GM-X Galvanized Pipes

Introduction / Material properties

Drain pipes and fittings are manufactured from welded, one-time cold-drawn precision steel pipe in accordance with DIN 2394. As a material, steel is practical properties:

  • unbreakable
  • dimensionally stable
  • heat and frost proof
  • favourable acoustic behaviour
  • non-combustible

Tensile strength:
Rm 310-410 N/mm2

Elongation at break:
A5 min. 28%

Thermal expansion

Steel’s thermal expansion is exceptionally low. When a 1 metre piece of pipe is heated by 100°C, the length increase is 1.1 mm. The thermal expansion produced by the introduction of hot wastewater does not therefore need to be considered in the installation.

This does not apply to other standard materials.

Acoustic behaviour

Sound measurements for discharge noise in built-in drain pipes produced results within the requirements of DIN 4109. The measured noise figure was below the permissible sound level. To further decrease discharge noise, and as an additional sound-proofing measure, rubber in-fills are fitted to the support brackets.

GM-X Socket/Seal/Tightness

The GM-X socket is a two-stage design. The seal is retained in the first stage of the second while the second stage centres the inserted pipe.  The socket shape design enables solid, buckle-proof and rigid connection of pipes. Joint tightness is guaranteed between the pipe and the socket, without the risk of the seal being compressed by its own, or an outside load.

The GM-X seal is in the shape of a lip collar. It is inserted into the upper, first stage, socket chamber. When a pipe end is inserted, the sealing lips are forced against the inner wall of the seal housing and against the outer wall of the inserted pipe. The seal collar is located on the socket rim and ensures the seating of the seal when the pipe is pushed in. The sealing lips press more firmly against the pipe walls as fluid pressure rises, thus positively increasing the tightness of the joint.

The seal is manufactured as standard from an effluent-resistant grade (as per DIN 4060):

  • NBR (Nitrile Butadiene Rubber)
  • SBR (Styrene Butadiene Rubber)

For special use areas seals can be supplied in the following grades on request:

  • CR (Neoprene)
  • Si (Silicon)
  • FKM (Viton)

The socket seal-tight connection value requirements in DIN EN 1123 are achieved by ACO GM-X. All pipes and
fittings, including their joints, are tight at an inside and outside pressure above atmospheric of 0 to 0.5 bar. For pipe lines with higher pressures, the GM-X securing clip can be used for extra security against axial thrust. Instead of the securing clip, GM-X securing clamps are supplied for DN 150 and DN 200 pipes and fittings for axial stability. The following seal-tight values were determined for GM-X seal joints with securing clips and glued-on seals:

  Operation pressure  
DN 40 15 bar
DN 50 15 bar
DN 70 5 bar
DN 80 5 bar
DN 100 5 bar
DN 125 4 bar
DN 150 2 bar
DN 200 1 bar

Vacuum installations/seal

The vacuum installation with x-socket and GM-X-VACplus sealing element, corresponds to installations of the standard GM-X sealing element. In contrast to the aforementioned installation the GM-X-VACplus sealing element fills both socket stages. Therefore guaranteeing a trouble-free vacuum operation. The seal-tight value of the vacuum seal joint complies with DIN 86 281.

The GM-X-VACplus sealing element allows vacuum installations with “standard socket Type A1”. The GM-X-VACplus seal is in the shape of a lip collar. As result of the other pipe end being pushed in, the sealing lips are forced against the inner wall of the seal housing and against the outer wall of the inserted pipe.

Deck and bulkhead penetrations with fitted flange

Parts of the flange are not hot galvanised and therefore allow for welding in decks and bulkheads.

In accordance with:

  • DIN 86280
  • DIN EN ISO 15749
  • DIN 86287
  • DIN 86288
  • DIN EN 1123

Deck and bulkhead penetrations with thick walled pipe

The welded body is not hot galvanized, so that it can be welded in decks and bulkheads.

In accordance to:

  • DIN 86280
  • DIN EN ISO 15749
  • DIN 86287
  • DIN 86288
  • DIN EN 1123

Corrosion proofing / Installation

All pipes and fittings are hot galvanised inside and out. The zinc coating is on average 400 g/m2 or 56 μ. It is impact-resistant and shock-proof. The zinc coating produces a cathodic protection of the cut edges thus preventing edge corrosion. In addition, the insides of the pipes and fittings are given an alkyd-melamine resin based plastic coating. Due to this internal coating of the pipes, frictional resistance on the internal surfaces is reduced and incrustation largely prevented. Together with the zinc coating, optimum corrosion protection is achieved. Both the hot galvanizing and the additional internal coating meet the requirements of DIN EN 1123.


The onus is on the installer, who, in the final analysis, determines the practical value of a drainage installation. The superior quality of our pipe material and the first-class processing of our products help him in this task.

Drainage installations have to be able to be constructed without problems and work without any malfunction. Any connection problem can be quickly and economically resolved by the availability of an extensive range of fittings.

The extensively developed socket joint enables rapid and simple plug-in assembly, just by turning the pipe and the fitting in the socket. Steel pipes and fittings are easy to handle, impact-resistant and shock-proof, and unaffected by rough treatment during installation. The GM-X push-fit pipe range can also be supplied with double sockets, one at each end. When a pipe is cut to size, there is a piece left over with a socket, which can be used as an extra fitting piece. Steel drain pipes and fittings – together with the characteristic plug-in socket joint – give the installed drain pipe a practically self-supporting stability. The use of pipe clips and holding devices is only necessary at critical locations in the installation.

Cutting to length can be carried out by pipe cutter, a cutting wheel or a saw. Pipes cut to length with a wheel or saw must be de-burred before being inserted in the socket so as not to damage the seal during installation.

Production monitoring/QM/Certification
Production monitoring

GM-X drain pipes and fittings are subject to production monitoring by a certified institute. GM-X seals are also subject to production monitoring by a certified institute.

Quality management

GM-X drain pipes and fittings are subject to production in accordance to EN ISO 9001:2009.


The ACO Marine GM-X push-fit pipe system meets all the requirements of both the ship and offshore building industries and is recognised and certified by all leading maritime classification societies and affirms their high operational safety.