Push-fit systems · Tool
Transitions to other systems: first identify, then measure, then the right transition
Almost every refurbishment starts at a pipe that is already there – copper, galvanised steel, a third-party composite pipe. The good news: a transition is always possible, in case of doubt via thread. This page leads there in three steps: identify the pipe type (colour, embossing), measure the outside diameter (callipers or string) – and the existing-pipe identifier names the matching iFIT transition part.
- Input
- Pipe type or outside diameter of the existing pipe
- Result
- Transition route (direct or via thread) · example item with GF code
- Sources
- GF iFIT product range 07/2025 · dimensions of the pipe standards
- Basic rule
- Transitions are always possible – in case of doubt via thread (experience)
Step 1: Identify the pipe
Copper tube is reddish brown to green with tarnish and carries an embossing such as “Cu 15x1”. Steel threaded pipe is grey (galvanised) or black and often has a visible thread at the end. Composite and plastic pipes are white, grey or coloured and carry a print with system name and size (“16x2”) – read this print, it decides the transition. More on reading embossings and prints is on our German page on reading markings; if you cannot place the component at all, the component finder helps.
Step 2: Measure the outside diameter
With callipers directly on the pipe – or with a piece of string: measure the circumference and divide by 3.14. The typical values: copper 15, 18 or 22 mm; steel threaded pipe 21.3 mm (½ inch), 26.9 mm (¾ inch), 33.7 mm (1 inch); composite pipe usually 16 or 20 mm. Risk of confusion: 21.3 mm steel looks confusingly like 22 mm copper – the embossing and a magnet help.
Step 3: the existing-pipe finder
Enter the outside diameter or choose the pipe type – the finder names the matching iFIT transition.
The transitions as a table
| Existing pipe | Outside ø (mm) | Markings | Transition | Example (GF code) |
|---|---|---|---|---|
| Copper tube (DN 12) | 15 | reddish brown to green tarnish, embossed “Cu” with size 15x1 | iFIT press transition module to copper 16/20 – 15 mm (direct) | 762 101 293 iFIT transition to copper 16/20-15 mm · in stock |
| Copper tube (DN 15) | 18 | reddish brown, embossed 18x1 | via thread: on the copper side a solder fitting or press transition with ½ male thread, iFIT transition module with ½ female thread (via thread) | 762 101 267 iFIT transition module with female thread 16/20-1/2 · in stock |
| Copper tube (DN 20) | 22 | reddish brown, embossed 22x1 | via ¾ thread: transition with ¾ male thread on the copper side, iFIT transition module with ¾ female thread (via thread) | 762 101 268 iFIT transition module with female thread 16/20-3/4 · in stock |
| Steel threaded pipe (galvanised or black) (DN 15 (½ Zoll)) | 21,3 | grey (galvanised) or black, thread at the end, longitudinal weld visible | iFIT transition module with ½ female thread onto the male thread of the pipe or fitting (via thread) | 762 101 267 iFIT transition module with female thread 16/20-1/2 · in stock |
| Steel threaded pipe (DN 20 (¾ Zoll)) | 26,9 | as ½ inch, embossing or colour stripe depending on the manufacturer | iFIT transition module with ¾ female thread (via thread) | 762 101 268 iFIT transition module with female thread 16/20-3/4 · in stock |
| Steel threaded pipe (DN 25 (1 Zoll)) | 33,7 | as ½ inch | iFIT transition module with 1 female thread (dimension 25/32) (via thread) | 762 101 280 iFIT transition module with female thread 25/32-1 · in stock |
| Multilayer composite pipe of another system (DN 12) | 16 | white or grey, printed with system name and 16x2 | never push in directly: third-party pipe via the press transition of its own system with ½ male thread and iFIT transition module with ½ female thread (via thread) | 762 101 267 iFIT transition module with female thread 16/20-1/2 · in stock |
| Multilayer composite pipe of another system (DN 15) | 20 | printed 20x2 with system name | via ¾ thread as for 16 mm (via thread) | 762 101 268 iFIT transition module with female thread 16/20-3/4 · in stock |
| Plastic pipe PE-X or PB of another system (DN 12–20) | 16–25 | white, transparent or coloured, printed with pipe type (PE-X, PB) and size | via thread: the system’s own transition with male thread, iFIT transition module with female thread (via thread) | 762 101 267 iFIT transition module with female thread 16/20-1/2 · in stock |
| Valve or angle valve with thread (½ Zoll) | – | female or male thread on the valve | iFIT transition module with ½ male thread (onto female thread) or ½ female thread (onto male thread) – for wall connections the tap connection module (direct) | 762 101 265 iFIT transition module with male thread 16/20-1/2 · in stock |
The one rule that is never broken: a third-party composite or plastic pipe is never pushed directly into the iFIT adapter – grip ring and O-rings are not matched to it. The route goes via the press transition of the other system with male thread and the iFIT transition module with female thread.
If it is not going to be a push-fit system after all
Sometimes another method is shorter at the existing pipe: a press transition for 18/22 copper, a compression fitting at the angle valve. The comparison is on methods compared; the systems for planners and fitters are in the press systems section.
Not sure about the existing pipe?
Tell us the embossing or print and the measured outside diameter – we name the matching transition and supply it from stock.
Send an inquiryYour inquiry to Zickwolff
Send us what you have – designation, standard, quantity, date. We will clarify the rest with you.
One item or a question
Send inquiry
Not in stock? We procure it – single items too.
Designation, standard and quantity are enough.
Several items
Send bill of materials
200 items? One parts list is enough – we deliver complete.
Attach it as a file.
Helpful if already known: project and country, date needed, certificates, packaging and language of the packing lists. If anything is missing, we will ask.
It is urgent
Request express
When do you need it? Express delivery, to the site if required.
Tell us by when you need the material – we will tell you what is possible.
Technical basis: GF iFIT product range (07/2025), GF iFIT brochure gfps-39052 (12/2023) – authorised-dealer material, use approved; pipe dimensions according to the dimensional standards of the respective pipe type. The basic rule “in case of doubt via thread” is in-house experience. Information without guarantee – the binding approval remains with the manufacturer.