G-ITALY aluminium flanges

Loose aluminum flanges, for pressure till 10/16 bar, are a very interesting alternative to those made in other materials, thanks to the following characteristics, which are at the same time present in the aluminium:

LIGHTNESS

GOOD RESISTANCE TO CORROSION

HARDINESS

CHEAPNESS

ISO-METRIC TYPE

Loose aluminium flanges for pipes with collars. Dimension compatible with EN 1092-1/02 PN 10 and, until DN150, PN16 standards. Inside diameter fit for ISO and metric pipes with thickness from 1 to 3 mm.

TP-TYPE (for PE/PVC pipes)

Loose aluminium flanges for PE/PVC pipes with collars.
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LITE TP-TYPE

Lap-joint aluminium flanges for collars. Dimensions compatible with EN 1092-1 PN10/16 standards. Inside diameter fit for plastic (PE) pipes.
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LITE TYPE ISO-METRIC

Loose aluminium flanges for pipes with collars. Dimensions compatible with EN 1092-1/02 PN10 and, up to DN150, PN16 standards. Inside diameter fit for pipes according to ISO or metric standards.

FF-ANSI 150 TYPE

Loose (lap joint) aluminium flanges for pipes with collars. Dimensions compatible with EN1759-4 Class 150. Inside diameter fit for pipes according to ISO standards.

PN6 TYPE

Loose aluminium flanges for pipes with collars. Dimensions compatible with EN 1092-1/02 PN6 standards.
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BLIND TYPE

Blind aluminium flanges. Dimensions compatible with EN 1092-1/05 PN10 standards.
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BLIND PN16 TYPE

Blind aluminium flanges. Dimensions compatibles with standards UNI 6093 PN16.
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FF-BG PN10 TYPE

Threaded aluminium flanges. Dimensions compatible with EN 1092-1 PN10/16 standards. Inside diameter threaded acccording to ISO 228/1 or NPT ac- cording to ANSI/ASME B1.20.1.

FF-G PN10 TYPE

Threaded aluminium flanges. Dimensions compatible with standards EN 1092-1 PN10/16 Inside diameter threaded acccording to UNI ISO 228/1.
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PRESSED TYPE

Pressed flanges. Dimensions compatible with standards EN 1092-1/02 - DIN 2642
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Upon request we can produce special flanges.



Why choose aluminium?

Lightness

Being less heavy (over30%) than steel, aluminium is more functional in installation, maintenance, loading, unloading, storage and transport.

High corrosion resistance

In most cases the physical and chemical characteristics of aluminium allow the use of these flanges without any surface preservative treatement. Optionally you can cover the flanges with a  coat of epoxy paint.

Robusteness

Relied by technical proofs of resistance and by years of usage of this metal.


Technical information

FLANGES - GENERALITIES

The use of the flanges, as component of pipes joint, is generally necessary for the assembly and disassembly of equipment or pipes parts.

LOOSE FLANGES

The loose flanges are slipped on the pipe and lean against a ring or a collar welded at pipe, which is the only part of joint that comes in contact with the fluid. Their use appears economic for aggressive fluids which need pipes in expensive materials (stainless steel, etc.) as the flanges can be in less valuable material, like aluminium, carbon steel or other.

LOOSE ALUMINIUM FLANGES

Loose aluminium flanges offer the following advantages:

  • Lightness: the aluminium (specific gravity 2.7) is about 3 times less heavy than steel, with resulting notable facilities in installations, maintenance, generic handling (loading, unloading, storage, etc.) and carriage charges.
  • Good resistance to corrosion: the physical-chemical properties of aluminium allow, in most cases, the use of flanges in this material, without any protective surface treatment, showing no appreciable phenomenon of corrosion.
  • Strength: our aluminium flanges are strong enough, as per specific tests and the practical use during many years.

Information concerning aluminium

The flanges are aluminium allo die-casted and present EN AC-47000 Al Si 12(Cu) discrete mechanical properties and sufficient corrosion resistance.

Mechanical properties at room temperature are as follows (UNI EN 1706:2010) part 3 table 7.1:

Tensile strength 170 N/mm2
Feld strength 90 N/mm2
Brinell hardness 55 HB
Elongation  2%

EXCELLENT CORROSION RESISTANCE

Usually the aluminium flanges are supplied with blank surfaces and, without any treatment, are installed on stainless steel or aluminium or plastic pipes as, in normal atmosphere, the natural film of aluminium oxide (Al2O3) that forms on the flange surface shows a sufficient resistance to corrosion.

In humid atmosphere it forms a thick layer of oxide whose outside is porous and hydrates with small particles or white deposits, while the side adherent to the surface is a continuous porous film durable and insoluble in 4.5 to 8 ph field.

This natural passivation allows, in most cases, to use aluminium flanges with blank surfaces. On the surface of contact between stainless steel and aluminium is not produced any phenomenon of corrosion for contact.

SIZING OF THE FLANGES 

Our aluminium flanges follows the dimensions according to the UNI EN 1092-1:2013 PN10, PN16, EN1759-4 Class 150 (ANSI TYPE) and DIN 16963 (TP-TYPE) regarding both the outer diameter of the flanges and the interaxis space number of the holes for the bolts. These dimensions apply with the UNI 2223-67 6092-67, DIN 2501 and DIN 2527 norms.

Thickness: over ND 25 up to ND 250 according to UNI 6089 (DIN 2642) standards, over ND 250 see the dimensional tables. For the thickness of the TP-TYPE flanges (strengthened and reg. form) see the relative dimensional tables.

Tests carried out from official corporations at our factory attest, for flanges of our production (ISO and METRIC flanges up to DN 500 and LITE flanges) the tightness up to 10 or 16 bar and various tests from our quality service attest the tightness of TP-TYPE flanges (hydrostatic test up to ND 300).
As information from DN 500 the maximum allowable pressure changes from 6 to 4 bar.

The practical use of millions of gea flanges for several years and a business system of production technology certified by the prestigious ISO 9001:2015 demostrate that our aluminium flanges afford an absolutely reliability.

RESISTANCE TO TEMPERATURE/THERMAL CONDUCTIVITY 

THERMAL  CONDUCTIVITY AT 20°C EN-47000 → 130 - 150 W/(mK).

The resistance of the aluminium alloy to various temperatures is the following:

Temperature from -250°C
up to 50°C
100 °C 150 °C
Tensile strength N/mm2 170 150 120

On this matter we can note that the temperature of the aluminium flanges is always very lower than the one of the pipes because there is a rapid dispersion of the absorbed heat as the capacity of heat conduction of aluminium is 3 times better than carbon steel alloys and 6 times than stainless steels.

G-ITALY flanges prooved a rapid, previously absorbed,  heat loss.

COATED FLANGES

When flanges are installed in very humid places, in grounds or when the white oxides must be excluded for aesthetics reasons, are used flanges covered by an enamel composed of powders that has high mechanical resistances and good chemical resistances.

First the surface of the flange is prepared with a mechanical (sand-blasting) or chemical treatment to guarantee the maximum adhesion of the covering thick and the best resistance to corrosion.

Powders are so applied in electrostatics way and, after baking in the furnace, form a very adherent and resistant film, but sufficiently elastic as to follow the thermic dilatations of the flange.

We report here below, only like information title, the characteristics of the covering concerning the standard tests for applications on laminations treated with phosphates.

Type of coating EPOXI-POLYESTER
Composition Epoxi-polyester powders
Mechanical properties of the coating
Thickness (ISO 2360) 60 micron
Adherence (ISO 2409) GT 0
Hardness (EN ISO 2815) H - 2H
Collision Resistance (ECCA T8) > 2,5 Nm
Shaping (ISO 1520) > 3 mm
Bending (ISO 1519) 5 mm
Brightness 80 - 90 glos
Resistance to corrosion
Saline fog (ASTM B117) 500 hours (1 mm. of penetration on the cross)
Humidity resistance (IUNI 8744) 500 hours: no change
 Demineralized water (ASTM D870) 500 hours: no change
Resistance to solvents
Ethyl alcohol - Buthyl alcoh No softening
Toluene - Xylene Light softening
Trichloroetane - Perchloroetane Hard softening
Methylethylketone - Acetone Hard softening
Gasoline  No softening

- Temperature of use: from -25°C to 50°C
- Standard colour: RAL 7031