Check valve fig. 407A, double-disc, wafer-type, straight DN100PN16 407A100C54

Application and Operating Principle in Water Installations

The check valve fig. 407A is a key component for installation safety, designed to automatically prevent backflow in water supply, heating, and district heating systems. Its dual-disc (butterfly) construction allows for between-flange installation, significantly reducing installation time and saving space in compact technical cabinets. Thanks to the use of a stainless steel spring, the valve reacts immediately to changes in flow direction, closing even in the absence of pressure or in vertical positions – which is invaluable in pump systems where water backflow is a risk.

It is worth noting the versatility of this solution: it performs well in circuits with cold water as well as in systems using glycol or other neutral media. The maximum operating temperature is +100°C (with a temporary increase up to 110°C), and the working pressure is 16 bar. This makes this model ideal for applications in district heating and fire protection installations, where operating conditions can be demanding.

Construction Materials and Corrosion Resistance

A key advantage of the version designated with code C54 is the use of stainless steel not only for the closing discs but also for the spring and pin. In standard valves, these components are often made of galvanized or plain steel, which in humid environments can lead to corrosion and mechanism seizure. Here, we have full chemical resistance of moving parts (AISI304), extending the device's service life even in more aggressive environments.

The body is made of grey cast iron EN GJL-250, coated with an epoxy layer – this provides additional protection against rusting from both the external and internal sides (where it contacts the medium). The seals are made of EPDM, a material known for its thermal and chemical resistance. This combination of materials guarantees tightness for years without the need for frequent inspections or seal replacements.

Installation and Operational Parameters

Valve installation is simple thanks to standard between-flange dimensions compliant with EN558-49. For DN100 diameter, the device weighs approximately 4.35 kg, facilitating handling during installation work without the need for heavy lifting equipment. The valve can be installed both horizontally and vertically – provided that in vertical installation, the flow is directed upwards.

To facilitate installation planning, it is worth noting key data: nominal diameter is DN 100 (4 inches) at PN 16 pressure (16 bar). The body is made of grey cast iron EN GJL-250 with an epoxy coating, while the discs and spring are made of stainless steel AISI304 (1.4301). The device handles temperatures up to +100°C (temporarily up to +110°C) and features a flow coefficient Kvs of 200 m³/h. Acceptable media include water, glycol, and other neutral media, connected between flanges according to PN-EN 1092.

Thanks to its short installation length (standard for the fig. 407 series), this valve minimizes pressure losses in the system while ensuring effective protection against medium backflow. It is a "plug-and-play" solution for installers seeking reliability without the need for additional accessories or control actuators.