Spool schematics, Safety precautions – BRAND Hydraulics SDCF DIRECTIONAL CONTROL VALVES User Manual
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T
P
A
B
Tandem Center (T) - Powers cylinder or motor in
both directions (metering capability is very limited).
Pump unloads to tank when spool is in neutral.
Cylinder or motor blocked when spool in neutral.
Open Center (O) - All of the ports are connected to
tank when the spool is in neutral. Allows cylinder to
move or motor to rotate when spool is in neutral.
Fine Metering Spool (M) - The pressure drop in
neutral is higher then the (OM) and (TM) spools.
Requires external locking valves to hold cylinder,
because ports A and B are open (orificed) in the
neutral position. Extremely fine metering control.
Open Metering Spool (OM) - The neutral pressure
drop is much lower then the (M) spool. Extremely
fine metering control. Ports A and B are open
(orificed) in the neutral position.
B
A
P
T
B
A
P
T
B
A
P
T
Tandem Metering Spool (TM) - Similiar to (T) spool
except much finer metering control. The pressure
drop in neutral is lower then the (M) spool. Cylinder
or motor blocked in neutral and pump unloads to
tank.
P
T
A
B
SPOOL SCHEMATICS:
SAFETY PRECAUTIONS:
It is the purchaser’s responsibility to determine the suitability of any Brand Hydraulics Co. product for an intended
application, and to ensure that it is installed in accordance with all federal, state, local, private safety and health
regulations, codes and standards. Due to the unlimited variety of machines, vehicles and equipment on which our
products can be used, it is impossible for Brand Hydraulics Co. to offer expert advice on the suitability of a product
for a specific application. It is our customer’s responsibility to undertake the appropriate precautions, testing and
evaluation to prevent injury to the end-user.
Overpressure may cause sudden and unexpected failure of a component in the hydraulic system, resulting in serious
personal injury or death. Always use a gauge when adjusting a relief valve.