Fast-closing plastic check valves with a spring-assisted disc, mountable in any orientation, with selectable cracking pressure for pumped, dosing, and surge-sensitive lines.
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 Spring Loaded Plastic Check Valves Manufacturers and Custom Spring Loaded 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
Spring loaded plastic check valves hold a disc or poppet against its seat with a light spring. Forward pressure compresses the spring and lifts the element; as soon as flow slows, the spring pushes the element back before the flow can reverse. Because the spring, not gravity or back pressure, does the closing, the valve works in any orientation and closes quickly enough to reduce water hammer in pumped systems.
The spring rate sets the cracking pressure, the minimum forward pressure needed to open the valve. Light springs give a low cracking pressure for gravity-fed lines, while firmer springs add backpressure for dosing pumps and injection points. The spring is usually stainless steel or a plastic-coated alloy sealed away from the fluid wherever the chemistry requires it.
Pumped lines, dosing points, and mixed orientations that need fast, positive closing.
The spring must resist the fluid as well as the body, so spring material is chosen with the chemistry in mind.
| Component | Options | Selection Basis | Notes |
| Body | PVC-U, CPVC, PP, PVDF | Fluid chemistry and temperature | Any-orientation mounting |
| Spring | Stainless steel or plastic-coated alloy | Fluid corrosiveness | Plastic coating for aggressive fluids |
| Seal | EPDM, FPM | Fluid and temperature | Seat O-ring |
| Disc / Poppet | Matched plastic | Weight and chemical resistance | Guided by the body |
| Item | Description |
| Valve Type | Spring loaded plastic check valve |
| Body Material | PVC-U, CPVC, PP, or PVDF |
| Seal Material | EPDM or FPM |
| Spring Material | Stainless steel or plastic-coated alloy |
| Size Range | DN15 – DN100 (1/2 inch – 4 inch) |
| End Connection | Socket, threaded, or flanged |
| Working Pressure | Up to 235 psi (16 bar) at 20°C, rating decreases with temperature |
| Working Temperature | 0°C to 90°C, material dependent |
| Cracking Pressure | Selectable by spring rate, from low to several psi |
| Orientation | Any |
A spring replaces gravity, trading some pressure loss for faster, orientation-free closing.
| Factor | Spring-Loaded Check | Gravity-Closing Check |
| Orientation | Any | Horizontal or vertical upward only |
| Closing Speed | Fast, spring-assisted | Slower, depends on gravity and back pressure |
| Cracking Pressure | Set by spring rate | Very low |
| Pressure Loss | Higher because of the spring | Lower |
| Water Hammer | Reduced by fast closing | Can slam on rapid reversal |
| Best Use | Pumped, dosing, and mixed-orientation lines | Steady-flow, gravity-aided lines |
A spring holds the disc against the seat until forward pressure compresses it and lifts the disc.
Cracking pressure is checked against the specified spring rate in addition to sealing.
The spring sets how much forward pressure is needed to open the valve.
| Spring Option | Best Suited For | Key Characteristics |
| Light Spring | Gravity-fed or low-pressure lines | Low cracking pressure, little head loss |
| Standard Spring | General pumped service | Balanced opening pressure and fast closing |
| Firm Spring | Dosing and injection points | Holds backpressure at the pump discharge |
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, air freight for urgent shipments, and express courier for samples. Valves are cartoned and palletized.
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 hinged disc that swings clear of the
Overview A free-moving ball that seals the line
Overview Automatic backflow prevention in corros
Overview A raised-seat body geometry that reduce
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, fluid, and cracking pressure needs, and get a spring and material 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 Spring Loaded Plastic Check Valves Manufacturers
