Question 1

Can alpex pipe connections be used for concealed installations or under screed?

Accepted Answer

The alpex pipe and system connections for drinking water and heating installations are suited for concealed installations or installations under screed without any concerns. For detailed information, please refer to DIN 1988 / DIN EN 806.

Question 2

Is it necessary to insulate alpex multilayer composite pipes for cold water lines against condensation water?

Accepted Answer

Yes, insulation of cold drinking water pipes is required according to DIN 1988-200 tab. 8 and 9 in order to prevent condensation and to protect drinking water from warming-up due to elevated ambient temperatures. Pipes that come into contact with the structure (floating, screed, etc.) must be protected with at least one layer of insulation (pipe with protective sheathing). Sound insulation according to DIN 4109 must be provided. Appropriate insulation is recommended for prevention of cracking and flow noise.

Question 3

Are alpex installations possible with de-mineralised water?

Accepted Answer

No, since the installation of multilayer composite pipe systems usually includes brass fittings. Brass fittings may be affected by corrosion damage in connection with de-mineralised water (aggressive).

Question 4

Are alpex installations possible with softened water?

Accepted Answer

Yes, alpex installations (pipe + PPSU + brass) can be operated with softened water of up to 0°dH. The limit value for sodium ions of 200 mg/l may not be exceeded during softening. For reasons of corrosion protection, it is recommend that the water hardness level should be of at least 3°dH. If drinking water is intended for human consumption, water hardness of 4 to 8°dH is ideal.

Question 5

Can I use antifreeze agents with alpex multilayer composite pipes?

Accepted Answer

The alpex multilayer composite pipes can be used with antifreeze agents at temperatures between -20 °C and +95 °C (max. permissible continuous operating temperature) and a maximum constant operating pressure of 10 bar. However, make sure that the antifreeze agent used has no impact on polyethylene, EPDM, PPSU and brass. For reasons of corrosion protection, minimum concentration shall not fall below 25 % vol.

Question 6

Can I use alpex multilayer composite pipe systems in stables?

Accepted Answer

The alpex multilayer composite pipe system is limitedly resistant to ammonia content in the atmosphere that often occurs in stables. Corresponding alpex fittings and connectors, however, are exposed to a high risk of corrosion under these conditions. The installation should therefore be of concealed type. If it is not possible, fittings and connectors must be protected by means of appropriate measures such as wrapping in a corrosion protection tape (e.g. DENSO tape, KEBU tape) or a vapour-tight insulation (e.g. Armaflex). We recommend that the alpex system should be protected with a vapour-tight insulation.

Question 7

Are alpex multilayer composite pipes free from plasticisers and CFC?

Accepted Answer

Yes, alpex composite pipes are free from plasticisers and CFC, since pure polyethylene (PE) is used as a material during production. Thus, there are no materials that emit gases as is the case with e.g. PVC.

Question 8

How do I pressure test drinking water installations with alpex?

Accepted Answer

Pressure testing must be carried out according to DIN EN 806-4 and the ZVSHK advisory leaflet "Leak Testing of Drinking Water Installations" (Dichtprüfungen von Trinkwasserinstallationen). Detailed requirements of pressure testing must be complied with depending on the test medium (water or air); please refer to pressure test reports water / air available in the download centre.

Question 9

What applications can I use alpex multilayer composite pipes for?

Accepted Answer

The alpex multilayer composite pipes can be used for various media, such as drinking water, heating, stormwater and compressed air. Please refer to the alpex Technical information for more details.

Question 10

Up to which max. heat capacity can I connect alpex pipes?

Accepted Answer

Please refer to the Technical information for detailed alpex performance and pressure loss tables for heating applications. We recommend that the following standard flow values are not exceeded when designing the pipework system:
Radiator connection pipe ≤ 0.3 m/s
Radiator distribution pipes ≤ 0.5 m/s
Heating riser and basement pipes ≤ 1.0 m/s
The max. pressure loss in the pipe must not exceed 2 mbar/m.

Question 11

Who designs and implements my drinking water installations?

Accepted Answer

Professional design and hygienically impeccable installation must be made by experts only, otherwise any warranty claims become void. Additionally, health and safety risks during operation may be the consequence. Drinking water pipes must therefore be installed with expert knowledge and tested carefully and thoroughly before putting into operation.

Question 12

Are the materials used in my drinking water installation safe to use?

Accepted Answer

The materials used in alpex multilayer composite pipe systems meet highest requirements for drinking water installations and have been certified and approved according to DVGW. Both the alpex composite pipe designs with internally cross-linked PE-X materials and a butt-welded aluminium core (PE-X / AL / PE) as well as the corresponding fittings made of PPSU or dezincification-resistant brass for threads are physiologically safe and of food quality, i.e. the material has no adverse effects on the human body. Hygiene and microbiological testing is an integral part of the DVGW type approval certificate and is particularly stringent with plastic pipe systems. The materials applied comply with the currently valid list of approved materials of the German Environment Agency (UBA) and the Drinking Water Ordinance.

Question 13

How can I avoid legionella development in drinking water?

Accepted Answer

At water temperatures between 25 and 55 degrees, legionella and bacteria can multiply and occur in increased concentrations. These die off again at water temperatures above 70 degrees. For this reason, the temperature of warm water in the pipe system shall be at least 55 degrees, and that of cold water shall not exceed 25 degrees. Along with the temperature, stagnating water also favours bacteria proliferation; therefore, permanent flow of water through the drinking water installation shall be ensured. Avoid dead pipes and water stagnation. Regular water exchange at tapping points shall be executed every 72 hours at the latest. Regular water exchange after 7 days at the latest is part of proper and intended operation of a drinking water installation.

Your web browser is outdated.