Flanged Gate Valve with Soft Sealing - Series 20.900 - DN 50; L=150mm BRA.20.900

Product detailed description

Flanged gate valves are essential components in industrial and commercial HVAC systems, where they regulate the flow of fluids in closed-loop circuits. These valves are commonly used in central heating plants, building services, and process engineering applications. Installers typically work with these valves in systems requiring isolation of sections for maintenance or during system commissioning. They are particularly suited for environments where tight sealing is required, such as in water distribution and waste water management.

The design of the valve allows for smooth, full-bore flow control, which minimises pressure drop and ensures efficient operation. The flanged connections enable secure and leak-free installation in pipe systems, making them ideal for use in both new builds and system retrofits. The valve is not suitable for steam or oily liquids due to the properties of the sealing materials used.

Technical parameters

Installation and connection

Installation of the flanged gate valve requires alignment of the flange faces and the use of appropriate gaskets to ensure a leak-free connection. The valve should be mounted in a position that allows for easy access to the handwheel and stem. The flange type conforms to STN EN 1092-1 standards, and the connection must be verified for correct torque application during tightening. A common mistake during installation is misalignment of the flange faces, which can lead to leakage or uneven wear of the sealing surfaces. The valve should be installed in a straight section of the pipeline to avoid stress on the body or stem.

Compatibility and accessories

This valve is compatible with standard flanged piping systems using PN 16-rated components. It is intended for use with water-based fluids and is not suitable for steam or hydrocarbon-based media. When integrating the valve into a system, ensure that the associated piping and fittings are also rated for the same pressure and temperature range. No additional accessories are required for basic operation, though isolation tools or lifting equipment may be necessary for larger installations.

Technical background for designers

The gate valve operates by moving a wedge-shaped disc vertically within the body to open or close the flow path. The soft sealing mechanism uses an EPDM-coated wedge and NBR O-rings to create a tight seal when the valve is closed. The body material, ductile iron GJS 500-7, provides high strength and resistance to deformation under pressure. The stem is made of AISI 420 stainless steel and is fixed to prevent rotation, ensuring long-term reliability. The valve is designed for use in systems operating between -10°C and +85°C and must be selected based on the fluid type and expected operating conditions to ensure longevity and performance.

Service and operation

Regular inspection of the valve is recommended to ensure continued performance. Check for signs of leakage around the flange and stem seals, and verify that the handwheel operates smoothly without excessive resistance. The stem should remain non-rotating during operation, and any binding or stiffness may indicate the need for lubrication or adjustment. No scheduled service intervals are specified in the technical documentation, and maintenance should be performed as needed based on visual and operational checks.

Frequently asked questions

Can the valve be used in steam systems?
No, the valve is not suitable for steam due to the properties of the EPDM sealing material, which degrades under high-temperature steam conditions.

Is the valve suitable for use with oily fluids?
No, the valve is not recommended for use with oils or hydrocarbon-based media, as these substances can degrade the sealing components over time.

What is the maximum operating temperature?
The valve is rated for operation up to +85°C, beyond which the sealing integrity may be compromised.

Can the valve be used in reverse flow direction?
Yes, the valve is symmetrical in design and can be installed with the flow in either direction without affecting performance.