Sequence Valves The Cross SQV series valve is a 2-position, 3 port valve designed to alternately operate a pair of agricultural guide marker cylinders. May be used with single acting or double acting marker cylinders. Request a Quote find a distributor find a distributor Request a Quote × The SQV hydraulic valve series offers 2 position, 3 port and is rated 2500 psi, 2 GPM. Hydraulic Sequence Valve Model SQV