Knee press 90° - PPSU, 40 x 40

Product detailed description

This 90° press elbow is commonly used in residential and commercial heating and plumbing installations where a directional change in piping is required. It is typically found in underfloor heating systems, domestic hot water circuits, and central heating applications. Installers and technicians working with ALPEX press systems will find this fitting essential for creating accurate, leak-free bends in the piping layout. The elbow is designed to maintain system integrity under standard operating conditions and is suitable for use in both new builds and retrofit projects.

Its compact dimensions and compatibility with standard press tools make it ideal for tight spaces and high-volume installations. The PPSU material ensures resistance to thermal stress and chemical exposure, while the stainless steel ferrule and EPDM seal provide reliable sealing performance. This fitting is particularly suited for systems where long-term durability and minimal maintenance are required.

Technical parameters

Installation and connection

Installation involves cutting the ALPEX pipe to the required length and inserting it into the fitting until it reaches the stop mark. The press pliers must be aligned with the fitting and applied with the correct force to compress the ferrule around the pipe. The connection size is 40 x 40, indicating equal-diameter connections. Installers should verify that the pipe is fully inserted and that the pliers are correctly positioned to avoid misalignment or incomplete compression. Common mistakes include using incorrect plier types or applying uneven pressure, which can compromise the seal and lead to leaks.

Compatibility and accessories

This 90° press elbow is specifically designed for ALPEX press systems and must be used with compatible stainless steel ferrules and EPDM seals. It is compatible with B-F-TH type pliers for pressing. No additional products are required for standard installation, but installers should ensure that all components are from the same system to maintain compatibility and performance. This fitting is not interchangeable with other press systems or mechanical compression fittings.

Technical background for designers

The operating principle of this press elbow relies on the deformation of the stainless steel ferrule around the ALPEX pipe during pressing, creating a metal-to-plastic seal. The PPSU material offers high thermal stability and resistance to creep under sustained loads, making it suitable for long-term operation in heating systems. The EPDM sealing ring ensures a tight fit and prevents fluid leakage. Designers should consider the thermal expansion characteristics of the system and ensure that the fitting is integrated in a way that minimises stress on the joints. The service life and efficiency of the fitting are influenced by correct installation, system pressure, and operating temperature.

Service and operation

Once installed, this press elbow requires no regular maintenance and is designed for a long service life. However, installers should periodically inspect the joint for signs of leakage or mechanical stress, particularly in areas with high vibration or thermal cycling. If a leak is detected, the fitting must be replaced as re-pressing is not recommended. There are no scheduled service intervals specified for this component, and it is intended for permanent installation.

Frequently asked questions

Can this press elbow be used with other pipe materials besides ALPEX?
No, this fitting is specifically designed for ALPEX press systems and is not compatible with other pipe types or press systems.

Is it possible to re-press the fitting if the initial press is not successful?
No, the fitting is not designed for re-pressing. A new fitting must be installed if the initial press is incorrect or incomplete.

What type of pliers are required for installation?
This fitting is compatible with B-F-TH type pliers. Using other plier types may result in an improper connection.

Can this fitting be used in systems with higher pressure than PN 10?
No, the nominal pressure rating of PN 10 must not be exceeded. Exceeding this pressure may compromise the integrity of the fitting and the system.