PE / PP flange selection aid

Leckagen an Flanschverbindungen vermeiden

PE / PP Flange selection

Avoid leaks at flange connec­tions & improve connection to metallic fittings.

Find out in this guide which PE / PP flange is the best choice for your application.

Pre-welded joints in PE and PP pressure pipes often cause problems. That is why Reinert-Ritz has developed various problem solutions with which flange connec­tions can be reliably produced.

Find out more in this selection guide:

  • Why problems arise with PE 100 and PP welding neck seals
  • in which order you arrive at the optimal decision
  • how to use our selection tool to check whether the VP special flange is the best choice
  • whether you rely on the welding neck or prefer to use our HP flange

Leakage and nominal diameter offset: the problems with standard plastic welding neck seals

Leckagen und Versatz in Flanschverbindungen

The first plastic pipelines, PE (HD-PE) and PP, appeared and the connection dimen­sions were adapted for pre-welded joints of metal pipelines. However, this caused two problems: the internal offset between the plastic and the steel/cast iron/GRP pipe and fittings in particular, and insuf­fi­cient stability under many loads.

Reinert-Ritz has addressed these problems and today there are solutions to both problems: the special VP flange for the problem of internal misalignment and the HP flange for the problem of stability.

PE 100 and PP pressure pipes are used in many supply networks and indus­trial plants to transport liquids or gases. The pressure pipes are usually fitted with welding neck collars that are attached to metal flanges such as fittings. However, this design often has problems that can lead to leaks. The reason for the problems is that the internal diameters of many PE/PP pipe dimen­sions differ from the internal diameters of DN-oriented steel/cast iron or GRP pipes. As a simple solution, pre-welded collars are provided with a bevel on site. They are usually handled roughly with an angle grinder, which makes the collars unstable and can lead to leaks. To avoid these problems, it is important to select the right flanges at the planning stage.

The VP special flange is the solution for connecting PE 100 / PP pipes to fittings, steel, cast iron and GRP flanges.

Der Sonderflansch VP ist in Flanschverbindungen besonders kosteneffizient

The VP flange enables fittings to be integrated cost-effectively.

Der Sonderflansch VP ist in Flanschverbindungen unkompliziert zu installieren

Instal­lation is straight­forward & the flanges are available in different sizes.

Der Sonderflansch VP hat in Flanschverbindungen eine hohe Stabilität

VP flanges are more stable than conven­tional flanges.

Optimalier Durchfluss durch minimalen Versatz

Minimal offset & improved flow properties as well as reduced deposits.

Virtual flange finder

You can find out whether the special flange VP is the right choice for your appli­cation with our flange finder. Simply set the pipe diameter suitable for your appli­cation (e.g. DN/od 160) and read off to the left and right which DN/flange combi­nation fits best:

Show product 
Special Flange VP VP
Show product 

Set pipe

DN 150
SDR 17 / 11*
∅ 160
DN 125
SDR 11
DN 200
SDR 17*
∅ 200
DN 150
SDR 17/11
DN 250
SDR 17*
∅ 250
DN 200
SDR 17/11
DN 300
SDR 17*
∅ 315
DN 250
SDR 17/11
DN 500
SDR 17*
∅ 500
DN 400
SDR 17/11
DN 600
SDR 17*
∅ 630
DN 500
SDR 17/11

Do you have an appli­cation that does not corre­spond to our tool? Then describe your appli­cation here. 

We can help you select the right flanges.

Like many of our customers, make the VP special flange your standard for connecting to fittings. 

PE 100 / PP welding neck collars: When is the standard welding neck collar the right choice for your pressure pipe?

Designers and users of standard plastic welding neck seals know the problem. They are often difficult to seal during instal­lation. In addition, leaks often occur at flange connec­tions during the service life of the PE / PP pressure pipe. Some flange dimen­sions are easy to get tight, some require a lot of dexterity and others are highly critical. Pre-welded collars are not designed to be suitable for plastic, the plastic is overloaded and deforms over the course of its service life. The ambient condi­tions also influence the tightness of the connection — extreme cold or heat make instal­lation even more difficult. The result: expensive mainte­nance and repair work as well as production downtime.

Leckagen und Versatz in Flanschverbindungen

The typical problems with PE 100 and PP pre-welded bundles:

❗️ Standard plastic welding neck collars are often difficult to get tight

❗️ Leaks frequently occur at flange connec­tions during the service life of the PE / PP pressure pipe

❗️ Welding collars are not designed to be suitable for plastic and the plastic is overloaded and deforms over the course of its service life

Flanges must be able to be mounted reliably even under difficult condi­tions. They therefore need suffi­cient reserves against overloading. Regardless of whether the overload is caused by pressure, environ­mental influ­ences or assembly.

Pre-welding waistband checklist!

Many customers are unsure whether they can use PE 100 / PP bundles for their appli­ca­tions. There is often a mixture of positive and negative experi­ences with the use of welding neck bands. The decision also has an influence on the quality of the penstock.

We have created a checklist for our customers. You can use the checklist to assess how critical your appli­cation is. If in doubt, it is better to use the reliable HP flange.

Test our checklist now and decide whether pre-welding tapes are suitable for your application:

  • Unerfahrene Monteure. Größer PN 10 ist in der Regel kritisch
  • Kritische Anwen­dungen. Größer DN/od 500 (Flanschmaß DN 500) sind in der Montage herausfordernd
  • Anwen­dungen mit zusät­zlichen Belas­tungen. Freiver­legte Druck­rohrleitungen, Biege­be­las­tungen, Temper­a­ture­in­flüsse sind kritische Anwen­dungen für den Standard-Vorschweißbund.
  • Große Rohrdurchmesser. Kritische Anwen­dungen, bei denen Ausfälle zu höhen Schäden führen, sind dringend zu beachten.
  • Abweichungen von den üblichen Druck­stufen. Unerfahrene oder ungeschulte Monteure können ebenfalls ein Problem darstellen.

Are you unsure what the right flange connection is for you? Or would you like to do without a flange connection, but don’t have a solution?