SL-10

The isolator valve type SV/SL is a pilot operated check valve for subplate mounting or threaded connection. It is used for the leakage-free blocking of one actuator port, also in case of longer standstill times.

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The valve basically consists of a housing, a seat poppet, a compression spring, a control spool as well as of an optional pre-opening as ball seat valve. The seat valve can be flown through from A to B without external pilot pressure. In the opposite direction, the seat valve closes hydraulically tight. Condition: pA > pB + cracking pressure (compression spring).A sufficiently high pilot pressure at port X moves the control spool in the direction of the ball seat valve (version “A”) and pushes the seat poppet out of its seat.

This allows for a free flow in both directions (active keeping open).In order to ensure that the seat valve actively opens, the pressure ratios on both sides of the control spool are just as important as the area ratios at the control spool or seat poppet.

This results in the following available options for the types
▶SV (large annulus area A3 connected with pA) or
▶SL (small annulus area A4)
as well as for the versions with pre-opening “A” and without pre-opening “B”. Version “A” (with pre-opening)This valve is provided with an additional pre-opening. By pressurization at the X port, the control spool is moved to the right. As a result, the ball is pushed off the seat first and the seat poppet afterwards.