This thread is about 14 years old. I am attending it just for general information. Presently this may not have relevance to your problem.

You have chosen pipe conveyor which can carry iron ore at the rate of upto 500 mtph. Your query is whether the pipe conveyor will have any problem if you use it for 150 mtph. As a rule, pipe conveyor cannot have problem even when running at empty condition, because continuous feeding round the clock is not possible most of the times and some times there may be no material to feed. So conveyor or pipe conveyor cannot not have problem when running at empty or partial or full load condition.

Only in some types of rotary crushers, frequent empty running is not advisable because it will make noise and reduce the life of crusher.

Ishwar G. Mulani
Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is 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