Walvoil SD5/6-P(KG3-160)/18L/18L/18L/18L/18L/28L/AET is a 6-section sectional hydraulic valve with a KG3-160 mechanical joystick control,rated for 160 L/min inlet flow.As a hydraulic spool valve designed for mobile machinery,it delivers independently configurable flow rates across six working sections—five at 18 L/min and one at 28 L/min—enabling precise control of multiple hydraulic actuators from a single compact manifold.Suitable for articulated loaders,agricultural tractors,and construction equipment.

　　What Is a Sectional Hydraulic Valve?

　　A sectional hydraulic valve is a modular directional control valve assembled from individual spool sections bolted together on a common inlet and outlet manifold.Each section controls one hydraulic actuator—a cylinder or motor—with independent flow and spool configuration.Monoblock valves,in contrast,cast all spools into a single body,limiting reconfiguration after manufacture.

　　Sectional valves are classified by their stacking principle:open-center(constant flow,low standby pressure),closed-center(load sensing,variable pump compatibility),or tandem-center.The Walvoil SD5 series uses an open-center stackable architecture,meaning sections can be added,removed,or reordered in the field by the OEM or service technician.

　　Key Specifications

　　Number of Sections:6(five 18 L/min sections,one 28 L/min section)

　　Nominal Inlet Flow Rating:160 L/min

　　Section 1–5 Flow Rating:18 L/min per section

　　Section 6 Flow Rating:28 L/min

　　Maximum Operating Pressure,Parallel Circuit(P to A/B):350 bar

　　Maximum Operating Pressure,Series Circuit:280 bar

　　Maximum Back Pressure on Tank Port:5 bar

　　Spool Type Options:Double-acting(A and B ports),spring-centered to neutral

　　Control Type:KG3-160 mechanical joystick with cable actuation

　　Actuation Force at Control Lever:12–18 N(with KG3-160 control)

　　Hydraulic Oil Viscosity Range:15–100 cSt(ISO VG 32–68 recommended)

　　Maximum Oil Temperature:100°C continuous,120°C intermittent

　　Filtration Requirement:ISO 4406 21/19/16 minimum(recommended 18/16/13)

　　Mounting Orientation:Any orientation;vertical joystick mount recommended for cable routing

　　Section Material:High-tensile cast iron

　　Seal Material:NBR(FKM available for high-temperature applications)

　　Port Connections:BSPP(G-thread)or SAE flange per customer configuration

　　Certifications:Designed to ISO 10762 mounting interface;CE compliance per Machinery Directive 2006/42/EC

　　Technical Highlights

　　Independently configurable flow ratings per section optimize pump sizing.Five sections deliver 18 L/min and one delivers 28 L/min.This mixed-flow arrangement allows the machine designer to match each actuator’s speed requirement without adding external flow controls.A common sizing question is whether sections can be swapped—the spool assemblies are interchangeable,and replacement sections with different flow ratings can be ordered individually.

　　Mechanical joystick control eliminates electro-hydraulic complexity.The KG3-160 is a two-axis mechanical remote control that actuates spools via push-pull flexible cables.This provides direct,proportional feel without solenoids,wiring harnesses,or electronic controllers,and operates reliably in wet environments and after vehicle battery failure.

　　Open-center design enables continuous flow circulation.In neutral spool position,pump flow passes through the valve and returns to tank at low pressure drop,maintaining constant pump circulation without deadheading.For machines using fixed-displacement gear pumps,this reduces heat buildup during idle periods.

　　Load check valves prevent reverse flow drift.Each working section includes an integrated load check valve that holds the load when spools transition between positions.This prevents cylinder creep and load dropping on inclined surfaces,critical for loader boom and fork tilt functions in material handling.

　　Cast iron body with high tensile strength withstands system fatigue.The SD5 series uses high-tensile cast iron with 350 bar rated pressure,providing robust fatigue resistance under the pressure pulsations common in mobile hydraulic circuits.

　　Applications

　　Articulated wheel loaders and compact loaders:Controls boom lift,bucket tilt,and auxiliary attachments such as grapples or sweepers.The 28 L/min section typically drives high-speed auxiliary functions while five 18 L/min sections handle simultaneous lift and tilt with flow-sharing characteristics.

　　Agricultural tractors and front loaders:Manages front loader functions(lift arm,bucket,grapple)plus rear hydraulic remotes from a single joystick station.Open-center architecture matches the standard gear pump configuration on utility tractors.

　　Backhoe loaders and excavators:Provides individual spool control for boom,dipper,bucket,swing,stabilizer,and auxiliary breaker circuits.The mechanical joystick delivers the tactile feedback operators require for precision grading and trenching.

　　Telehandlers and rough-terrain forklifts:Directs flow to lift,tilt,extend,and frame-leveling cylinders.Load check valves on each section hold suspended loads during transport,meeting the critical stability requirements of material handling machines.

　　Municipal vehicles and street sweepers:Controls hydraulic brooms,conveyor belts,water pumps,and side-arm mowers.Cable-operated joystick isolation allows cabin placement of the valve for noise reduction while maintaining smooth control feel.

　　Forestry and logging equipment:Manages grapple saws,delimbers,and log loaders.The mechanical control remains functional in sub-zero cold starts where electro-hydraulic solenoid coils may fail to energize.

　　Selection Guidance

　　Suitable applications:

　　Fixed-displacement gear pump systems with open-center hydraulic circuits delivering up to 160 L/min total flow

　　Mobile machines requiring mechanical joystick control without electronic infrastructure—the KG3-160 provides two-axis proportional spool actuation via cable linkage

　　Multi-function vehicles where switching between attachments(buckets,grapples,mowers)requires different flow allocations per attachment;individual spool sections can be replaced or reconfigured as machine duties change

　　OEM designs requiring flexible valve section sequencing during prototyping;sectional construction allows reordering of functions without replacing the entire valve stack

　　Not recommended for:

　　High-flow circuits exceeding 160 L/min total inlet capacity.For machines with 200+L/min pump flow,consider Walvoil SD8 or SD14 series valves.

　　Load-sensing or pressure-compensated systems requiring closed-center valve architecture.Select Walvoil DPX or SPM series closed-center sectional valves instead,which provide load-independent flow control with variable displacement piston pumps.

　　Electro-proportional remote control requirements where joysticks must be integrated into armrest panels or ISOBUS systems.The KG3-160 is purely mechanical;for electro-hydraulic actuation,specify the SD5 section bodies with EH-EP proportional solenoid operators.

　　FAQ

　　1.Can I add an extra section later,or swap a section for a different flow rating?

　　Yes.The sectional construction allows you to unbolt the tie rods and insert a new spool section at any position in the stack.Replacement 18 L/min and 28 L/min sections are stocked separately,and you can reorder the sequence to suit a new attachment or function.We keep individual sections,seals,and tie rod kits available for field retrofits.

　　2.What is the difference between a sectional and monoblock valve,and why choose sectional?

　　A monoblock valve is cast as one piece;all spools and flow paths are fixed and cannot be changed.A sectional valve builds the assembly from individual spool blocks bolted together.You choose sectional when you need the flexibility to add functions later,swap a damaged section without replacing the entire valve,or configure different flow ratings per section to match each cylinder’s speed.

　　3.Does the KG3-160 joystick come with cables,and what cable length is available?

　　We supply the valve assembly and the KG3-160 control head as a matched set,but control cables are ordered separately because the required length depends on the routing distance between the operator station and the valve mounting location.Standard cable lengths range from 1.2 m to 4.5 m in 300 mm increments.We recommend measuring the cable path before ordering.

　　4.How much does this valve cost,and does the price include all six sections?

　　A complete SD5/6-P assembly with the specified five 18 L/min sections,one 28 L/min section,and fully assembled tie rods ranges from 7,500to12,000 per unit.Prices fluctuate with foundry alloy costs and regional freight.Contact Beijing Zhongping Technology for a formal quotation including cables and the KG3-160 joystick.

　　5.What hydraulic oil and filtration do I need to run this valve reliably?

　　Use mineral-based hydraulic oil ISO VG 32,46,or 68 within the 15–100 cSt viscosity range.Filtration must meet ISO 4406 cleanliness code 21/19/16 as a minimum;we strongly recommend 18/16/13 to achieve rated service life.Failure to maintain oil cleanliness is the primary cause of spool sticking and internal leakage.

　　6.Can I convert this valve from cable joystick to electric solenoid control later?

　　The SD5 valve body is not designed for field conversion between mechanical and solenoid actuation—the spool end housing and centering spring assembly differ.If you anticipate a future need for electro-proportional control,contact Beijing Zhongping Technology before ordering to evaluate the SD5-EH variant.

　　7.Is the valve pre-assembled and tested before shipping?

　　Every valve leaves the factory fully assembled,torqued to specification,and tested for internal leakage at 1.5 times rated pressure.A test certificate is supplied with each unit.We do not ship unassembled section kits unless you explicitly request a build-your-own configuration for prototyping.

　　8.How do I identify a spare seal kit or order replacement seals for one leaking section?

　　Each spool section has a dedicated seal kit part number listed on the assembly drawing shipped with the valve.We stock individual section seal kits and full-valve seal kits.Leakage from the spool end cap or between sections is typically resolved by replacing the O-ring and backup ring without removing the entire valve from the machine.

　　9.What lead time should I plan for,and do you keep standard configurations in stock?

　　Standard 4-section to 6-section SD5 assemblies with 18 L/min sections are often in regional stock and ship within 5 working days.The exact 18L/18L/18L/18L/18L/28L configuration may extend lead time to 6–8 weeks.Confirm with Beijing Zhongping Technology at time of order.

　　10.What happens if a section seizes or the joystick feels stiff after winter storage?

　　Spool seizure is almost always caused by contaminated oil or moisture-induced corrosion.First,drain and replace the hydraulic oil,then operate the valve through full stroke to flush contaminants.If stiffness persists,remove the suspect spool,clean with mineral spirits,and inspect for scoring.We provide a troubleshooting guide and can expedite a replacement section if the spool surface is damaged.