PE pipe and PP compression fittings - open questions quickly explained
Application range and resistance of PP polypropylene compression fittings and PE pipe?
PP compression fittings are only suitable for PE pipe made of PE-LD, PE-HD, PE40, PE80 and PE100. All common PE pipes are covered. In our online shop PVC-Welt.de you will find the highest quality PE pipes:: PE-Rohr PE100 - SDR11 - PN16 bar
PP polypropylene and PE polyethylene are plastics that are inherently absolutely non-toxic, odourless and tasteless, making them suitable for transporting drinking water, wine, drinks and other liquids.
PE pipe and PP compression fittings can be installed above and below ground in a sand bed. For underground installation, the frost-free limit must be observed or the installation must be kept free of water during the frost period.
PE pipe and PP compression fittings are designed for cold water applications, even if the material may have a higher load limit, the items cannot be used for hot water heating (e.g. house construction).
PE pipe and PP compression fittings are NOT suitable for gas installations.
What thread do PP polypropylene compression fittings with thread have?
The common thread type in the plumbing sector is the BSP thread (Whitworth pipe thread). Therefore, in theory, all PP compression fittings with threads are compatible with threaded fittings made of other materials such as brass, stainless steel, or PVC-U.
Threads of this type are not self-sealing and require a suitable thread sealing material, such as Teflon tape. The internal thread is parallel and is identified with the abbreviation "Rp". The external thread is tapered and is identified with the abbreviation "R".
For clarification ...: the confusion with inch sizes – or why 1" is not exactly 25.4 mm
Teflon tape, sealing cord, hemp, and sealing paste: Thread sealing materials
Do not use swelling sealing materials: sealing and connecting plastic threads
Can PP compression fittings for PE pipe be used multiple times?
YES. The compression fitting can be loosened and the pipes removed at any time.
Can PE pipe and PP compression fittings be used for compressed air lines?
NO, PP compression fittings are designed exclusively for the transport of liquids in conjunction with PE pipe.
Are PE pipe and PP compression fittings suitable for ozone, chlorine and salt water?
PE pipes and PP compression fittings can be used in conjunction with ozone, chlorine and salt water without any problems. The limitation lies elsewhere: seals in unions, additional units, etc. Here it is essential to ensure that the seal is made of NBR, EPDM or higher quality. Maintain seals regularly, as incrustations can form on the seals due to adhering salts.
HTC compression fittings for PE pipe - our low-cost alternative without compromising on quality: PN 16 bar
PE pipes and PP compression fittings from HTC are ideal for high-quality, price-conscious installations for service water, irrigation and can also be used without restriction for the industrial sector as well as for drinking water supply in the private sector (without certification).
A wide range of connection options enables you to realise your project.
Internal thread generally with reinforcement ring - except for deviating image representation and note.For the highest demands: Unidelta PP clamp connectors, approval: DVGW, KIWA, WRAS
PE pipes and PP compression fittings from HTC are ideal for price-orientated installations for service water, irrigation and can also be used with restrictions for the industrial sector and drinking water supply in the private sector (without certification).
PE fittings made of polypropylene and PE pipes are an optimal pipe system for use in cold water technology and have become established above all in irrigation technology and drinking water supply. For use in drinking water supply, a high quality standard and components that have been tested for drinking water are essential. PE pipe clamp connectors made of polypropylene from UNIDELTA are tested and have DVGW, KIWA and WRAS approval. In combination with our DVGW-certified PE pipe of the highest quality in PE-100 quality, your project will succeed at the highest level.
PE pipes and PP polypropylene compression fittings
Structure of a PP compression fitting for PE pipe
| Number | Description | Material |
| 1 | Body | PP |
| 2 | O-Ring | NBR |
| 3 | Insert | PP |
| 4 | Grip-Ring | POM |
| 5 | Union nut | PP |
In contrast to PE pipes, PP polypropylene is a hard plastic. The grip ring cuts into the outside of the PE pipe when the union nut is tightened. This creates a stable, mechanical connection between the pipe and the fitting. The insert holds the O-ring in position so that it seals the PE pipe after installation. Chamfering is necessary and moistening is helpful when inserting the PE pipe into the fitting so that the PE pipe does not damage the O-ring or push it down into the pipe channel during insertion.
The clamp connector is a permanent connection but can be released at any time to be used elsewhere.
Processing PE pipes and PP polypropylene compression fittings
Unidelta Spa was founded in 1973 with the production of high and low density polyethylene and cross-linked polyethylene pipes for the construction of aqueducts, gas pipes, irrigation systems, fire extinguishing pipes, drainage pipes and heating systems.
Unidelta is a leader in the hydro-thermo-sanitary sector, thanks to a consolidated know-how of over forty years of experience, a guarantee of sought-after and certified quality in every phase of the production process (UNI EN ISO 9001: 2015 ) and in each of its products.
certified for:
- DVGW - Germany
- KIWA - Netherlands
- WRAS -Great Britain
- ITA - Italy
- ITB - Poland
- ETA - Denmark
Properties of PE pipes and PP compression fittings
PE pipe Pressure-temperature behaviour
Temperature/pressure diagram
PE pipe and PP compression fittings can be used for temperatures below 0°C - however, this requires an aqueous fluid, as the volume increases when ice forms and pipe and fittings can be damaged or destroyed.
As temperatures rise, the maximum permissible operating pressure, which is specified in PN (Pressure Nominal), decreases. Even if the two plastics PE (HDPE) and PP polypropylene allow higher temperatures, PE pipes and PP compression fittings are designed for cold water pipes.
UV resistance
PE pipe and PP compression fittings are UV-resistant due to the addition of UV stabilisers and can therefore also be used above ground without restriction. However, the frost-free limit must be observed or it must be ensured that the pipe is free of water if there is a risk of frost. Please note that even small amounts of water in unions can cause them to burst.
Drinking water and process water
High-quality components for drinking water and industrial water. The maximum working pressure of PN 16 bar says more than just the maximum pressure load. A fitting with a high value and higher quality components is certainly a better alternative than a component that is orientated towards the minimum.
Technical information
PE pipe PE-HD100:
- PE HD 100 Polyethylen High Density, SDR 11, DIN 8074/8075, EN 12201
- working pressure max. 16 bar at 20 °C
- Temperature - 20°C bis + 60°C
- PE pipes in the colour black with blue stripes for drinking water
- High chemical resistance, resistant to alkalis, salt solutions and inorganic acids, resistant to alcohol, oil and petrol
- Corrosion-resistant, resistant to UV rays, physiologically and toxicologically harmless
PP compression fitting for PE pipe:
- Dimensions and dimensions according to EN 712/713/715/911; ISO 3501/3503/3458/3459
- for installation with PE pipes according to ISO 11922; DIN 8072/8074; UNE 53131
- Thread (BSP) manufactured according to Standard ISO 7, DIN 2999
- max. PN 16 bar at 20°C Medium Water, Thread max. 10 bar, with reinforcement ring max. 16 bar
- All internal threads with reinforcement ring (16 bar) - unless noted separately
- PP polypropylene is absolutely non-toxic, odourless and tasteless, weather, ozone and UV resistant
