Support - aquatherm FAQs

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What lengths does the pipe come in?

In sizes from 16mm to 125mm, the pipe comes in standard 4 metre lengths. Larger diameters (160mm to 630mm) come in 5.8 metre lengths.  See aquatherm’s catalogue or check out our website.

Does aquatherm pipe still require insulation?

PP-R has a natural insulation value, which can allow for a system to use less insulation than it would have with metal pipes or even other plastics. However, in some applications, insulation will still be required. It is up to the engineer on the project to determine how much insulation will be installed and where. Unless an area is exceptionally humid, aquatherm recommends not insulating domestic cold water piping.

aquatherm pipe should be installed with insulation following the same ASHRAE standards as steel or copper. In hot water applications it is sometimes possible to leave the fittings uninsulated as the pipe has a natural R value of 1.4 per inch of material. The overall heat loss with the fittings uninsulated in some cases may be equal or less than insulated steel or copper.

What dimensions does the pipe come in?

aquatherm piping systems are manufactured based on metric OD. Green pipe and lilac pipe are available in sizes from 16mm to 355mm and blue pipe is available from 16mm to 630mm.

What applications is lilac pipe approved for?

Lilac pipe is suitable for rainwater, reclaimed water, and recycled water distribution. Lilac pipe meets ASTM F2389 and CSA B137.11 under the American Reclaimed Water Standards and is coloured purple to avoid crossover with potable water systems. This water saving initiative has become popular in Australia and New Zealand and has proven particularly successful in Green Building applications and rainwater harvesting for industrial applications etc.  aquatherm lilac pipe uses the same fittings as the green pipe and blue pipe systems.

What applications is green pipe approved for?

aquatherm green pipe is approved for all potable water applications and all food-grade applications. Green pipe can also be used in hydronic applications and other industrial applications where the higher temperature/pressure capabilities are needed. Please contact aquatherm NZ for approvals and certification.

What applications is blue pipe approved for?

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

Can I use aquatherm piping for food processing applications?

aquatherm green pipe has the NSF 51 certification which is the standard used to determine if a material is listed as “Food zone”. NSF 51, Section 4.1 lists all of the requirements by the NSF which aquatherm green pipe has met.

Can the pipe be used in RO/DI systems?

aquatherm pipe is a great option for use with RO/DI water systems. aquatherm pipe is used regularly with ASTM type II and III water systems which are the most common RO/DI water systems for labs and other uses. aquatherm pipe has also been tested with up to 18 mega-ohm (ultra-pure) ASTM type I water. At this purity level there may be an extremely low level of colorant leaching.

Is the pipe approved for medical gases?

At this time, aquatherm pipe is not approved for use with medical gases.

Is the pipe approved for compressed air?

Yes, aquatherm pipe is suitable for use as compressed air piping. P-PR is an excellent material for compressed air transportation with fusion welded joints, stabilised pipe material with fibre construction and corrosion resistant material.  Please note that the air must be cooled to at or below the rated temperature of the pipe system before coming in contact with the aquatherm pipe. Please refer to the catalogue for permissible pressures and temperatures.  aquatherm blue is predominately used for compressed air systems and has been used in New Zealand now for 18 years in notable large commercial installations such as Fisher & Paykel, Vertex and many other large industrial plants, commercial garages and general compressed air applications.  For support and information on certification requirements please contact our Technical department.

How do the costs of aquatherm compare to other systems?

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 of the installers. Contact your local rep or distributor for material pricing. You can also create an estimated material and labour cost using the aquatherm Parts Tool and a list of the materials you are planning to install.

Can the pipe be used for natural gas?

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.

Can the pipe be used for ground-source heating and cooling?

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

Can the pipe be used for drainage applications?

Aquatherm does not currently manufacture gravity-flow fittings for drainage applications. However, the pipe has been used for drainage with Solo Plastics manufacturing fittings for drainage.

Can the scrap material be recycled, and is anyone actually doing this?

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.

Are the beads of plastic on the inside going to be a problem?

PP-R is smooth and causes less friction than other, more commonly used materials, so the incidental beads that may form during the heat fusion process are not consequential. Larger beads, caused by excessive heating and pressure, may cause restrictions and block the pipe. Blocked connections should be removed and replaced. The installer is responsible for making sure that the connections are clear and unobstructed.

Can the pipe be used for slurry applications?

aquatherm pipe is extremely abrasion-resistant, durable and is suitable for industrial 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 aquatherm NZ.  Please contact us at

What kinds of fire-stopping does aquatherm pipe require?

As with any other piping material that penetrates a fire barrier, the aquatherm pipe must be installed with an approved firestop system. The required ratings and listings will depend on the specific type of fire barrier being penetrated. Firestopping systems are available for use with aquatherm piping in many common types of floor/ceiling and wall constructions. The listings are the responsibility of the firestop manufacturers, who should be consulted on any specific construction details and the acceptable use of their products with aquatherm piping. A listing of firestop manufacturers that have products compatible with aquatherm is found on the website. (

Can the pipe be damaged by sunlight?

Over a long enough period of time, regular exposure to UV radiation will discolor the pipe and may 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 cover or using an elastomeric paint.

Does aquatherm pipe have an oxygen barrier?

Standard aquatherm green pipe does not have an oxygen barrier, Standard PPR has a very low oxygen permeation and has not been 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.  aquatherm blue is predominately used for mechanical applications, chilled water and heating systems as the pipework is specifically constructed for this application.

What is the thermal expansion of PPR

The thermal coefficient of linear expansion aquatherm green faser composite pipe is only 0,035 mm/mK and 0,03 mm/mK for non-faser pipe.

What training does an installer need to work with aquatherm pipe?

Plumbers and pipe fitters who are installing aquatherm pipe need to be trained by an aquatherm trainer. Installations done by untrained installers cannot qualify for the warranty. aquatherm courses help supplement the skills a plumber or pipe fitter learned in school and over the course of his career by focusing on heat fusion techniques and aquatherm-specific installation concerns. The course takes only 2-3 hours to complete and will quickly save days of time on the job site.

For more information, contact aquatherm NZ

How does aquatherm pipe transition to other systems?

Aquatherm has two main forms of transitions: threaded connections and flanges. Flange adaptors are available from 1” (32 mm) through 24” (630 mm). Threaded connections are available from ½” (32 mm) through 4” (125mm). There are also adapters for connecting to PEX (crimp and expansion), groove-adapters, and copper stub-outs.

Can I use a band saw to cut Aquatherm pipe?

Band saws may be used to cut Aquatherm pipe. As with circular saws, the blade used should always be one that is intended for use with wood or plastic.

Can I use a chamfer and cold-ring tool when doing socket fusion?

Yes, provided they are designed for use with metric OD polypropylene pressure pipe. Tools intended for polyethylene (HDPE, MDPE) should not be used.

Can polyurethane foam insulation be used around the pipe in wall and ceiling spaces?

Yes, provided the foam is installed in accordance with the manufacturer’s instructions. These foam products will give off heat when curing, and can reach temperatures that may damage plastic pipe if not installed properly. This is normally achieved by ensuring the thickness of each pass is at or below the manufacturer’s recommendations. Pipe inserts are not allowed for use as will not allow movement of pipe.

Can the fusion joints be taken apart if I need to modify the system?

A heat-fused joint becomes one solid piece of material, and it cannot be undone. This is what creates a no-leak-path piping system, and what makes our leak-free joints the strongest part of the piping system.

How does the pipe stand up to being frozen?

aquatherm piping is considered to be freeze‐tolerant, meaning that it will not rupture if accidentally allowed to freeze.

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.

How is aquatherm pipe affected by thermal expansion?

Aquatherm pipe with 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 Catalog.

Can the pipe be buried without thrust blocking?

When buried, aquatherm pipe is able to absorb its own stresses and does not need thrust blocking. Anchors may still be necessary where buried pipe enters a building foundation or other locations to minimise pipe movement.

How close together can fusion outlets be placed on the pipe?

Fusion outlets can be placed very close together. This is usually limited by the size of the iron being used. On smaller size pipe it is possible to create manifolds with the outlets roughly 50mm on centre.

How do I account for the pressure due to building height in a high-rise project?

aquatherm piping is often used in high-rise construction. As with any piping material, the operating pressure, including the pressure due to the elevation above the lowest point in the zone, must be less than or equal to the pressure rating of the pipe. If the pipe is used as a riser for the full height of the building, then this height must be included in the operating pressure for the pipe at the lowest point.

How do the labour times using aquatherm piping compare to other products?

The labour times on PP-R are comparable to the labour on glued systems or copper press fittings in small sizes and butt-fused HDPE in large sizes. Installers typically see more savings as they becomes more familiar and comfortable with heat fusion. Labour savings can be significant compared with metal piping such as sweating/brazing copper or welding steel.

How does the pipe hold up to seismic activity?

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.

How much noise does the pipe generate?

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.

If the pipe provides a thermal barrier, then how can it be used in the black panels or radiant and geothermal loops where heat conduction is necessary?

When aquatherm tubing or smaller diameter pipe is used the wall thickness is thin enough that the thermal barrier is insignificant. The aquatherm black panels use rectangular tubes to increase the radiant surface area. These advantages allow PP-R to be used for radiant and geothermal applications more effectively.

If you increase the heating time (per aquatherm recommendations), do you also need to increase cooling time? By what metric?

When installing at colder temperatures, the heating time must be increased as noted in the installer manual. Cooling time does not need to be increased.

Is aquatherm pipe affected by corrosion or scaling?

Polypropylene will not corrode and is not affected by scaling, the way many other materials are. It also does not support microbiological growth. Information on pipe longevity can be found in the aquatherm catalog.

Is the pipe sizing comparable to steel or copper pipe?

The aquatherm piping systems are based on standard dimension ratio, or SDR. This means that for a given SDR, all pipe sizes will maintain the same ratio of OD to wall thickness. The benefit of this is that all pipe sizes of a given SDR have the same pressure rating. This is different than steel and copper which have different pressure ratings for different sizes of the same schedule, where the pressure rating decreases with larger sizes.

For those more accustomed to metal pipe, the different SDR’s of aquatherm pipe can be thought of as different schedules or types. The wall thickness on SDR 7.4 will be more comparable to schedule 80, while SDR 11 is closer to schedule 40.

Is there concern with tamping, or driving over buried pipe, in regards to its ability to remain undamaged?

Compaction of sand around the pipe will not harm the pipe and is often necessary to ensure the proper soil conditions for embedment. The burial depth required for safe driving over the pipe is a function of the soil properties and pipe SDR. See the following technical bulletin.

What are the pressure and temperature ratings of the pipe?

Working pressures and temperatures for aquatherm pipe can be found on page 23 and 25 of the catalogue and on the website.

What chemicals are safe to use with Aquatherm pipe?

Polypropylene is non-reactive with many chemicals, but chemical compatibility also depends on concentration and temperature. 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, by email or by fax to aquatherm NZ and we can have it tested at our laboratory in Germany.

What is the chemical makeup of the pipe?

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 colour pigments and stabilisers.

What is the friction factor or Hazen-Williams coefficient, and how does it compare to other materials?

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).

What is the vacuum rating for the pipe?

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

What kind of hanger does the pipe need?

All pipes should be fastened with only aquatherm green rubber compound fasteners with expansion spacers. Only aquatherm approved brackets must be used to allow for movement.

What kinds of fusion techniques does aquatherm pipe use?

aquatherm pipes are joined by four variations on basic heat fusion. Socket fusion uses female fittings that go over the pipe. Outlet fusion is fusing an outlet to a piping system by using a drill to make a hole in the pipe, then heating the hole and the fusion outlet and then pressing the outlet into the heated hole. Butt fusion joins pipe together end-to-end. Butt fusion is done on piping 160mm and larger. Electrofusion couplings are also available for joining pipe in very confined spaces where the pipe cannot be moved.

What options are available for hot-tapping?

There are several options available for hot-tapping using mechanical saddles. The manufacturer of the saddle fitting should be consulted to determine whether a specific product will work with the Aquatherm pipe based on pipe OD and wall thickness. Fusion-weld hot-tapping fittings are currently under development.

What paint(s) can I use to protect Aquatherm pipe from UV exposure? How long will the product last?

Due to the flexible nature of PP-R, most forms of paint are unacceptable for a UV protective coating. We recommend the use of a heavy-duty, water-based, elastomeric acrylic coating, which can adjust with the pipe without cracking. The life cycle performance of any of these products will depend on many installation and use factors. The manufacturer of the coating should be consulted for this information.

For more information contact aquatherm NZ

What substance(s) can I use to clean the pipe prior to fusion?

Remove standing dirt and oil using an alcohol-based cleaner. Use only isopropyl alcohol, as denatured alcohol may contain impurities and other chemicals that could affect the integrity of the fusion joint.

What temperature is the iron at for heating the material?

The iron will normally operate at about 500°F (260°C) for socket fusion, and 410°F (210°C) for butt fusion.

When the bare pipe burns, is the smoke toxic?

The Aquatherm piping is combustible and will burn in a fully developed fire. The combustion products are carbon dioxide and steam/water. Smoke toxicity testing has been done on the piping and have confirmed not only that the smoke meets the most stringent toxicity requirements, but also that it consists of carbon dioxide and water, with a few other constituents at trace levels well below indoor air quality guidelines and any smoke toxicity concerns.

Why can’t I dry fit the aquatherm fittings?

The openings of the fittings need to be slightly smaller than the outside of the pipe in order for the heat fusion process to work correctly. This helps to avoid leaving any joints unconnected.

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