Hydraulic motor spool valve question

[Wally01]

Am I correct in believing that if you were to use a a motor spool valve on a double acting hydraulic cylinder, it would work while pressure was being applied, but once the valve was in the 'neutral' position, the cylinder would not hold, but float?

Thanks Wally

 

[MadReferee]

Yes, that is essentially correct. Both work ports are connected to the tank circuit (or the outlet when the valve does not have power beyond) when the spool is in neutral.

The following is from the Prince SV manual:

The Series SV Motor Spool provides control of reversible hydraulic motors. Both work ports are connected to the open center core in the neutral position, It should be noted that in the neutral position, the work ports will be equally pressurized to the same pressure that is required of any downstream valve sections and that a work port relief in the section will also limit the pressure of any other sections in the valve. The series motor spool should not be used to control a hydraulic cylinder as unwanted cylinder drift may occur in the neutral position.