DIN Cast Iron Check Valve

Marine DIN Cast Iron Check Valve

The Marine DIN Cast Iron Check Valve is a robust, high-performance non-return valve, specifically engineered for demanding maritime applications where reliable backflow prevention is critical. Designed for use in seawater, air, and gas systems, this valve ensures unidirectional flow, protecting pumps, compressors, and other sensitive equipment from the damaging effects of reverse flow and pressure surges.

A key feature of this valve is its zinc-free bronze trim (seat and spring). In standard brass or bronze containing zinc, seawater can cause dezincification—a corrosive process where zinc is leached out, leaving a weak, porous copper structure. By specifying zinc-free bronze for the critical internal components, this valve provides superior long-term resistance to this form of corrosion, ensuring reliable sealing and operation throughout its service life.

Designed to DIN Standards for Global Compatibility

Manufactured in full compliance with DIN (Deutsches Institut für Normung) standards, this check valve guarantees dimensional accuracy, performance reliability, and interchangeability with other DIN-standard piping components. The cast iron body provides a durable and cost-effective pressure-containing shell, while the use of graphite gaskets ensures a reliable, long-lasting seal between the body and bonnet, capable of withstanding temperature fluctuations and media variations.

With a PN16 pressure rating and a wide nominal diameter range from DN15 to DN300, this valve series is suitable for a vast array of shipboard and offshore applications, from small auxiliary lines to large seawater cooling mains.

Key Features & Benefits

✅ Zinc-Free Bronze Trim (Seat & Spring): Critically important for seawater applications. The absence of zinc eliminates the risk of dezincification, preserving the structural integrity of the sealing components and ensuring long-term, corrosion-resistant performance.
✅ DIN Standard Compliance: Manufactured to precise DIN standards, guaranteeing dimensional reliability, performance, and compatibility with European and international piping systems.
✅ Durable Cast Iron Construction: The robust body and bonnet provide a strong, pressure-containing shell at a cost-effective price point, ideal for marine utility systems.
✅ Graphite Gasket Material: Provides a reliable, long-lasting, and temperature-resistant seal between the body and bonnet, preventing external leaks.
✅ PN16 Pressure Rating: Suitable for a wide range of standard-pressure marine systems, including cooling water, ballast, and compressed air.
✅ Wide Size Range (DN15-DN300): Offers versatile application across the vessel, from small-bore instrument lines to large-diameter main seawater circuits.
✅ Custom Material Options: Tailored material specifications can be accommodated to meet specific customer requirements or classification society rules.
✅ Strict Quality Assurance: Manufactured under rigorous controls to ensure product reliability and consistent performance.

Technical Specifications

Parameter	Specification
Design Standard	DIN (Deutsches Institut für Normung)
Product Type	Marine Check Valve / Non-Return Valve
Pressure Rating	PN16
Nominal Diameter (DN)	DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN125, DN150, DN200, DN250, DN300
Body & Bonnet Material	Cast Iron
Seat & Spring Material	Zinc-Free Bronze (Critical for Dezincification Prevention)
Bonnet Gasket Material	Graphite
Media	Seawater, Cold/Warm Fresh Water, Compressed Air, Neutral Gases, Other Neutral Media
Applications	Marine Seawater Cooling, Ballast Systems, Compressed Air Lines, Offshore Piping, HVAC

Dimensions & Specifications

CODE	DN	D (mm)	L (mm)	H (mm)	Weight (Kgs)
75 58 71	15	95	130	56	2.1
75 58 72	20	105	150	56	2.7
75 58 73	25	115	160	67	3.8
75 58 74	32	140	180	76	5.5
75 58 75	40	150	200	89	7.4
75 58 76	50	165	230	96	9.5
75 58 77	65	185	290	104	15
75 58 78	80	200	310	124	20
75 58 79	100	220	350	161	29
75 58 80	125	250	400	174	41
75 58 81	150	285	480	197	66
75 58 83	200	340	600	248	111
75 58 84	250	405	730	333	196
75 58 98	300	460	800	375	302

Applications

The Marine DIN Cast Iron Check Valve is the preferred choice for backflow prevention in a wide range of critical marine systems:

Marine Seawater Cooling Systems: Protecting main engines, auxiliary engines, and heat exchangers from backflow.
Shipboard Compressed Air Lines: Preventing reverse flow in control air and service air systems.
Ballast Water Management Systems: Ensuring unidirectional flow in ballast lines.
Offshore Platform Piping Networks: Reliable isolation for process and utility lines.
Neutral Media Handling Systems: For water, air, and other non-aggressive fluids.
Marine HVAC and Utility Systems: General isolation and flow control duties.

Frequently Asked Questions (FAQs)

Q1: Why is “zinc-free bronze” so important for a marine check valve?
A: Standard brass or bronze alloys contain zinc. In a seawater environment, these alloys are susceptible to a corrosive process called dezincification. The zinc is selectively leached out of the alloy, leaving behind a weak, porous, copper-rich structure that loses all mechanical strength. A valve suffering from dezincification can fail suddenly. Zinc-free bronze (often referred to as “red brass” or similar) is specifically formulated to resist this process, ensuring the spring and seat maintain their integrity for the life of the valve.

Q2: What is the difference between a swing check valve and a lift check valve?
A: While the table doesn’t specify the internal type, DIN check valves of this construction are often of the lift check type for smaller sizes and swing check for larger ones.

Lift Check: The disc lifts vertically off the seat. It is generally more compact and suitable for higher pressure and smaller bore applications.
Swing Check: The disc swings on a hinge. It offers a full flow path with lower pressure drop and is common in larger diameters. For your application, the specific design will ensure reliable operation in either horizontal or vertical pipelines (as specified).

Q3: What does PN16 mean?
A: PN stands for “Pressure Nominale” (Nominal Pressure). PN16 is a pressure rating defined by DIN and ISO standards. It indicates that the valve is designed to operate at a maximum working pressure of 16 bar (approximately 232 psi) at a reference temperature (typically 20°C for water). The working pressure must be de-rated for higher temperatures.

Q4: Why are graphite gaskets used instead of rubber or compressed fiber?
A: Graphite gaskets offer several advantages in this application:

High Temperature Resistance: They can withstand the full range of temperatures expected in marine systems, from cold seawater to warm media.
Chemical Resistance: Graphite is inert to most fluids found in marine systems, including seawater, oils, and gases.
Long-Term Seal: Graphite maintains its sealing properties over long periods, resisting creep and relaxation better than some non-asbestos fiber gaskets.

Q5: Can this check valve be installed in a vertical pipeline?
A: The suitability for vertical installation depends on the specific internal design (swing vs. lift) and the manufacturer’s instructions. Generally:

Lift Check Valves: Can often be installed in vertical lines with flow upwards.
Swing Check Valves: Are typically recommended for horizontal installation or vertical lines with upward flow.
Always consult the specific installation and maintenance manual for the valve to ensure correct orientation for proper disc operation and closure.

Q6: What are the “CODE” numbers listed in the dimension table?
A: These CODE numbers (e.g., 75 58 71) are likely the manufacturer’s internal part numbers or a standardized ordering code for each specific valve size. Providing these codes streamlines the ordering process, ensuring you receive the exact DN15 valve with the correct face-to-face dimension (L), flange diameter (D), and material specification when you place an order. It eliminates ambiguity and ensures accurate fulfillment.

Attention please: The description was copied from different cooperating manufacturers. The description may be different with the goods, please check with us when order.

Tag: Our other products
Click here to contact us via whatsapp