As PM to whom you'll award the contract. 3 vendor A,B,C all qualifying while Procurement Director recommending Vendor A & Project manager recommend B?

The most important thing is which supplier (A or B) can deliver the right material within the project's budget and specified timeframe. If supplier B qualifies to do the job and the material in question is project related, then the contract would be awarded to supplier B. 

I'll award the contract to vendor B, In case it is a project related.

In case it is a project related than i will award it to vendor B

I will look at many factors which are time, quality and price, if all matches then I will look at previous experience, accessability, experience, availability in the market, I will call other companies to ask about these suppliers and then i will be able to convince my managers with whom we should proceed.