KSB 4EYS, Installation & Operating Manual

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4 Description
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4EYS / 4EYT
1974.91/01-EN
4.5 Configuration and function
1 2 3
4 5 6
7
9 10
8
Fig. 1: Sectional drawing of a 4EYS
4 8 2 1
11 7 9
6
Fig. 2: Sectional drawing of a 4EYT
Design Mechanical seal for installation in pump sets and other rotating machinery in
accordance with the manufacturer's instructions.
KSB’s mechanical seal 4EYS / 4EYT is a cartridge seal that has been especially
developed for use in pumps of the Etabloc SYT and Etanorm SYT type series. Type
series 4EYS with nominal diameter D1 and installation dimension L1N is equivalent to
version N (normal design) and type U (unbalanced) in accordance with EN 12756.
Type series 4EYT with nominal diameter D1 is equivalent to version K (short design)
and type U (unbalanced) in accordance with EN 12756.
Function Primary ring 2 is the axially movable sealing ring which is pressed against mating ring
1 by springs 9. O-rings 5 and 6 are fitted for secondary sealing. On type series 4EYT,
thrust ring 7 engages with primary ring 2 and torque-transmitting element 8, forcing
them to rotate with the shaft without hindering the axial movability of primary ring
2. On type series 4EYS, bolts/screws 3 force primary ring 2 and torque-transmitting
element 8 to rotate together via discs 10 and thrust ring 7. Torque-transmitting
element 8 is connected to the shaft via grub screws 4. The axial movability of primary
ring 2 automatically compensates for wear and thermal expansion, maintaining
permanent contact between primary ring and mating ring. On type series 4EYT,
circlip 11, torque-transmitting element 8 and primary ring 2 hold together the
rotating mechanical seal assembly consisting of springs 9, thrust ring 7, O-ring 6,
torque-transmitting element 8, bolts/screws 4, primary ring 2 and circlip 11. On type
series 4EYS, the rotating mechanical seal assembly comprises torque-transmitting
element 8, primary ring 2, springs 9, thrust ring 7, bolts/screws 3, disc 10 and O-ring 5.