New Holland T8010 Manual page 744

Some cylinders have cushions built into them. The cushion
slows down the movement of the piston as it nears the end of
its stroke. Cylinder cushions are shown as a smaller
rectangle on the piston. If the cushion has an adjustable
orifice, a slanted arrow is drawn at 45 degrees across the
symbol.
Section 35 - Hydraulic Systems, 3PT - Chapter 1
35-1-7
Pressure Control Symbols
The basic symbol is a square (which is called an envelope)
with external port connections and an arrow inside to show
the oil passage and direction of flow. Usually this type of
valve operates by balancing the oil pressure against a spring,
so a spring is shown on one side of the symbol and a pilot
pressure line on the other side.
Normally Closed
ARROW OFFSET
FROM PORTS
INLET
PILOT
LINE
SPRING
OUTLET
NORMALLY CLOSED
712L8B
A normally closed valve, such as a relief or sequence valve, is
shown with the arrow offset from the ports and toward the
pilot pressure line side of the square. The spring holds the
valve closed until the pilot line oil pressure is greater than the
spring pressure. Mentally visualize a build up of pressure in
the pilot line and the square moving over, compressing the
spring. The oil can now flow through the valve.
Normally Open
INLET
PILOT
LINE
SPRING
OUTLET
NORMALLY OPEN
712L8D
A normally open valve is shown with the arrow connecting the
two ports. It closes when pressure overcomes spring force.
Mentally visualize a build up of pressure in the pilot line and
the square moving over, compressing the spring. The oil flow
through the valve is now blocked.
ARROW ALIGNED
WITH PORTS
MENTALLY VISUALIZE SQUARE
MOVING TOWARD SPRING
712L8C
MENTALLY VISUALIZE SQUARE
MOVING TOWARD SPRING
712L8E