Shijiazhuang Laiye Import& Export Trading Co., Ltd. is one of the leading manufacturers and suppliers of sd8 — 80 l/min manual sectional directional valve in China, also supports customized service. If you're going to wholesale high quality sd8 — 80 l/min manual sectional directional valve made in China, welcome to get pricelist from our factory.
The SD8 is a sectional valve - built from individual sections bolted together, not a single casting like the SD5.
The main reason people choose sectional over monoblock is straightforward: flexibility. With a sectional valve, you're not locked into a fixed configuration. Start with what you need today. Add more sections later if your machine changes or you add new functions. You can't do that with a monoblock.
The flow rating is 80 L/min at 315 bar. That puts it in a practical middle zone - enough for equipment that's outgrown smaller monoblock valves, without jumping all the way to 100 L/min.
For equipment in this range, the SD8 - 80 L/min Manual Sectional Directional Valve gives you room to grow without overbuying today.
What to Know About This Valve
The 80 L/min Sweet Spot
A lot of smaller equipment runs on 40-50 L/min valves. They work fine until you add a new attachment or push the machine harder. Then suddenly the valve is the bottleneck. The SD8 gives you 80 L/min - nearly double what many compact monoblocks offer - without the size and cost of a 100+ L/min valve. It's a practical step up for machines that need more flow but don't need the full DCV series capacity.
Pressure - 315 Bar
315 bar operating pressure. That's less than the 350 bar of the DCV series, but more than the SD5's 250 bar. The equipment this valve typically ends up on doesn't need 350 bar. What it does need is consistent pressure without drop-off under load.
Leakage Control
15 cc/min at 160 bar, 50°C. Same spec across all our valves. We hold the same clearance tolerances regardless of size. The number doesn't get looser just because the valve is smaller or larger. It's a consistent standard.
Surface Treatment
Phosphating. It's a chemical conversion coating that bonds with the metal. Unlike paint, it doesn't peel when scratched. Passes 48-hour salt spray.
Sectional Flexibility
The valve is built from individual sections - an inlet section, working sections, an outlet section - held together by through-bolts. Each working section contains a spool, springs, and detent. The lever connects directly to the spool. You can start with 3 sections and add more later.
The SD8 - 80 L/min Manual Sectional Directional Valve is straightforward, built to last, and designed to adapt as your needs change.
How It Works
Push the lever. The spool slides inside its bore. Internal passages open and close. Oil gets routed from P to either A or B. The cylinder extends or retracts. Let go of the lever, the springs push the spool back to center. Flow stops.
That's the whole sequence. No wires, no sensors, no programming. Just mechanical control that works every time.
The sectional construction is simple to understand:
Inlet section - oil enters from the pump through the P port
Working sections - one per function, each with its own spool, springs, and detent
Outlet section - closes the end of the stack
Through-bolts - run the length of the stack, holding everything together
Specifications
| Parameter | Value |
|---|---|
| Control method | Manual |
| Pressure medium | Mineral oil based hydraulic oil |
| Nominal flow | 80 L/min |
| Viscosity range | 12–400 CST |
| Operating pressure | 315 bar (35 MPa) |
| Internal leakage | 15 cc/min @160 bar, 50°C |
| Ambient temperature | -40°C to +80°C |
| Valve structure | Sectional |
| Surface treatment | Phosphating |
| Valve sections | 1 to 12 |
| Rustproof level | 48h neutral salt spray test |
About the Company
Shijiazhuang Laiye Import & Export Trading Co., Ltd. is part of Hebei Wendefu Hydraulic Technology Co., Ltd. We are a manufacturing company, not a trading desk.
We started in 1988 - over 35 years ago. The team is around 200 people, including senior engineers who have been with us for twenty years or more.
We do everything in-house: machining, assembly, testing. Every valve gets tested individually, not as a sample from the batch. Test data is recorded and kept with the serial number. If there's ever an issue, we can trace it back to that specific valve.
Production Process - SD8 Sectional Valve
Raw Material Inspection
Steel and iron castings are inspected upon arrival. Each batch undergoes spectral analysis for material composition and internal defect inspection. Non-conforming materials are rejected.
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Precision Machining
Valve bodies are machined on CNC machining centers. The SD8 is a sectional valve - each working section is machined individually before assembly. Tolerances are held to microns.
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Heat Treatment
Machined bodies undergo heat treatment to relieve internal stress and improve wear resistance and dimensional stability.
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Spool Lapping
Each spool is precision-ground and then fitted to its matching valve body bore. Final lapping is done based on actual clearance measurements. This step directly determines internal leakage performance.
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Surface Treatment
Valve bodies are phosphated. This is a chemical conversion coating, not paint - it bonds with the metal and does not peel off when knocked.
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Assembly
Working sections, inlet section, and outlet section are assembled with through-bolts. Seals are from reputable brands. Torqued to specification.
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Pressure Testing
Every valve is individually tested - not spot-checked. Test items include neutral position internal leakage, pressure drop, lever operating force, and external leakage. Test data is filed with the serial number.
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Final Inspection
Final inspection confirms appearance, marking, and packaging meet requirements. Qualified units go to inventory.
FAQ
Q: What is a sectional valve?
A: Multiple sections bolted together into one stack. Each section controls one function independently. You can add or remove sections as needed.
Q: Can I add sections later after the valve is assembled?
A: Yes. That's the main advantage of a sectional valve. You'll need longer through-bolts and the additional sections. Contact us for an expansion kit with instructions.
Q: Does the SD8 come with a relief valve?
A: The SD8 is a directional valve - it controls flow direction. Pressure relief is handled by a separate relief valve in your hydraulic system.
Q: How do I know if the SD8 is the right size for my machine?
A: Send us your pump displacement, cylinder sizes, and the number of functions you run simultaneously. We can check whether 80 L/min matches your system or if you need a different valve.
Q: Can I replace just one section if it fails?
A: Yes. On a sectional valve, individual sections can be replaced. You'll need to disassemble the stack and reassemble with the new section and the same through-bolts (or longer ones if you're adding sections). We recommend having our team do this unless you're experienced with valve assembly.
Q: What is the mounting orientation?
A: The SD8 can be mounted in any orientation. Horizontal with the lever facing up is recommended for best lever feel and longest spring life.
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