Geberit Mapress stainless steel transition coupling with female thread: d=18mm, Rp=3/4'' 31804

Press connection system for sanitary installations

The Geberit Mapress Edelstahl transition coupling is an element of a piping system based on press connection technology. The design of this type of coupling allows for fast and secure installation without the need for welding or brazing - appropriate M-profile pressing jaws are sufficient to press the sleeve onto the pipe and create a durable, leak-proof connection.

Construction and materials

The coupling body is made of stainless steel grade 1.4401 (AISI 316) - a chromium-nickel-molybdenum alloy resistant to drinking water corrosion and industrial conditions. The wall thickness at the connection is 1 mm, which ensures high mechanical strength while maintaining compact dimensions.

On the pipe side, there is a press sleeve with an outer diameter of 18 mm (DN 15), adapted for use with M-profile jaws. The working length of this connection is 1.5 mm, and the total length of the connection part is 20 mm. The opposite side features a cylindrical internal thread Rp 3/4" according to the BSPT-Rp (ISO 7-1 / EN 10226-1) standard, also made of stainless steel - with a working length of 18 mm.

An important structural element is the CIIR seal (chloroprene rubber) seated in the sleeve socket. This material withstands contact with drinking water, acidic environments, and temperatures up to 120°C, allowing for use in central heating installations and district heating networks.

The coupling is equipped with a press indicator - a characteristic protrusion or groove visible before pressing, which disappears after a correctly executed connection. This is an intuitive form of installation quality control on the construction site. Additionally, the sleeve is equipped with a transparent plastic protective cap, which protects the interior of the element from contamination during transport and storage.

Application and compatibility

The Geberit Mapress system is suitable for domestic, industrial, and marine installations. This specific coupling, thanks to the combination of the 18 mm press sleeve and the Rp 3/4" internal thread, is used to create transitions between steel piping and threaded fittings - such as valves, filters, or outlets.

The range of media permeable through the system includes:

• drinking water (cold and hot),
• water for cooling and heating purposes,
• district heating water up to 120°C,
• saturated steam up to 120°C,
• process and treated water,
• rainwater with pH > 6.0,
• grey and black water with pH > 6.0,
• water for sprinkler and fire extinguishing systems,
• compressed air of oil cleanliness class 0-3,
• inert gases (e.g., nitrogen) and industrial gases,
• selected chemicals and technical fluids.

The Rp 3/4" thread corresponds to a nominal diameter of DN 20 - typically found in domestic connections for bathtub or washbasin mixers.

Operational properties

Press connection technology offers several significant practical benefits. Firstly - the absence of open flames or high temperatures during installation eliminates the risk of fire and damage to surrounding materials. Secondly - a connection made with electric or cordless pressing tools takes literally seconds, significantly accelerating installation work even with a large number of points.

A key feature of the system is the "unpressed, leaking" principle - meaning "unpressed, leaking." If the installer forgets or incorrectly performs a connection, the element will leak during the initial pressure test of the installation. It cannot be installed "dry" thinking it will somehow be tight - which enforces diligence and simultaneously protects against hidden defects.

Due to its high tensile strength, the press connection meets the requirements of standards for gas and sprinklerinstallations, where resistance to axial forces acting on the pipeline is required.

The total length of the coupling is 38 mm, the Z dimension (axial offset) is only 0.3 cm, so the element does not disturb the geometry of the pipeline route - making it suitable for installation in built-in structures or in limited ceiling spaces.