De Marinis ISO 25 PLUS P2T4 45° tee branch G50

The De Marinis P2T4 45° tee branch is a component of the ISO 25 PLUS G50 insulated twin-wall flue system, designed to create a 45° inclined branch connection to the main chimney.

Its inclined geometry provides a more gradual change in flue-gas direction than a conventional 90° tee, helping reduce local turbulence and pressure losses.

The P2T4 follows the ISO 25 PLUS construction, with an AISI 316L BA stainless-steel inner wall, an AISI 304 BA stainless-steel outer wall and 25 mm blown mineral wool insulation.

It is available in nominal internal diameters Ø80, 100, 130, 150, 180, 200, 250, 300 and 350 mm.

Main features

• Manufacturer: De Marinis
• Range: ISO 25 PLUS G50
• Product family: P2T4
• Type: 45° tee / branch fitting
• Branch angle: 45°
• Function: inclined connection between branch and main flue
• Inner wall: AISI 316L BA stainless steel – EN 1.4404
• Outer wall: AISI 304 BA stainless steel – EN 1.4301
• Insulation: 25 mm blown mineral wool
• System: insulated twin wall
• Installation: indoor or outdoor
• Available internal diameters: Ø80 to Ø350 mm

What the P2T4 is used for

The P2T4 is designed to connect a secondary flue section to the main chimney at a 45° angle.

Typical applications include connections between an appliance flue pipe and the vertical chimney or other branch arrangements specified by the flue design.

Advantages of a 45° branch

The inclined branch allows combustion gases to enter the main flue through a more gradual change of direction.

Compared with a perpendicular 90° connection, this geometry can help:

• reduce local turbulence;
• limit pressure losses;
• provide a smoother flue-gas path;
• simplify certain appliance-to-chimney layouts.

The correct fitting must always be selected according to the appliance, flue design and applicable regulations.

ISO 25 PLUS and G50 classification

The P2T4 belongs to the De Marinis ISO 25 PLUS insulated twin-wall flue system.

Its high-temperature system designation is:

T600-N1-W-V2-L50040/050/060-G50

The G50 classification corresponds to a 50 mm clearance from combustible materials when the system is installed in the certified De Marinis configuration.

Important: G50 is a classification of the complete certified ISO 25 PLUS system. It should not be interpreted as an independent clearance rating of the P2T4 fitting alone.

ISO 25 PLUS construction

• Inner wall: AISI 316L BA stainless steel;
• Outer wall: AISI 304 BA stainless steel;
• Insulation: 25 mm mineral wool;
• Configuration: insulated twin wall;
• Installation: indoor or outdoor.

CE marking and system designations

The ISO 25 PLUS system is CE marked according to EN 1856-1:2009.

P2T4 dimensions and De Marinis product codes

Dimensional note: A and B vary according to the nominal diameter and represent the principal overall dimensions of the 45° branch fitting. Refer to the De Marinis technical drawing when planning installation clearances.

How to read the technical drawing

• Øi: nominal internal flue diameter;
• Øe: external diameter of the insulated twin-wall system;
• A: main overall fitting dimension;
• B: secondary overall fitting dimension;
• 45°: branch angle relative to the main flue axis.

Installation

The P2T4 must be installed according to the required flue-gas flow direction and system layout.

The fitting and connected sections must be properly supported so that structural loads are not transferred incorrectly to the branch.

The installation should also allow adequate access for inspection, cleaning and maintenance.

Installation must be carried out by qualified personnel in accordance with De Marinis technical documentation, appliance instructions and applicable regulations.