Walvoil SD5/4-P(JG3-160)/18L/18L/18L/18L/AET is a 4-section heavy duty hydraulic valve in a monoblock directional control valve format.As part of the designed monoblock valves SD5 series,it features a nominal flow rate of 45 L/min and maximum operating pressure of 315 bar.Suited for agricultural machinery,material handling equipment,and construction attachments,this valve controls up to four double-acting hydraulic circuits.

　　What Is a Heavy-Duty Monoblock Valve?

　　A heavy-duty monoblock valve is a directional control valve where all spool sections and fluid galleries are cast into a single,rigid housing,as opposed to sectional valves assembled from individual modules.This construction eliminates external seals between sections,enhancing structural integrity and eliminating potential leak paths in high-pressure hydraulic systems.

　　The Walvoil SD5 series is a family of manually operated,open-center monoblock valves designed for medium-flow mobile hydraulic applications.This specific model is a 4-section valve,meaning it integrates four independent spools to control four separate hydraulic functions.The"JG3-160"designation in the model code identifies a 160 bar main relief valve setting,with each"18L"segment defining the specific spool configuration for each work section.

　　Key Specifications

　　Valve Series:Walvoil SD5

　　Configuration:4-Section Monoblock

　　Nominal Flow Rate:45 L/min(12 US gpm)

　　Maximum Operating Pressure(Parallel/Tandem Circuit):315 bar(4600 psi)

　　Main Relief Valve Setting:160 bar

　　Number of Work Sections:4

　　Spool Configuration per Section:18L(Double-acting,spring return to neutral)

　　Circuit Type:Open Center,Parallel

　　Control Method:Manual Lever

　　Work Port(A/B)Thread Size:G 3/8"BSPP

　　Inlet(P)and Tank(T)Port Thread:G 3/8"BSPP

　　Spool Diameter:16 mm

　　Spool Pitch(Center-to-Center):37 mm

　　Maximum Tank Port Pressure:25 bar

　　Overall Length(E):211.5 mm

　　Lever Pivot Distance(F):184 mm

　　Unit Weight:8.49 kg

　　Fluid Compatibility:Mineral oil,viscosity 46 cSt at 40°C

　　Filtration Requirement:ISO 4406 20/18/15 or better

　　Ambient Operating Temperature Range:-20°C to+80°C

　　Material:Cast iron valve body,steel spools,aluminum lever housing

　　Approvals/Certifications:Manufactured in Italy;meets ISO 4401 port interface standards.

　　Compatible Fluids:Mineral oil-based hydraulic fluids

　　Technical Highlights

　　Single-piece cast iron body eliminates potential leak paths.The monoblock construction integrates all four spool bores and internal galleries into one casting.This design removes the need for tie rods and inter-section O-rings,ensuring long-term structural rigidity and leak-free operation under cyclic pressure loads up to 315 bar.

　　160 bar main relief valve protects downstream components.The integrated main pressure relief valve is set to 160 bar as indicated by the model code.This valve limits maximum system pressure to prevent damage to pumps,hoses,and actuators in the event of overloading or cylinder stall conditions.

　　Parallel circuit configuration enables simultaneous operation.The open-center parallel gallery supplies equal flow to all four work sections.This allows an operator to actuate multiple functions at once—such as lifting and tilting a loader bucket—with flow proportionally divided among the active spools.

　　Interchangeable 16 mm spools simplify maintenance and reconfiguration.Each work section accepts a standard 16 mm spool,which can be replaced or upgraded without removing the entire valve from the machine.This modularity within the monoblock body supports field serviceability and future function changes.

　　Low tank port pressure requirement ensures reliable operation.The maximum allowable pressure on the tank gallery is 25 bar.Systems with high backpressure from return line filters or oil coolers must be verified to remain below this threshold to avoid spool shifting issues or premature seal wear.

　　Applications

　　Agricultural machinery(Harvesting Machines,Baling Machines):Controls hydraulic cylinders for header positioning,reel speed adjustment,and bale chamber functions.The parallel circuit design allows simultaneous operation of multiple functions,reducing cycle times during field operations.

　　Small front loaders and compact tractors:Manages lift,tilt,and auxiliary attachment circuits on sub-100 hp tractors and skid steer loaders.The 45 L/min flow capacity matches the implement pump output on most compact and utility-class agricultural tractors.

　　Construction attachments(Brushcutters,Truck Mounted Cranes):Provides directional control for hydraulic motors on rotary brushcutters and swing/lift functions on light-duty truck cranes.The monoblock construction withstands vibration and shock loads common in construction environments.

　　Conveyors and material handling systems:Directs flow to hydraulic motors driving belt conveyors,augers,and transfer carts.The 18L spool configuration with spring return to neutral ensures the system defaults to a safe stopped state when the operator releases the lever.

　　Trailers and log splitters:Functions as a primary control valve for hydraulic log splitters and dump trailers.The open-center design allows pump flow to circulate to tank at low pressure when all spools are in neutral,minimizing heat generation during idle periods.

　　Municipal and viticulture equipment:Operates attachments on vineyard tractors,street sweepers,and roadside mowing equipment.The valve‘s compact 211.5 mm overall length and 8.49 kg weight facilitate installation in space-constrained equipment frames.

　　Selection Guidance

　　Suitable applications:

　　Mobile hydraulic systems with implement pump flows between 30 L/min and 45 L/min

　　Open-center hydraulic circuits where flow circulates to tank at neutral position

　　Machines requiring control of up to four double-acting hydraulic cylinders or motors

　　Applications where structural rigidity and leak resistance are prioritized over expandability

　　Not recommended for:

　　Closed-center or load-sensing hydraulic systems.The SD5 series is designed for open-center circuits.For closed-center or load-sensing applications,consider Walvoil SDM or DPM series valves,which offer pressure-compensated flow control.

　　Systems requiring flow rates exceeding 45 L/min.Operating the SD5 above its nominal flow rating produces excessive pressure drop and heat generation.For 70 L/min to 160 L/min applications,select a Walvoil SD11,SD14,or SD18 series valve.

　　Machines needing more than 7 work sections.The SD5 platform supports a maximum of 7 sections.Applications requiring 8 or more functions should consider Walvoil SD6 or SDS series sectional valves,which offer unlimited stackable configurations.

　　FAQ

　　1.What is the weight and dimensions of the Walvoil SD5/4-P(JG3-160)valve?

　　The valve measures 211.5 mm in overall length(E dimension)with a lever pivot distance of 184 mm(F dimension).Total unit weight is 8.49 kg,per manufacturer datasheet.

　　2.What is the delivery time or lead time for the SD5/4-P(JG3-160)?

　　We dispatch standard SD5 configurations from stock within 48 hours of order confirmation.Custom spool arrangements or specific relief valve settings require 3 to 4 weeks for factory configuration and testing.

　　3.Is the SD5/4-P(JG3-160)in stock and available for shipment?

　　We maintain inventory of popular SD5 configurations at Beijing Zhongping Technology.Stock availability for the SD5/4-P(JG3-160)configuration is confirmed at time of quotation.

　　4.What do the"18L"and"JG3-160"codes mean in the SD5/4-P(JG3-160)model number?

　　"JG3-160"designates the main relief valve type and its pressure setting of 160 bar."18L"specifies the spool type for each work section—a double-acting spool with spring return to neutral from both actuated positions.

　　5.How much does the Walvoil SD5/4-P(JG3-160)cost?What is the price range?

　　The SD5/4-P(JG3-160)typically ranges from$750 to$1,200 USD per unit depending on configuration and order volume.Prices fluctuate due to exchange rates,tariffs,and factory adjustments.For an accurate quotation with current pricing,contact Beijing Zhongping Technology directly.

　　6.What payment terms do you accept for purchasing Walvoil SD5 valves?

　　We accept bank wire transfer(T/T),major credit cards,and PayPal for orders under$5,000 USD.For qualified corporate accounts,Beijing Zhongping Technology offers net 30 payment terms upon credit approval.

　　7.What are the port thread sizes and connection specifications for the SD5/4-P(JG3-160)?

　　All work ports(A1/B1 through A4/B4),inlet port(P),and tank port(T)are G 3/8"BSPP threads.This standard British Standard Pipe Parallel thread requires bonded seal washers or O-ring face seal fittings for leak-free connections.

　　8.What is the return policy and warranty period for the SD5/4-P(JG3-160)?

　　We provide a 2-year warranty against manufacturing defects on all Walvoil SD5 valves.Returns require prior authorization and are subject to a 20%restocking fee.Beijing Zhongping Technology processes RMA requests within 48 business hours of receipt.

　　9.How do I replace or service a Walvoil SD5 valve if it becomes discontinued or obsolete?

　　The Walvoil SD5 series is an active product line with full parts availability.Replacement spools,seal kits,and lever assemblies are stocked for immediate shipment.For system upgrades,Beijing Zhongping Technology provides cross-reference assistance to SD11 or SD18 series valves for higher flow requirements.

　　10.Can the SD5/4-P(JG3-160)operate at 45 L/min and 315 bar simultaneously?

　　The maximum pressure rating of 315 bar applies to the valve body and internal galleries.The actual working pressure is limited by the 160 bar main relief valve setting.The nominal flow rating of 45 L/min represents the maximum recommended continuous flow;exceeding this value increases pressure drop and may cause premature spool wear.