Broad-scale testing of static seals on boiler feed pumps
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 119 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 0262-1762
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✦ Synopsis
FINANCIAL B Broad-scale t e s t i n g of static seals on boiler feed p u m p s KSB Aktiengesellschaft in Frankenthal, Germany has just c o m p l e t e d a three-year test programme for such static sealing systems as those used in boiler feed pumps. The tests were conducted in collaboration with the Mannheim and Kaiserslautern technical colleges and several notable seal manufacturers.
The failure of a single static seal can cause an entire plant to come to a standstill. The quest for increasingly long p u m p m a i n t e n a n c e intervals and altered modes of boiler operation is calling for evermore efficient seals. The increasing aggressiveness of boiler feed water in recent years due to the presence of such additives as ammonia, coupled with the ban on asbestos in seals,has prompted p u m p manufacturers and a n u m b e r of p o w e r plant operators to investigate the practicability of some n e w sealing materials and concepts.
With this in mind, KSB designed a test stand for shaking d o w n seals with diameters up to 600 m m under near-real conditions at static pressures up to 400 bar and temperatures up to 200 °C. The setup even allowed t h e r m a l d e f o r m a t i o n of the c o m p o n e n t s by as much as 1 mm. Incorporation of a variablesize seal housing made it possible to simulate deformation of the seal body in a feed water p u m p caused by transient operating conditions, e.g. during starting and stopping.
The test stand's programmability and c o m p u t e r i z e d measured-data logging c a p a c i t y enabled representation of practically any set of operating conditions that a feed water p u m p could ever encounter. Vital information was gleaned from tests geared to sounding out the serviceability limits of seals w h i c h are either subject to overload c o n d i t i o n s or have not been p r o p e r l y installed. The analysis of this data h e l p e d define optimal-selection param-cters for individual ranges of application.
The resultant k n o w -h o w will make it possible to double the maintenance intervals of some p u m p series from three years to six.