Could you explain exactly the meaning from API the standard 2.1.12? What is the diference the preferred operating region and rated capacity region? why there is more margin on the left (i.e. 70%) of bep than on the right (i.e. 120%)?
Thanks a lot
Its limited to the right of BEP because, other than the ovbious overspeed, hi power loads or limit, vibrations and eccentric load effects, the point where both the bearing and seal lives are severely affected.