Belt EP designation & width

Carcass Rating (n in EP n/p) N/mm

Minimum breaking strength of the whole carcass per mm of belt width, from the designation.

Plies (p in EP n/p) plies

Belt Width mm

Drive Effective tension & pulley grip

Effective Tension at the Drive (Te) kN

From the conveyor resistance calculation. Use the starting value if starting raises it above running.

Wrap Angle on the Drive Pulley deg

About 180° on a plain head drive; more with a snub pulley; add the angles of a dual drive.

Belt-to-Pulley Friction Coefficient μ

Depends on lagging and on whether the pulley runs wet. Take the value your design method gives.

Design Safety Factor x

Breaking strength divided by the allowable working tension, as your design rule sets it.

Belt Rating Used

— %

Tight-side tension per mm against the allowable working tension; above 100% the belt is under-rated

Tensions & Rating

Tight-Side Tension T1: — kN
Slack-Side Tension T2 (minimum to avoid slip): — kN
Grip Factor e^(μθ): —
Working Tension per mm of Width: — N/mm
Allowable Working Tension: — N/mm
Safety Factor the Belt Runs At: — x
Smallest Rating at Your Factor: — N/mm
Breaking Strength per Ply: — N/mm

In an EP n/p designation, n is the minimum breaking strength of the whole carcass in N per mm of belt width and p is the number of plies, so EP 630/4 is 630 N/mm in four plies of about 157.5 N/mm each. The tensions follow the Euler-Eytelwein relation for a belt on a driving pulley: T1 = Te x e^(μθ) / (e^(μθ) - 1) and T2 = T1 - Te, with θ the wrap angle in radians; T2 is the least slack-side tension that passes Te without slip, and the take-up must supply at least that. The safety factor is your input: published guidance for fabric belts runs from about 8 to 10 and rises with poor splices and hard starts, and DIN 22101 sets the full method. This check leaves out sag tension between idlers, transition and curve stresses, acceleration of the load at start and splice efficiency, any of which can set the rating instead. **A first check of the carcass rating, not a conveyor design.**

Fabric Conveyor Belt Tension & EP Rating Check — free, with the formula and a worked example, at Textile School.