Hello,

One is concerned with the issue of belt quality at 2 stages. The first stage is during quoting that is which quotation to consider for pricing. The second stage is after receiving the equipment order from buyer when you are looking for actual placement of order for getting the belt.

Stage - 1: In this case you can decide on following consideration / information from supplier:

1) Nature of the company whether private limited or public limited

2) Annual turn over for the manufactured belt

3) Reputation of the company as a supplier of the belt

4) Ask to the supplier for prominent name of the belt buyers (like electricity board, national power corporations, public sector mines, steel plants, fertilisers plants, top ranking manufacturers of belt conveyor in your country, and so on)

5) Suppliers product range

6) Whether above is in line with your requirement

7) Comparative price. The price should be neither very low nor very high as compared to the leading manufacturer of the belt

8) Guarantee for service life.

Stage – 2: In this case your quality and inspection department is involved in the decision for selection of the supplier if the supplier is new to your organisation. Then inspection department knowledgeable engineer visits the belt manufacturer’s plant to see the manufacturing facility, quality control facility (testing concerned materials and product i.e. belt guaranteed technical features). Reputed standards define various tests, etc. After visit the inspection engineer provides formal report to the company about his observation and technical reliability of the belt.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Dear Jay,

The Ocean Rubber quote is rubbish belt. The way you need to evaluate these tenders is as follows;

> Tensile strength, the OCR is low the other much better and frankly the higher the better

> SG: you need to know the SG of EPDM Rubber (it is a heat resistant compound). Top of my head I do not remember but I believe it is around the 1.5 mark and one quotation shows an SG that verifies this is what they are supplying the other suggests they are cheating by either supplying a non EPDM belt (most likely a clay filled SBR) or an EPDM that has lots of cheap fillers

> Descriptions like abrasion loss is good is rubbish. You need to know the test used and and the material lost under the standard

> You need to specify a temperature range you are working to and get a performance guarantee and references you can rely on.

> In both instances the elongation is low but EPDM is a stiff compound. Grade A to Aust Standards specifies a minimum of 450% but it may well be this is not possible with EPDM

Overall you need to have a Standard against which you can evaluate and the Australian and British Standards are quite good. You need references and guarantees and if you have doubts after all this tell them you you want a bank guarantee backing the expectation they have promised that can be accessed on a pro-rata basis for the % the belt fails to deliver on the guarantee given. The other thing with EPDM belts you need to find out about is how they will join the belts as hot vulcanising EPDM is very difficult

Hope this helps

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.com ■

Ocean rubber have possibly described a 5year old belting offer whereas the Sharjah firm is describing rubber insertion. You have no means of directly comparing these datsheets.

Since the belt is intended for repair it seems you have gone to belt stockholders rather than manufacturers: which is quite acceptable. Furthermore the repair belt must closely match the originally supplied parent belting, or else. Show the datsheet for the original belt to the stockholders and see what is on offer.

At first glance 12mm is a bit over the top for skirt sealing duty. You should never use belting for skirt sealing. ■