Cast iron elbow SML 80/68 (grey cast iron, hubless) 23733

SML socketless cast iron pipe system for modern sewerage

The SML 80/68 cast iron elbow with catalog number 23733 is a component of a socketless system of grey cast iron pipes and fittings, designed for gravity sewerage and drainage installations inside buildings. The product manufactured by the PREIS brand as part of the SML series is part of a proven solution that completely replaced traditional socketed pipes as early as 1982.

Materials and advanced protective coatings

The SML system is made of grey cast iron with flake graphite according to the EN 1561 standard, which ensures a high material density of approximately 7.2 kg/dm³. Each element is coated with specialized epoxy coatings applied through an industrial process.

The external coating in a reddish-brown primer color with a thickness of 40 μm is applied by spraying onto the surface of the pipes and fittings. If necessary, it can be covered with an additional colored lacquer or a coating composition.

The internal coating in an ochre (yellow-brown) color with a thickness of 120 μm is applied by spraying onto the internal surfaces of the elements. Fittings undergo a dip-coating process and are subsequently cured for 45 minutes at a temperature of approximately 180°C. This process creates a high-strength bond between the fitting and the coating.

Performance properties and system advantages

The SML system is characterized by reaction to fire class A2 according to EN 13501, which means the elements are completely non-combustible. In the event of a fire, it maintains its functional properties for many hours - the walls remain impermeable to flames and gases, without cracking or losing their performance capability.

Acoustic protection is one of the most important features of the system. Thanks to the high density of the cast iron and the buffering effect of the rubber seals at the connecting elements, structure-borne noise transmission has been reduced to a minimum. Tests conducted by the Fraunhofer Institut in Stuttgart confirmed very low noise levels - at a flow rate of 4 liters/second, the noise level is less than 10 dB when using a pipe clamp with rubber and a vibration-isolating element.

The system demonstrates high thermal and chemical resistance. The epoxy coating protects against aggressive sewage in the range of pH 2 to pH 12, and the operating temperature can reach up to 80°C. The thermal expansion is only 0.0105 mm/mK, which is comparable to concrete and allows for trouble-free concreting of the pipes.

Practical application and installation

The SML elbow with dimensions 0.15 × 0.09 × 0.13 m weighs 1.18 kg and is used to change the direction of sewage flow at an angle of 68°. The SML system elements are connected to each other using appropriate pipe clamps (clamps, bands, couplings), which ensures the tightness of the connections.

Installation is simple - it does not require special tools or complicated welding or gluing procedures. The system offers time savings due to rapid installation using plug-in connectors and flexibility in routing the installation without the need for precise cutting or fitting of elements.

The product is 100% recyclable, without polluting the natural environment. The products are mainly made from iron scrap, which eliminates the waste of natural resources while maintaining the highest quality parameters confirmed by CE certificates and the RAL-GZ 698 quality mark.