Created on 02/12/2016
c
2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
LOHC
Pilot-to-close, spring biased closed, unbalanced poppet logic element
SERIES 3 / CAPACITY: 380 L/min. / CAVITY: T-17A
These unbalanced, pilot-to-close logic valves are 2-way switching elements that are spring biased closed. Pressure
at either work port 1 or 2 will oppose the spring and tend to open the valve while pressure at port 3 will tend to
close it. The force generated at port 3, plus the spring force, must be greater than the sum of the forces acting at
port 1 and port 2 for the valve to remain closed. NOTE: The pilot area (port 3) is 1.8 times the area at port 1 and
2.25 times the area at port 2.
TECHNICAL DATA
Maximum Operating Pressure 350 bar
Maximum Valve Leakage at 110 SUS (24 cSt) 0,7 cc/min.
Pilot Volume Displacement 4,1 cc
Pilot Passage into Valve 1,50 mm
Area Ratio, A3 to A1 1.8:1
Area Ratio, A3 to A2 2.25:1
Seal kit - Cartridge Buna: 990-017-007
Seal kit - Cartridge EPDM: 990-017-014
Seal kit - Cartridge Polyurethane: 990-017-002
Seal kit - Cartridge Viton: 990-017-006
(X)CONTROL
X Not Adjustable
(D)CRACKING PRESSURE
D 50 psi (3,5 bar)
(N)SEAL MATERIAL
N Buna-N
E EPDM
V Viton
MATERIAL/COATING
Standard Material/Coating
/AP Stainless Steel, Passivated
snhy.com/LOHC
TECHNICAL FEATURES
These valves have positive seals between port 2 and the pilot area.
Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage
the seals.
Because these valves are unbalanced, operation is pressure dependent. Opening and closing of the poppet are functions of the force balances on three areas: Port
1 = 100%, Port 2 = 80%, and the Pilot Area = 180%.
These valves are pressure responsive at all ports, therefore it is essential to consider all aspects of system operation through a complete cycle. Pressure changes
at any one port may cause a valve to switch from a closed to an open position, or vice versa. All possible pressure changes in the complete circuit must be
considered to assure a safe, functional system design.
Model Code Example: LOHCXDNCONFIGURATION OPTIONS
Created on 02/12/2016
c
2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
All ports will accept 5000 psi (350 bar).
Corrosion resistant cartridge valves are intended for use in corrosive environments and are identified by the model code suffix /AP for external stainless steel
components, or /LH for external zinc-nickel plated components. See the CONFIGURATION section for all options. For further details, please see the Materials of
Construction page located under TECH RESOURCES.
Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge
machining variations.
PERFORMANCE CURVES
RELATED MODELS
LOHCK Pilot-to-close, spring biased closed, unbalanced poppet logic element
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LOHCZ Pilot-to-close, spring biased closed, unbalanced poppet logic element with position switch
