De Marinis ISO 25 PLUS P2T3 330 mm insulated twin-wall flue pipe

The De Marinis P2T3 is the 330 mm nominal length straight section of the ISO 25 PLUS insulated twin-wall flue system, designed for professional indoor and outdoor installations.

It features an AISI 316L BA stainless-steel inner wall, an AISI 304 BA stainless-steel outer wall and 25 mm blown mineral wool insulation.

A key feature of ISO 25 PLUS is its G50 classification for high-temperature applications. When installed in the certified De Marinis configuration, the system is classified for a 50 mm distance from combustible materials.

The P2T3 is available in nominal internal diameters from Ø80 to Ø350 mm.

Main features

• Manufacturer: De Marinis
• Range: ISO 25 PLUS
• Product family: P2T3
• Type: insulated twin-wall straight flue pipe
• Nominal length: 330 mm
• Usable height Hu: 275 mm
• Joint depth I: 45 mm
• 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
• Installation: indoor or outdoor
• Available internal diameters: Ø80, 100, 130, 150, 180, 200, 250, 300 and 350 mm

330 mm straight flue section

The P2T3 provides a 330 mm nominal straight section for modular ISO 25 PLUS flue systems.

It is particularly useful where the system layout requires more precise adjustment than can be achieved using only 1000 mm or 500 mm sections.

De Marinis specifies a usable height of Hu = 275 mm and a joint depth of I = 45 mm.

ISO 25 PLUS and G50 classification

For high-temperature operation ISO 25 PLUS carries the designation:

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

The G50 classification corresponds to a 50 mm distance from combustible materials when installed in the certified configuration.

Important: G50 applies only to the certified ISO 25 PLUS configuration installed according to De Marinis instructions.

25 mm insulated twin-wall construction

The P2T3 consists of two concentric stainless-steel walls separated by 25 mm blown high-density mineral wool insulation.

The inner wall is manufactured from AISI 316L BA stainless steel, while the outer wall is manufactured from AISI 304 BA stainless steel.

The construction is designed to reduce thermal bridging between the inner and outer walls.

Applications

ISO 25 PLUS is designed for modular metal flue systems serving applications including:

• conventional boilers;
• atmospheric appliances;
• pressurised generators;
• forced-draught generators;
• condensing boilers;
• wood-burning stoves;
• fireplaces;
• pellet stoves;
• domestic and industrial kitchen extraction hoods;
• compatible air exhaust applications.

CE marking and designations

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

P2T3 dimensions and De Marinis product codes

Dimensional note: nominal commercial length is 330 mm. De Marinis specifies Hu = 275 mm and joint depth I = 45 mm for all P2T3 variants.

How to read the technical dimensions

• Øi: nominal internal flue diameter;
• Øe: external diameter of the insulated twin-wall pipe;
• Hu: usable height, 275 mm;
• I: joint depth, 45 mm;
• 25 mm: insulation thickness.

Jointing and installation

ISO 25 PLUS elements use a calibrated male/female socket joint and are mechanically secured using the appropriate locking band.

Where required by the certified configuration, a triple-lip elastomeric gasket compliant with EN 14241-1 is fitted to the inner wall.

T200 and T600 configurations

• T200 / P1: wet and positive-pressure operation using the sealing gasket specified for the system;
• T600 / N1: high-temperature negative-pressure operation without the elastomeric sealing gasket, according to De Marinis instructions.

Installation and safety

Flue diameter, system configuration, support arrangement and combustible-material clearances must be determined according to the appliance and system design.

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