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    DN 80 - DN 450 (3” - 18”)
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    The optimal valve for high pressure slurry

High pressure knife gate valves SLH and SLX

Stafsjö’s knife gate valves SLH and SLX are designed for the most demanding high pressure applications with slurry and other abrasive media where operation reliability and low life cycle cost are emphasized. The SLH is designed for pressure up 20 bar/290 psi while the SLX is designed for 50 bar/720 psi.

When these valves are in opened position, the seats form a tight extension of the pipe line and no metal parts are in contact with the media. When the valve closes the seats are displaced axially forming a seal with the gate until it forms a complete closure – 100% tight in any pressure direction.

The SLH and SLX have fully lugged coated valve bodies in nodular iron with integrated purge ports to utilize if the covers are fully assembled on the valves. The unique seats are available in low friction special EPDM or natural rubber. These seal against a gate in high strength stainless steel specially machined, grinded and coated to reduce the friction when the valve is operated.

The SLH and SLX valve is available from DN 80 up to DN 450 (3" to 18”) and larger sizes on request. Further information is available in the product data sheet.

Other slurry valves are the SLV and the fully flanged SLF.


A precise gate guidance extend the service life

A solid top works (1), a robust gland box system (2), internal guiding supports (3) guarantee a precise gate guidance, which is crucial during cycling to minimize the wear on the seats.

Built in steel reinforcements improve the performance

The front reinforcement rings (4) ensure the seats shape, position and strength remain during operation while the flange sealing reinforcements (5) secure a tight and exact position of the seats towards the connecting flanges. 

Integrated expansion areas give low operating force and minimize the stress on the seats

The seat entrance area (6) is designed to give a smooth gate entry and the expansion area (7) allows the seat to be axially flexible requiring minimal operating force. 

Contact us if you have any questions