NSK high strength BMPC bearings are &#034pumping up reliability&#034 in arduous petrochemical processing plants

Citation

(2002), "NSK high strength BMPC bearings are &#034pumping up reliability&#034 in arduous petrochemical processing plants", Industrial Lubrication and Tribology, Vol. 54 No. 2. https://doi.org/10.1108/ilt.2002.01854bad.008

NSK high strength BMPC bearings are &#034pumping up reliability&#034 in arduous petrochemical processing plants

Keywords: NSK, Bearings, Petrochemical industry

Few working environments can compete with the potent mix of production demands and pressures routinely encountered in petrochemical processing plants. The problems of handling difficult-to-pump corrosive liquids, and the critical nature of applications themselves, are compounded by continuous working regimes, which are the result of intense pressures to deliver products on time (Plate 3).

Plate 3 NSK BMPC bearings meet the rigorous demands of centrifugal pumps for reliability and long service life

It is against this pressurised backdrop that centrifugal pumps continually test the endurance and integrity of rolling bearing designs. Test is indeed the operative word, for the centrifugal pump, in all its forms, is the most widely used unit for conveying fluids in the petrochemical industry. The key to its success is its simplicity: the kinetic energy of a rotating impeller is used to move, lift or transfer a fluid through a process system.

The nature of the applications for centrifugal pumps means that they are often located in difficult-to-service positions, which can be a problem as their reliability is paramount. So much so, in fact, that the API (American Petroleum Institute) has created standards for refinery service pumps that include details of bearing specifications. The API 610 standard (which because of its comprehensive and detailed nature has become a worldwide industry standard) calls for angular contact ball bearings having a40 degree contact angle arranged in a back-to-back configuration to give a minimum life expectancy of 25,000 hours(3 years) continuous running or 16,000 hours at maximum radial and axial loads and at rated speed; a demanding requirement. This bearing arrangement is also common in pumps used in pulp and paper, wastewater treatment, steel mills, irrigation, mining and many other demanding industries.

NSK is active in all the above market areas and is assisting their unique production requirements with a new series of bearings, designed specifically to meet the rigorous demands of centrifugal pumps – in particular the requirement to extend the periods between pump failures.

The new bearings, designated the BMPC Series, exceed the API 610 specification with the strongest machined brass cage in the industry, providing superior reliability in the harshest of applications. They also achieve longer service life, through smoother running, reduced levels of friction and lower temperature rise, the latter as a result of the better heat dissipation of the brass cage material.

The BMPC Series design is an amalgam of high strength materials technology, ABEC3 (P6) manufacturing tolerances and pump specific axial internal clearances. It delivers higher running accuracy, plus optimum levels of bearing stiffness, shaft positioning accuracy, load sharing and cooler running. In addition, the combination of super finished raceways, lowest inner-ring run-out and highest ball grade, all contribute to reduced levels of ball skidding and, hence, smoother operation.

The BMPC bearings are manufactured with 40 degree contact angles, ensuring the optimum angle to support both the thrust loading and rotational speeds of pumps. They also have universally ground faces allowing mounting versatility in either pairs or triplex sets, on a wide range of shaft sizes from 20mm OD to 150mm OD.

For less critical pumping applications, NSK manufacturers single row angular contact bearings with stamped steel or pressed brass cages, and universally ground faces. Also included in the NSK range are double row angular contact types, single row deep groove ball bearings and spherical, cylindrical and tapered roller bearings. What this means for the user is that the majority of pump bearing requirements can be satisfied quickly and effectively from one bearing range.

For more information contact: Michelle Reed, Marketing Communications Dept, NSK UK Ltd, Mere Way, Ruddington, Notts, NG11 6JZ, UK. Tel: +44 115 936 6600.