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Every project is unique - and that also applies to the projects we are allowed to accompany.

And yet: Some questions have been asked more often than others in the past. So that you don't have to wait for our answers, we have collected the most frequently asked questions here - together with our answers, of course. These are the aquatherm FAQ.

Material properties

Material properties

The thermal expansion for faser (MF) pipe is approximately double that of copper or steel, whereas other plastics, or PP without the faser layer, can be as much as 5 to 10 times that of copper or steel. So, while the faser layer does not reduce the expansion to be equal to metal pipe, it is much closer and as a result will require much less expansion compensation (e.g. loops, offsets, expansion joints, etc).

The Hazen-Williams coefficient for polypropylene pipe is 150. This coefficient is used with the Hazen-Williams equation for friction loss calculation in pipes. The higher the factor, the lower amount of friction loss there will be in the pipe system. In most cases Aquatherm pipe has a higher Hazen-Williams coefficient than metal pipe when installed, and this factor won’t decrease over the lifetime of the system as it does with metal piping.

The pipe is suitable for industrial vacuum lines (29.9 inches Hg or 760 mm Hg), but is not intended for ultra-high vacuum.

aquatherm pipes and fittings are made entirely from the Fusiolen resin. Fusiolen is 97% pure polypropylene random, with the remaining 3% being a PP-R masterbatch which includes color pigments and stabilizers.

Polypropylene is non-reactive with many chemicals, but chemical compatibility also depends on concentration and temperature. There is a chemical resistance guide available on which includes many, but certainly not all chemicals. The easiest way to find out if Aquatherm pipe is suitable for use with a certain chemical is to submit a chemical inquiry form either online or by email. Aquatherm can confirm compatibility and return a written verification usually within 24-48 hours.

Working pressures and temperatures for aquatherm pipes can be found in the our technical catalogues.

Polypropylene will not corrode and is not affected by scaling, the way many other materials are. It also does not support microbiological growth. 

aquatherm pipes are much quieter than metal pipe and tend to dampen sounds rather than carry them. The wall thickness of the pipe and fittings are heavier than most other plastic piping, and the material modulus is substantially less than metal, thereby reducing the sound transmission when compared to other plastic and metal piping.

aquatherm pipe with multi-layer, faser-composite has its linear expansion reduced by at least 75% when compared to standard polypropylene and other plastic piping materials. Detailed charts can be found in the aquatherm technical catalogues.

aquatherm piping is considered to be freeze‐tolerant, meaning that it normally will not rupture if accidentally allowed to freeze provided the pipe can expand with the freezing water.

However, it is also not intended to be installed in a location where it would be subjected to repeated freeze/thaw cycles. Antifreeze measures should be taken if the pipe is expected to be subjected to freezing conditions repeatedly.

The heat fusion process gives the actual point of connection the same properties as the pipe and the joint, eliminating systematic weakness. After actual earthquake events, the pipe has been found to perform as well or better than metal piping in the same buildings.

Standard aquatherm pipe does not have an oxygen barrier, as oxygen permeation is very low and not found to cause any problems. In most applications, it will not affect the pipe if oxygen removal or treatment is added to protect the mechanical equipment. Submitting a chemical inquiry form can verify the suitability of the treatment.

Over an extended period of time, regular exposure to UV radiation will discolor the pipe and will weaken its physical integrity. The pipe can be stored outside unprotected for up to 6 months. The factory-issued bags that the pipe comes in will protect it from UV damage and should remain in place to cover the pipe until the pipe is ready to be installed.
The pipe may be protected by either a permanent wrap or insulation, or by using UV protective paint. 

Product availability

Product availability

aquatherm pipes are available in the following lengths:

  • aquatherm blue: 4 m or 5.8 m poles / depending on pipe diameter
  • aquatherm green: 4 m or 5.8 m poles / depending on pipe diameter
  • aquatherm red:  5.8 m poles / depending on pipe diameter

aquatherm green is approved for all potable water applications, food-grade applications, and NFPA 13D multi-purpose sprinkler systems.

aquatherm blue is approved for any non-steam mechanical applications, such as hydronic heating and cooling distribution and condenser water. It is also suitable for vacuum and many industrial/chemical applications.



aquatherm green is acceptable for direct food contact, or for use as process water or plumbing piping in food processing areas.

aquatherm piping systems have a total installed cost that is competitive with traditional metal systems. The exact level of savings is dependent upon the market price of the metal pipe and the experience level of the installers. 

quatherm pipe is extremely abrasion-resistant and is suitable for slurry applications. However, the exact suitability will depend on the type of slurry being conveyed and varies with each application. The engineer should submit a chemical compatibility form to the aquatherm engineering department. 

Most codes do not allow any plastic pipe to be used inside a building for transporting flammable gases. The codes for underground transmission currently only allow polyethylene and polyamide.

aquatherm piping systems are excellent for ground-source energy systems. PP-R and PP-RCT can be direct-buried and are not affected by soil. The pipe can also go from outside the building to inside the building without any transitions. 

aquatherm does not currently manufacture gravity-flow fittings for drainage applications. However, the pipe may be used for drainage applications if gravity flow fittings are not required.

Yes, aquatherm blue is a great choice for heating systems regardless of the other metallic (copper, steel) components present in the system. aquatherm has published some information about having copper with aquatherm green in domestic hot water recirculating (DHWR) systems, but that does not apply to heating loops. DHWR systems are continuously replenished with fresh chlorinated water. Closed loop heating systems demand very little make-up water. The water must be continuously replenished with new chlorine for there to be a concern. Additionally, free copper ions must be replenished in the water from corrosion/erosion of the copper components, occurring due to excessive velocity or corrosive water chemistry (no corrosion inhibitor).

In a heating system loop, neither chlorine nor copper ion replenishment would be occurring. The fresh water make-up is a small percentage of the system volume over long periods of time. The small amount of chlorine introduced is dissipated very quickly so there is not any long-term continuous exposure to high chlorine levels.
Most heating systems will also incorporate corrosion inhibitors when necessary to protect the steel and copper components from aggressive water chemistry. Systems and equipment design and operation will normally ensure the water velocity in the piping and boiler will not result in erosion/corrosion of the copper components.



Scrap material can be recycled, and this has been done with scrap material at aquatherm. The scrap material is not used to make new pipe, but instead it is recycled to make new products out of polypropylene.


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