sleeve in mechanical seal?

[marengineer]

some mech seal have sleeve some dont.what s the reason for that?yes it can be about liquid types.but i saw a pump which discharge water at 25C also use sleeve for mech seal.

sorry for my poor english

thanks in advance

 

[bk19702]

Most drastic classification difference is that pump seals with their own sleeve are usually cartridge designs, and they are most likely built within their own gland plate as well. Cartridge seals eliminate many installation errors as they are preset at working height and only require locking down of collar set screws and tightening of gland stud nuts prior to service. Cartridge seals are required per API standard 682. A component seal will not have it's own sleeve; it will be used to mount to an old packing sleeve usually with the stationary face pressed into a gland typically provided by the pump OEM. The component requires measurement of the installation reference (found on the seal drawing), and marking this location on the pump sleeve for location of the seal head mount. Open to more errors in this manner, but still used in some less critical services. When the transition from packing to mechanical seals began however, this was the norm before cartridges were developed. This is a very brief answer based on limited information, but hopefully it clears things up for you somewhat.

 

[flexibox]

Component unbalanced seals are normally fitted on a parallel sleeve diameter. These seals have a Pressure limit of approx 10bar depending on shaft diameter. Component Balanced seals fit on a stepped shaft sleeve in order to establish a Balance diameter. This diameter is critical to maintain a standard balance ratio. These seals are not redily available anymore because as BK19702 mentions cartridge seals have become standard supply. Your pump is most likely fitted with a simple unbalanced seal mounted on the Pump shaft sleeve.

trust this helps

 

[marengineer]

thanks a lot for your informations