Cast iron elbow SML 80/88 (grey cast iron, hubless) 13876

Coupling-free system for modern sewerage

The SML 80/88 cast iron bend is a component of a sewerage system made of grey cast iron without a spigot, designed for gravity-fed sewerage and drainage installations inside buildings. The product belongs to the SML series by PREIS and is manufactured in accordance with the requirements of the EN-877 standard.

Material and protective coating

The component is made of high-quality grey cast iron containing flake (lamellar) graphite, which ensures exceptional mechanical strength and service durability. The material is characterized by a density of approximately 7.2 kg/dm³ and high compressive strength - this value is approximately 3-4-times greater than the tensile strength.

The external surface is coated with a reddish-brown primer with a thickness of 40 μm applied by spraying, which can be additionally coated with a standard colored lacquer or a coating composition. The internal surface has a layer of fully cross-linked epoxy resin in an ochre (yellow-brown) color with a thickness of 120 μm, protecting against aggressive sewage.

In the case of fittings, the coating process differs - the colored epoxy coating is applied by immersion to all surfaces and then cured for 45 minutes at a temperature of approximately 180°C. This process creates a durable bond between the fitting and the coating.

Service properties and safety

The SML system is characterized by fire reaction class A2 according to EN 13501 - the components are completely non-combustible and non-toxic. In the event of a fire, they maintain their functional properties for many hours: the walls remain impermeable to flames and gases, do not crack, and do not lose their operational capacity.

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, material sound transmission has been reduced to a minimum. Tests conducted in December 2011 by the Fraunhofer Institut in Stuttgart confirmed very low noise levels during sewage flow.

Chemical and thermal resistance

The internal surface shows high chemical resistance to domestic sewage in the pH range from pH 2 to pH 12 at temperatures up to 50°C (for continuous domestic applications). The system maintains dimensional stability due to a low thermal expansion of only 0.0105 mm/mK - comparable to concrete.

The thermal conductivity coefficient is 50-60 W/mK at a temperature of 20°C. The component can be used in external installations due to its high resistance to mechanical and chemical conditions.

Installation, compatibility, and certificates

The coupling-free design allows for quick installation without the use of special tools - the elements are connected using appropriate pipe clamps (clamps, bands, or couplings). The system allows for easy adaptation to pipes with a nominal internal diameter of 80 mm (the external diameter is standard for the SML system).

The bend is used to change the direction of sewerage pipes and drainage installations at a right angle (88°). It ensures the stability and tightness of connections as well as resistance to mechanical damage during operation.

The product meets the requirements of EN-877 and RAL-GZ 698 (a German quality standard with a significantly expanded scope of control). It bears the CE marking confirming the declaration of conformity according to EU directives for construction products (89/106/EWG).

The system is covered by a liability assumption agreement concluded between PREIS & CO and ZVSHK (the Central Association of the Sanitary, Heating, and Air Conditioning Industry), which guarantees extended liability up to a maximum sum of 1.2 million euros per event in case of damage or secondary damage.

The component is fully recyclable - production is based mainly on recycling iron from scrap metal without wasting natural resources.