Created on 12/14/2016

 2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2

MODEL

LKJB

Block port 3 to open, spring biased closed, unbalanced poppet logic element

with pilot source from port 2

SERIES 4 / CAPACITY: 480 L/min. / CAVITY: T-19A

These unbalanced poppet, 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 open provided there is sufficient pressure at port 2. With port 3

vented, the valve will close. The force generated at port 3 must be greater than the sum of the forces acting at port

1 and port 2 plus the spring force for the valve to open. 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-19A

Series 4

Capacity 480 L/min.

Maximum Operating Pressure 350 bar

Pilot Volume Displacement 4,9 cc

Area Ratio, A3 to A1 1.8:1

Area Ratio, A3 to A2 2.25:1

Control Orifice Diameter 0,53 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 1.20 kg.

(X)CONTROL

X Not Adjustable

(D)MINIMUM PILOT PRESSURE

D 50 psi (3,5 bar)

(N)SEAL MATERIAL

N Buna-N

V Viton

snhy.com/

LKJB

TECHNICAL FEATURES

Model Code Example: LKJBXDNCONFIGURATION OPTIONS

Created on 12/14/2016

 2016 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2

These valves have positive seals between port 2 and the pilot area.

When port 3 is blocked these valves start to open at the pressure one would expect. However, because the valves have to generate their own pilot pressure, the

pressure drop across the valve increases at a high rate as shown in the performance curve.

These valves do exactly what they are supposed to do. They do not do what most customers would expect them to do. This is why we do not promote them as

viable products.

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).

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