Centrifugal compressors shaft seal

Used by permission Koch, D. T. Centrifugal Compressor Shaft Seals, ref. 35, Jan. 3, 1958. Cooper-Cameron Corp. Reprinted with permission Nelson, W. E. Hydrocarbon Processing, V. 5, No. 2, p. 91 [97], 1977. Gulf Publishing Co., Houston, Texas. All rights reserved. 

Figure 12-51 A. Multistage centrifugal compressors shaft seal arrangements. (Used by permission A C Compressor Corporation.)...

The centrifugal compressor is composed of a casing containing a rotating element, rotor, which is supported by a set of bearings. For most multistage compressors, shaft end seals are located in-board of the bearings. 

Figure 12-70B. Typical mechanical losses for seals on shafts of centrifugal compressors. (Used by permission Bui. P-26. Elliotl Co.)...

The sealing systems for the shaft are quite similar to those for the centrifugal however, internal shaft seals are not necessary between stages. The materials of construction are similar to those for the centrifugal compressor. 

The shaft-seal development for high-pressure centrifugal pumps is quite similar to that explained for compressors. The traditional mechanical seals lubricated by liquids are now being partly replaced, for obvious reasons, by gas-lubricated ones. 

Figure 76. Liquid film shaft seal with nlindrkwl hushing lor a high-pressure centrifugal compressor a) Shaft b) Bearing c) Pressure side d) Ambient side e) Floating seal rings f) Sea) oil surge vessel g) Sea) oil h) Lube oil i) Drain to gas-oil separaior k) Drain lo lube oil tank l) Elevation for seal oil head...

Shaft sealing system for centrifugal compressor can be dry gas seals— but not for inflammable gases. Water-cooled seals should be discussed with vendor... 

Mechanical seals have been increasingly used to seal rotating shafts for more than seven decades. Currently, they are the most common types of seals found on items such as centrifugal pumps and compressors used in the oil and gas industry. Over the years, the failure of mechanical seals has become an important issue. For example, a study conducted in a petroleum company reported that 60% of plant breakdowns, directly or indirectly, were due to mechanical seal failures [3]. 

---