Handwheel-driven diaphragm shutoff and throttling in PVC-U, CPVC, or PP — the base, actuator-free configuration for local industrial process control.
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 Manual Industrial Diaphragm Valves Manufacturers and Custom Manual Industrial Diaphragm 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
Manual industrial diaphragm valves rely on a handwheel-driven compressor to press the flexible diaphragm onto the weir seat, giving the operator direct tactile feedback on seating force and flow position without an actuator, air supply, or electrical connection. Built from PVC-U, CPVC, or PP depending on the process chemistry, this is the base configuration most industrial diaphragm valve installations start from, before any automation is added.
Local, infrequently operated shutoff and throttling points — plant utility isolation, sample lines, equipment bypass valves, and process points that an operator visits routinely as part of a walkdown — are typically better served by a manual valve than by adding actuator cost and complexity. The same weir-type flow path and stem-free diaphragm sealing found on automated versions of the valve is retained, so solids-handling and chemical resistance are unchanged.
Local, operator-accessible shutoff and throttling points are the core application for a manually operated diaphragm valve.
Body material determines chemical compatibility and temperature range, independent of the manual handwheel operation.
| Material | Temperature Range | Typical Strengths | Common Use |
| PVC-U | 0°C to 60°C | Broad acid and alkali resistance, economical | General water treatment and utility isolation |
| CPVC | 0°C to 95°C | Higher temperature ceiling than PVC-U with similar chemical resistance | Hot process water, elevated-temperature chemical lines |
| PP | 0°C to 90°C | Good solvent resistance, lighter than PVC-U | Dosing manifolds, general process piping |
| Item | Description |
| Valve Type | Manually operated weir-type diaphragm valve |
| Body Material | PVC-U, CPVC, or PP |
| Diaphragm Material | EPDM, FPM (Viton), or PTFE-faced EPDM |
| Bonnet Material | Matched to body material or glass-reinforced polypropylene |
| Size Range | DN15 – DN150 (1/2 inch – 6 inch) |
| End Connection | Socket, threaded, or flanged |
| Working Pressure | Up to 150 psi (10 bar) at 20°C, rating decreases with temperature |
| Working Temperature | 0°C to 95°C, material dependent |
| Sealing Performance | Bubble-tight shutoff, suitable for throttling duty |
| Operation | Handwheel, with position indicator on larger sizes |
| Flow Path | Weir-type body with raised seat for reduced diaphragm travel |
Both use the same sealing principle; the choice comes down to cycling frequency and how the valve is accessed.
| Factor | Manual Diaphragm Valve | Actuated Diaphragm Valve |
| Operation | Handwheel, operator present at the valve | Remote or automated, no operator needed at the valve |
| Cost | Lower, no actuator or accessories needed | Higher, includes actuator and mounting hardware |
| Cycling Frequency | Best suited to infrequent operation | Suited to frequent or programmed cycling |
| Response Time | Depends on operator availability | Fast, consistent response to a control signal |
| Infrastructure Needed | None beyond the valve itself | Compressed air or electrical supply to the valve |
| Best Use | Local, routinely accessible shutoff points | Remote, automated, or high-cycle process points |
A handwheel drives the stem and compressor to press the diaphragm onto the weir seat within the body.
Inspection confirms both body pressure integrity and diaphragm sealing performance before packing.
A bonnet interface common across the range accepts a pneumatic or electric actuator without replacing the valve body.
| Operation Type | Best Suited For | Key Characteristics |
| Handwheel | Local, infrequently operated shutoff and throttling | Lowest cost, direct tactile control, no utilities needed |
| Future Pneumatic Actuator | Upgrade path if the line is later automated | Bolts onto the same bonnet interface |
| Future Electric Actuator | Upgrade path for remote or BMS-integrated control | Bolts onto the same bonnet interface |
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 large-volume orders, air freight for time-sensitive shipments, and express courier for samples. Valves are packed in cartons or wooden crates depending on size.
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 The full diaphragm valve range, from bo
Overview Built for corrosive and high-purity flu
Overview A threaded-end diaphragm body sized for
Overview CPVC shutoff engineered for hot water a
Overview Automatic backflow prevention in corros
Overview Lift-type checks designed for upward fl
Overview A reinforced body and bonnet for demand
Overview A raised-seat body geometry that reduce
Overview A diaphragm valve sized and specified f
Share your process fluid, sizing, and connection requirements, and get a material recommendation for your line.
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 Manual Industrial Diaphragm Valves Manufacturers
