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MODEL

LOKB

Vent-to-open, spring biased closed, unbalanced poppet logic

element with pilot source from port 2

SERIES 4 / CAPACITY: 1100 L/min. / CAVITY: T-19AU

(X)CONTROL

X Not Adjustable

(D)CRACKING PRESSURE

D 50 psi (3,5 bar)

(N)SEAL MATERIAL

N Buna-N

V Viton

MATERIAL/COATING

Standard Material/Coating

/AP Stainless Steel, Passivated

CONFIGURATION

X Control Not Adjustable

D Cracking

Pressure

50 psi (3,5 bar)

N Seal Material Buna-N

(none) Material/Coating Standard

Material/Coating

NOTE: DATA MAY VARY BY CONFIGURATION. SEE CONFIGURATION SECTION.

These unbalanced, vent-to-open logic valves are 2-way switching elements that are spring-

biased closed and have port 2 as a pilot source. With port 3 blocked, the valve will remain in

the closed position in the 2 to 1 direction and will function as a check valve from 1 to 2. With

port 3 vented, the valve will open provided there is sufficient pressure to overcome the spring

force. 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

Cavity T-19AU

Series 4

Capacity 1100 L/min.

Maximum Operating Pressure 350 bar

Maximum Valve Leakage at 110 SUS (24 cSt) 0,7 cc/min.

Pilot Volume Displacement 7,7 cc

Area Ratio, A3 to A1 1.8:1

Area Ratio, A3 to A2 2.25:1

Control Orifice Diameter 0,9 mm

Valve Hex Size 41,3 mm

Valve Installation Torque 474 - 508 Nm

Seal kit - Cartridge Buna: 990019007

Seal kit - Cartridge Polyurethane: 990019002

Seal kit - Cartridge Viton: 990019006

Model Weight 1.16 kg.

snhy.com/

LOKB

Model Code Example: LOKBXDNCONFIGURATION OPTIONS

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TECHNICAL FEATURES

These valves will work in Sun's standard T-19A cavity at lower capacity. To realize the full stated capacity, the T-19AU cavity should

be used.

These valves open quickly when vented. Time to close is difficult to predict as it is dependent on the rate of flow and the pressure drop

created as it closes.

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.

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

LOKB8 Vent-to-open, spring biased closed, unbalanced poppet logic element with pilot source from port 2 and integral T-8A control

cavity