack side tension

W
Belt Width

Load Support

Table F1 Guide for Load Support at Troughing Idlers (Any Angle)

Table F2 Guide for Load Support at Troughing Idlers (Any Angle)

Table F₁Guide for Load Support at Troughing Idlers (Any Angle)

Table F₂Guide for Load Support at Troughing Idlers (Any Angle)