Knee press 90° - PPSU, 50 x 50

Product detailed description

Press elbows are essential components in closed-loop water circuits in residential and commercial buildings. They enable directional changes in piping while maintaining hydraulic integrity. Installers working on underfloor heating, central heating or hot water distribution systems commonly use these fittings. Proper installation ensures leak-free operation and long-term system reliability.

These fittings are often found in concealed installations such as wall cavities, floor slabs or ceiling spaces. They are frequently used in conjunction with other press fittings such as straight couplings, tees and adapters. The PPSU material provides chemical resistance and dimensional stability under thermal cycling.

Technical parameters

Installation and connection

The press elbow is installed using a compatible press tool with B-F-TH jaw type. The ALPEX pipe is inserted into the fitting until it reaches the stop mark. The tool then applies radial force to compress the stainless steel sleeve around the pipe. The EPDM sealing ring ensures tightness. Connection sizes must match the pipe outer diameter precisely. Common installation errors include insufficient insertion depth, misalignment during pressing and using incompatible jaw types.

Installers should verify the pipe cut quality, absence of burrs and correct positioning before pressing. After installation, the fitting should be visually inspected for even compression marks and proper seating. Any deformation or uneven pressing should be corrected immediately.

Compatibility and accessories

This press elbow is specifically designed for ALPEX pipes of the same diameter. It requires a stainless steel sleeve and EPDM sealing ring, which are integrated into the fitting. The fitting is compatible with press tools featuring B-F-TH jaws. For large-scale projects, it is recommended to order sufficient quantities of sleeves and sealing rings as spare parts.

Technical background for designers

The press connection operates by mechanically deforming the stainless steel sleeve to create a metal-to-plastic bond. The PPSU material offers high heat resistance and creep strength, ensuring dimensional stability under prolonged thermal loads. The EPDM sealing ring compensates for minor tolerances and provides additional tightness. The system's longevity depends on correct installation, material compatibility and thermal expansion management in the piping layout.

Designers should account for thermal expansion in the system layout and ensure adequate support for press fittings. The nominal pressure and temperature ratings must align with the system's operational requirements. The fitting integrates seamlessly into press-fitting-based systems using ALPEX piping.

Service and operation

No routine maintenance is required for this fitting once correctly installed. Visual inspections during system maintenance can confirm the integrity of the press marks and absence of corrosion or deformation. In case of suspected leaks, the entire press connection should be re-pressed using the correct tool and jaw type.

Frequently asked questions

Can this press elbow be used with other pipe types?
No, it is specifically designed for ALPEX pipes. Using it with other materials may compromise the seal and structural integrity.

Is this fitting suitable for hot water systems?
Yes, the operating temperature limit of +120 °C makes it appropriate for hot water and heating systems.

Can the press elbow be reused after removal?
No, the stainless steel sleeve is deformed during pressing and cannot be reused. A new fitting must be installed.

What press tool is required for installation?
A press tool equipped with B-F-TH jaws is required for correct installation and sealing.