Hinged-disc plastic check valves with a full-bore flow path and low pressure loss, for horizontal lines and upward vertical flow in water and chemical service.
Ningbo Baodi Plastic Valve Co., Ltd. traces its origins back to 1979, with its predecessors being Zhenhai Chemical Valve Factory and Beilun Plastic Valve Factory. The company is one of the earliest Swing Type Plastic Check Valves Manufacturers and Custom Swing Type Plastic Check Valves Factory in China to design and produce industrial plastic valves and receive acceptance from the Ministry of Chemical Industry. In 1979, the company manufactured its first plastic diaphragm valve, which passed the technical appraisal of the Ministry of Chemical Industry in 1983. In 1992, the company invented the one-piece flange ball valve, a structural design that has since become the most widely used plastic valve product in chemical-related industries. The development history of the company and its predecessors also represents an important chapter in the application of plastic valves in China's industrial production.
In 2006, the company expanded its product line to cover industrial plastic pipes and fittings, becoming one of the first domestic enterprises to apply CPVC material in the production of industrial-grade piping valves. Over more than 40 years since its establishment, the company has designed and manufactured various plastic valves for the most demanding industries. It has served tens of thousands of enterprises both domestically and internationally, exporting to more than 60 countries, and has consistently remained a leading manufacturer of industrial thermoplastic valves and piping systems. Our professional service and stable quality have always been well received and recognized by customers.
Baodi ranks among the global leaders in the number of product categories, capable of fully covering industrial plastic pipe and valve requirements. The company has obtained ISO 9001, ISO 14001, and ISO 45001 system certifications, as well as the national special equipment pressure piping component manufacturing license. It is recognized as a National High-Tech Enterprise and a Ningbo City Specialized and Sophisticated Enterprise. Baodi is a principal drafter of the national standard for plastic diaphragm valves and the chemical industry standards for plastic diaphragm valves, plastic ball valves, and plastic check valves.
Design Idea
2D Drawing
3D Modeling
Mold Fabrication
Prototype Testing
Full-scale production
A swing type plastic check valve carries a disc on a hinge pin at the top of the body. Forward flow pushes the disc up and out of the way, leaving a nearly unobstructed passage. When the flow stops or reverses, gravity and back pressure swing the disc down onto the seat, sealing the line. The straight-through path gives very low pressure loss compared with lift or spring designs.
Swing checks work best in horizontal lines, where gravity returns the disc to the seat, and in vertical lines with upward flow. They need enough velocity to hold the disc fully open and avoid flutter, and they close more slowly than spring-loaded valves, so they suit systems with steady flow and moderate pump cycling. Flanged, socket, and threaded versions are available in PVC-U, CPVC, and PP.
Medium and large lines with steady flow and clean fluids are the natural fit for a swing check.
Body material sets chemical resistance and temperature; the seat elastomer governs sealing with the disc.
| Material | Temperature Range | Typical Strengths | Common Use |
| PVC-U | 0°C to 60°C | Economical, broad chemical resistance | Water and general chemical lines |
| CPVC | 0°C to 90°C | Higher temperature tolerance | Hot water and elevated-temperature chemicals |
| PP | 0°C to 80°C | Lightweight, solvent resistant | Process and dosing lines |
| Item | Description |
| Valve Type | Swing type plastic check valve |
| Body Material | PVC-U, CPVC, or PP |
| Seat Material | EPDM or FPM |
| Size Range | DN50 – DN300 (2 inch – 12 inch) |
| End Connection | Flanged, socket, or threaded |
| Working Pressure | Up to 150 psi (10 bar) at 20°C, rating decreases with temperature |
| Working Temperature | 0°C to 90°C, material dependent |
| Cracking Pressure | Low, typically a fraction of a psi |
| Orientation | Horizontal, or vertical with upward flow |
| Closing Behavior | Gravity and back pressure; slower than spring-loaded designs |
Both prevent backflow; they differ in pressure loss, closing speed, and where they can be mounted.
| Factor | Swing Check | Spring-Loaded Check |
| Pressure Loss | Very low, full-bore path | Higher, element sits in the flow |
| Closing Speed | Slower, can slam on rapid reversal | Fast, spring assists closing |
| Orientation | Horizontal or upward vertical | Any orientation |
| Cracking Pressure | Very low | Set by spring rate |
| Typical Size | Medium to large | Small to medium |
| Best Use | Steady-flow, low-loss lines | Pumped lines needing fast closure |
A hinged disc pivots at the top of the body and seats against an angled seat ring.
Disc swing, hinge freedom, and seat sealing are verified on every swing check.
Small changes to the disc and seat adapt the valve to different line conditions.
| Option | Best Suited For | Key Characteristics |
| Standard Disc | Steady forward flow | Lowest pressure loss |
| Weighted Disc | Lines prone to flow reversal | Faster closing, less slam |
| FPM Seat | Oils and some solvents | Broader chemical range than EPDM |
Payment: T/T (bank transfer), L/C, and PayPal are accepted, with flexible terms for repeat orders. A deposit is typically required to confirm production.
Shipping: Sea freight (FCL/LCL) for bulk orders and air freight for urgent shipments. Larger valves are shipped in wooden crates with the disc secured for transit.
Delivery: Shipment from the nearest available port or airport, with door-to-door, FOB, CIF, or EXW terms on request.
Each valve is covered under a standard warranty against manufacturing defects in material and workmanship, generally valid for 12 months from the shipment date.
Overview A free-moving ball that seals the line
Overview A raised-seat body geometry that reduce
Overview A spring-assisted element that closes f
Overview Automatic backflow prevention in corros
Overview Lift-type checks designed for upward fl
Overview Compressed-air operation for fast, repe
Overview Motor-driven shutoff for remote, wired
Overview A slim wafer body that clamps between s
Overview A reinforced body engineered for the up
Share your size, orientation, flow rate, and fluid, and get a configuration recommendation.
Start your cooperation journey with Baodi
Contact
baodivalve@bdsjfm.com
+86-574-86817753
+86-574-86812190
After-Hours Hotline：
+86-18395898313
NO.42 Yongjiang Road, Beilun,Ningbo city, Zhejiang province,P.R.China
Custom Swing Type Plastic Check Valves Manufacturers
