DIRECTIONAL VALVES
DESCRIPTION
A screw-in, cartridge-style, pilot-operated, spool-type, normally closed, hydraulic
directional valve for two-way circuits requiring remote pilot actuation.
OPERATION
In neutral (unpiloted), the PD12-34 blocks fl ow from ➂ to ➁ bidirectionally.
V is a spring chamber vent-to-atmosphere, which is internally O-ring sealed from the
cartridge fl ow paths.
On remote pilot signal at
➀, the valve shifts to open ➁ to ➂ bidirectionally.
Because of the vented spring chamber, the cartridge may be fully pressurized at any
port without affecting required pilot pressure.
FEATURES
• Hardened spool and cage for long life.
• Cost-effective cavity.
RATINGS
Operating Pressure: 240 bar (3500 psi)
Proof Pressure: 420 bar (6090 psi)
Flow: See Performance Chart
Internal Leakage: 82 cc/minute (5 cu. in./minute) max. at 207 bar (3000 psi)
Pilot Pressure Required for 7.6 bar (110 psi) Spring:
to Cross-Over: 7.6 bar (110 psi)
to Full Shift: 9.1 bar (132 psi)
Oil Volume Required to Full Shift: 1.32 cc (0.08 cu. in.)
Temperature: -40 to 120°C with standard Buna seals
Filtration: See page 9.010.1
Fluids: Mineral-based or synthetics with lubricating properties at viscosities of
7.4 to 420 cSt (50 to 2000 sus); See Temperature and Oil Viscosity, page 9.060.1
Installation: No restrictions; See page 9.020.1
Cavity: VC12-3; See page 9.112.1
Cavity Tool: CT12-3XX; See page 8.600.1
Seal Kit: SK12-3X-MM; See page 8.650.1
Cap Vent Seal: 6003121
SYMBOLS
USASI: ISO:
4.329.1
PERFORMANCE (Cartridge Only)
12.4/180
9.3/135
6.2/90
3.1/45
22.7
6
45.4
12
90.8
24
FLOW lpm/gpm
PRESSURE DROP bar/psi
113.6
30
68.1
18
to
32 cSt/150 ssu oil at 40°C
➂➁
PD12-34 Piloted 2-Way Spool, Normally Closed,
Note: This valve is designed with a dynamic oil-to-atmosphere seal in the vent
section. Ambient conditions will cause this vent seal to degrade which will reduce the
valve’s cycle life. If this could cause a problem, we suggest that a non-vented model
be selected, or special seal be used. Consult factory for assistance.
HYDRAFORCE
.com
®
Blue rectangles are links to other catalog pages.
DIMENSIONS
MATERIALS
Cartridge: Weight: 0.23 kg. (0.50 lbs.)
Steel with hardened work surfaces;
Zinc-plated exposed surfaces.
Buna N O-rings and polyester
elastomer back-ups standard.
Standard Ported Body: Weight:
1.13 kg. (2.50 lbs.) Anodized high-
strength 6061 T6 aluminum alloy,
rated to 207 bar (3000 psi); Ductile
iron bodies available; dimensions
may differ. See page 8.012.1.
TO ORDER
Bias Spring
110 7.6 bar (110 psi)
170 11.7 bar (170 psi)
PD12-34 - __ __ __ - __ -__ __ __
PD12-34
4.329.2
Porting
Cartridge Only 0
SAE 8 8T
SAE 10 10T
SAE 12 12T
1/2 in. BSP* 4B
3/4 in. BSP* 6B
*BSP Body
U.K. Mfr. Only
External Vent
Seals
N Buna N (Std.)
NS Buna N with Sealed Spool
V Fluorocarbon
VS Fuorocarbon with Sealed Spool
®
HYDRAFORCE
HYDRAFORCE
.com
®
Blue rectangles are links to other catalog pages.
