The disclosed spool valve is used especially in conveying systems comprising conveying pipes (6, 7) and includes a spool (1) which allows the conveying cross-section of the conveying pipe (6, 7) to be closed. The spool (1) has at least one through-hole (33). The conveying pipe (6, 7) is sealed from the spool (1) by at least one sealing ring (27, 28). Said sealing ring (27, 28) surrounds the conveying line (6, 7) and includes a washer-shaped sealing portion. Said sealing portion lies flat on the spool and seals under the effect of the difference between the pressure in the conveying line (6, 7) and the ambient pressure.