Dear Shri Rajesh Kale,

Present day textile fabric common belts are specified as below as an example :

1200 mm wide, EP 800/4, top cover 6 mm, bottom cover 3mm, grade M. This implies belt width is 1200mm, it has 4 ply of which total breaking strength is 800 N/mm, it has 6 mm top cover and 3 mm bottom cover. As would be evident it is made of 4 ply each having tensile breaking strength of 200 N/mm.

Similarly, for steel cord belts

1200 mm wide, St 800, top cover 6 mm, bottom cover 3mm, grade M. This implies belt width is 1200mm, it has breaking strength of 800 N/mm, it has 6 mm top cover and 3 mm bottom cover.

For more constructional details of the belt, refer published catalogues / leaflets of belt manufacturers.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Here are a few mfgrs.

Goodyear tire & Rubber Co. has diagram info. and can provide more:

http://www.goodyearindustrialproduct...eel.html#fspec

ContiTech: you have to ask for brochures - they do have the composition you are looking for.

http://www.contitech.de/ct/contitech...baendere.html

Lawrence Nordell

www.conveyor-dynamics.com ■

Dear Shri Rajesh Kale,

Generally, the wire diameter, pitch etc are as per the standard design and construction of the belt manufacturer. Normally, buyer should not try to specify these parameters unless he has expertise on the subject matter.

Most of the belt manufacturer will be manufacturing their belts as per reputed and recognized international standards; otherwise they will find it very difficult to sell. If you want to know these parameters, please refer DIN 22131 Part 1, 2, 3 etc., which will provide you all the information about the wire diameter, their pitch, adhesive cover portion, top cover portion etc. and also how to join such belts by vulcanising.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr.Kale,

Like NN belt, we also specify steel cord belt like as given below:

ST-2000

Belt width,mm....1200

Top cover,mm....6

Bottom cover,mm....3

Open end length,m....1314

Edge construction..... Cut edge

Cover grade.....M24

With this you will get your belt. You need not have to be spesify the diameter of steel cord,no. of strand etc...

Regards.

A.Banerjee ■

Hello Mr Kale.

My learned colleagues have filled you in on most of what is required to define a steedcord belt. Here are some other points to remember:

- Unlike fabric belt, you need alot of rubber to contain (and splice) the steel cords in the belt. For this reason you need a belt which is often almost symetrical with equal covers e.g. 5 x 5mm or 6 x 6mm. You can add more top cover for wear if you want to.

- You can have a few large diameter cords or a lot of smaller ones. The larger the cords the larger the required pulley diameter, but the better the impact resistance.

- Nice to have the same number of cords as the belt you will splice the new roll into

- Safety factor of Steelcord belts is normally 6.7:1 where fabric is 10:1 due to splice inefficiency with fabric ones.

Regards

LSL Tekpro ■

Halo Graham,

Mr. Kale wants to know how to specify a steel cord belting. He does not want to specify internal construction of the belting.In practise it is not required at all.Why you have written that Kale have to remember!!!

In steel cord belting, the factor of safety at starting/braking will be 6:1. Your last point is not clear to me.

Regards.

A.Banerjee ■

Dear Mr Banerjee..

I find it difficult to be polite to you with the tone you set, but never mind that.

If you do not find my contributions of use then please ignore them.

Regarding the safety factor of steelcord belt, we will be presenting our paper on the "Golden Rules" at Beltcon 13 which covers the safety factors in steelcord belts in great detail.

To simply say the safety factor on starting/braking is 6:1 is complete simplistic rubbish, and the actual truth is that in practice it must not fall below 3.8:1 taking everything into consideration.

The normal running safety factor is generally taken as 6.7:1 for steelcord.

For fabric it is normally 10:1 When you splice a 3 ply belt for example, you effectively get two pairs of plies overlapping, therefore reducing the strength to 2/3.

2/3 x 10 = 6.7

The fabric belt therefore has a safety factor of 10 which drops typically (3 plies) to 6.7.

LSL Tekpro ■

Dear Mr.Graham,

Normally steel cord belting is used for long distance transportation where NN belting does not meet the tension requirement&so on...The steel cord belting is costly & replacement of such long belt is a big problem.So plant operational people do not want to invite any hazard due to failure of belting. I did many down hill conveyor along with others in BALADIALA MINES in INDIA.The client wants specifically SF=6 at starting/braking.In catalouge you will find SF=7 at running & at starting it will be reduced to 60 to70- percent.Bridge stone refer 3-4 SF at joint.No body knows when there will be over loading & jamming of take-up, causing increase of tension at any stage.SF also depands on type of client .

I do not know that which tone had made you biassed against me.Kindly excuse me if by mistake I did so.

Regards.

A.Banerjee ■