Contact Platform Support
Help CenterMarine Diaphragm Check Valve With 1-Year Warranty, Mill Test Report, Cast Iron, EPDM
Product Spotlights
Related Products
-
Standard Compliant Marine Diaphragm Check Valve, DNV BV, Zero Leakage, Threaded ConnectionNegotiableMOQ: 1 Unit -
Marine Diaphragm Check Valve, Cast Iron, EPDM, Zero Leakage, DN15-DN50, PN1.0MPaNegotiableMOQ: 1 Unit
-
316L Marine Silent Check Valve, Threaded Connection, 150LB, Dual Spring Closure, Anti-Slam DesignNegotiableMOQ: 1 Unit
-
304 Stainless Steel Marine Silent Check Valve, DN50-DN200, PN1.6MPa, Wafer Spring Loaded, No Water HammerNegotiableMOQ: 1 Unit
-
Cast Steel Marine Silent Check Valve, Flanged End, DN100-DN300, PN2.5MPa, Silent Closing for Ship PipesNegotiableMOQ: 1 Unit
As a professional manufacturer with years of experience in marine valve production, Shanghai Zhibang Valve Manufacture Co., Ltd is proud to present our Marine Diaphragm Check Valve – a robust, corrosion-resistant solution designed specifically for demanding marine and shipboard applications. Manufactured from high-quality Cast Iron with a durable EPDM diaphragm, this check valve ensures reliable backflow prevention, minimal pressure loss, and long service life even in seawater, ballast, and cooling water systems. Every valve comes with a 1-Year Warranty and a comprehensive Mill Test Report, giving you full traceability and peace of mind.
Our diaphragm check valve offers a unique combination of simplicity and performance. The flexible EPDM diaphragm provides bubble-tight sealing at low back pressures, while the cast iron body withstands high mechanical loads and harsh marine environments. Whether you are retrofitting existing pipelines or building new vessels, this valve is a cost-effective and reliable choice that meets international standards.
Key Features & Benefits
- Durable Cast Iron Body – Offers excellent strength and corrosion resistance for marine service, with optional epoxy coating for enhanced protection.
- EPDM Diaphragm – Provides superior sealing performance, resistant to seawater, ozone, and a wide temperature range (-20°C to +120°C).
- Non-Slam Design – The diaphragm dampens flow reversal, preventing water hammer and protecting downstream equipment.
- Low Pressure Drop – Full bore design minimizes flow resistance, reducing energy consumption in pumping systems.
- Easy Maintenance – The top-entry design allows quick inspection and replacement of the diaphragm without removing the valve from the pipeline.
- Mill Test Report Included – Each valve is individually tested and supplied with a documented report for quality assurance.
- 1-Year Warranty – Backed by our commitment to quality, covering material and workmanship defects.
- ISO9001 Certified Factory – Our manufacturing processes follow strict quality control procedures, ensuring consistent product reliability.
Technical Specifications
| Material | Cast Iron (GG25 / ASTM A126 Class B) |
| Diaphragm Material | EPDM (optional: NBR, Viton) |
| Size Range | DN50 – DN600 (2" – 24") – customizable on request |
| Pressure Rating | PN10/16, Class 150 (higher ratings available) |
| Connection | Flanged (DIN, ANSI, JIS) – other types upon request |
| Operating Temperature | -20°C to +120°C (EPDM) |
| Media | Seawater, fresh water, cooling water, ballast, bilge, and mild chemicals |
| Cracking Pressure | Very low (0.005 – 0.01 MPa) |
Why Choose Our Marine Diaphragm Check Valve? Unlike traditional swing check or spring-loaded valves, the diaphragm design eliminates metal-to-metal contact, reducing wear and noise. The flexible EPDM membrane responds instantly to flow changes, providing reliable closure without slamming. This is especially critical in ship piping systems where pressure surges can damage pumps and instruments. Additionally, the valve’s smooth internal profile prevents fouling and accumulation of debris, reducing maintenance intervals.
Our factory utilizes advanced casting and machining technologies to ensure dimensional accuracy and consistent quality. Each valve undergoes a hydrostatic shell test and a seat leakage test before shipment. The included Mill Test Report provides a detailed record of material composition and mechanical properties, giving engineers and procurement professionals the documentation they need for project approval.
Trusted by Global Marine Industry
Shanghai Zhibang Valve Manufacture Co., Ltd. (established in 2016) has grown into a reliable partner serving over a dozen countries and regions including North America, South America, Western Europe, Southeast Asia, and the Middle East. With an annual export value of US$1 – US$1.5 million, we are committed to providing high-quality valves backed by our ISO9001:2015 quality management system. We ship from major ports (Shanghai, Guangzhou, Hong Kong, Beijing) to any destination worldwide.
Our team of experienced engineers is available to assist with custom requirements, such as special coatings, non-standard flange drilling, or alternative diaphragm materials. We also offer OEM/ODM services for clients who need branded products. With a 1-year warranty and responsive after-sales support, you can buy with confidence.
Ready to upgrade your marine fluid control? Contact us today for a quote or technical datasheet. We are eager to discuss your project and provide the best valve solution.
Frequently Asked Questions (FAQ)
-
Q: What is the main advantage of a diaphragm check valve over a swing check valve?
A: The diaphragm check valve uses a flexible rubber membrane that closes quickly and gently, eliminating water hammer and noise. It is also less prone to jamming or sticking in dirty fluids, making it ideal for marine systems like ballast water or cooling water. -
Q: Can this valve be used for seawater applications?
A: Yes. The cast iron body with optional epoxy coating and the EPDM diaphragm are both highly resistant to seawater corrosion. For even more aggressive chemical media, we offer alternative elastomers like Viton. -
Q: What sizes and pressure classes are available?
A: Standard sizes range from DN50 to DN600 (2" to 24"), with pressure ratings up to PN16 or Class 150. Larger sizes and higher pressure ratings (Class 300) are available as special orders. -
Q: Does the valve come with a test certificate?
A: Absolutely. Every valve is hydrostatically tested and supplied with a Mill Test Report (MTR) certifying material composition and mechanical properties. Additional third-party inspection (e.g., by Lloyd’s or DNV) can be arranged upon request. -
Q: How does the 1-year warranty work?
A: The warranty covers any manufacturing defects in material or workmanship during normal use for one year from the date of shipment. We replace or repair faulty valves free of charge (excluding shipping costs). -
Q: Is the valve suitable for vertical mounting?
A: Yes, the diaphragm check valve can be installed in any orientation – horizontal, vertical, or inclined – without affecting its sealing performance. However, for best longevity we recommend horizontal installation with the diaphragm access port facing upward. -
Q: Can I get a custom flange drilling pattern?
A: Yes. We can customize flange dimensions according to your requirements, including DIN, ANSI, JIS, or any special standard. Please provide your specifications when placing the order. -
Q: How long is the lead time?
A: Standard sizes are typically shipped within 15–25 working days. Custom orders may require 30–40 working days depending on complexity. We will confirm the lead time upon receipt of your inquiry.
Send Inquiry to This Supplier
You May Also Like
-
Carbon Steel Marine Silent Check Valve, PN4.0MPa, DN80-DN250, Lug Style, Spring Assisted, Non-ReturnNegotiableMOQ: 1 Unit
-
Ductile Iron Marine Silent Check Valve, Wafer Type, DN40-DN150, PN1.0MPa, Soft Seal, Low Pressure DropNegotiableMOQ: 1 Unit
-
Marine Silent Check Valve With 18-Month Warranty, Factory Mill Test Report, DN50-DN300, PN10-PN40NegotiableMOQ: 1 Unit
-
Marine Silent Check Valve for Shipboard Freshwater Systems, 304 SS, DN65, PN16, Anti-SurgeNegotiableMOQ: 1 Unit
-
Bronze Marine Silent Check Valve, 1-4 Inch, 300LB, Threaded Ends, Compact Body, Silent OperationNegotiableMOQ: 1 Unit
-
Silent Check Valve for Ballast Water Treatment, 316L, DN200, Flanged, Resilient Seal, IMO CompliantNegotiableMOQ: 1 Unit
-
Zero Leakage Marine Diaphragm Check Valve, Cast Iron Body, EPDM, DN15-DN50, PN1.0MPaNegotiableMOQ: 1 Unit
-
Standard Compliant Marine Silent Check Valve, Free Replacement for Defects, Cast Body, Wafer ConnectionNegotiableMOQ: 1 Unit
-
1 Year Warranty, Marine Slow Closing Check Valve, Cast Steel, DN50-DN300, PN1.0-4.0MPa, Mill Test Report AvailableNegotiableMOQ: 1 Unit
-
Dual Plate Marine Slow Closing Check Valve, Counterweight Type, DN100-DN300, PN16, Flanged Connection, LR ABS ApprovedNegotiableMOQ: 1 Unit
