A dishwasher manufacturer needed 6.35 × 4 mm PE tubing for an internal hot-water line, and the PE options first reviewed were listed for only 0–55 °C. This case describes how we moved to a PE-RT (polyethylene of raised temperature resistance) material, tested a natural-color sample with the customer’s own fitting, and then supplied both natural and custom dark-blue tubing on a recurring basis.
- Application
- Dishwasher hot-water line
- Material
- PE-RT, custom material
- Size
- 6.35 × 4 mm
- Supply
- Quarterly since Aug 2025
Quick summary. Size 6.35 × 4 mm in natural and custom dark blue; working water temperature about 50–70 °C with a target of about 80 °C; tested with the customer’s fitting in a heated dishwasher-powder solution; regular quarterly orders since August 2025. PE-RT is a custom material route here, not a standard model in our PE tubing range.
Customer application requirements
The tubing would carry hot water through repeated circulation. The customer named dishwasher tablets, dishwasher salt and dishwasher powder, plus a small amount of acidic descaling agent, as the chemical exposure. The tube also had to stay stiff enough at temperature to remain locked in the fitting that holds it directly.
- Tubing size: 6.35 × 4 mm, for both colors
- Water temperature about 50–70 °C, target resistance around 80 °C
- Repeated hot-water circulation and the customer’s specified cleaning products
- No whitening, swelling or cracking under the intended conditions
- Firm retention in the customer’s fitting at elevated temperature
- Natural and custom dark-blue options
Why the previous tubing was not suitable
The tubing the customer used before did not meet the requirements of the dishwasher system, so they looked for a PE-based tube with a higher temperature range and better behavior after hot-water exposure. The PE options first reviewed were listed for about 0–55 °C, below the 80 °C target. For the standard PE listed ranges, see the PE tubing guide.
PE-RT material selection
PE-RT is a PE-based material developed for uses that need more temperature resistance than some conventional PE grades. We worked with our raw-material supplier to identify a suitable PE-RT material and produced samples in the required size. A product specification sheet for this tubing is available on request.
Natural-color sample and testing with the customer’s fitting
The customer supplied the fittings, so the tube was evaluated together with the actual connection rather than on its own. The first sample was natural color: PE-RT, 6.35 × 4 mm.
Preliminary hot-water soak. A natural-color sample was soaked in 100 °C water for 20 minutes. After the fitting at one end was removed, a firm retention mark was visible on the tube.
Dishwasher-powder solution test. The customer specified a solution of 30 g of Finish® dishwasher powder in 1,000 ml of water, stirred until even. The test conditions were deliberately above the 50–70 °C working range:
- Heat the solution to 100 °C, then hold it at 90 °C.
- Immerse the tube sample for 10 minutes.
- Remove it for a 20-minute interval.
- Repeat the immersion and interval two more times, for three 10-minute immersions in total.
After the final cycle the sample was inspected and pull-tested by hand with the customer’s fitting. The tube was only slightly softer and stayed on the fitting. The check was a manual pull test, so no pull-force value is given. The result met the customer’s expectations for the sample stage. The test used the powder solution only; salt, tablets and descaling agent were not run as separate tests.
Custom dark-blue tubing
The customer then asked for a dark-blue version in the same size, so the line can be identified quickly during assembly, installation and maintenance. The color and specification were confirmed with the customer before regular production.
Repeat orders since August 2025
Since August 2025 the customer has placed quarterly orders for both the natural and the dark-blue tubing, each in 6.35 × 4 mm.
The work went beyond picking a standard tube: reviewing the application, finding a PE-RT material, sampling, testing with the customer’s fitting, developing the blue version and supplying both colors.
Key takeaways
- Review temperature and chemicals together. Hot water and cleaning products were assessed as one condition.
- Test with the real fitting. Stiffness at temperature shows up as fitting retention, so the tube was checked in the customer’s own connection.
- Color is part of the specification. Dark blue was a practical identification requirement, not decoration.
Related reading: how to specify tubing, how to test tubing samples and PU vs PE tubing.
PE-RT dishwasher tubing FAQ
What tubing size was developed for this dishwasher application?
6.35 × 4 mm, for both the natural-color and the dark-blue versions.
Why was PE-RT considered?
The customer needed a higher temperature range than the PE options first reviewed, which were listed for about 0–55 °C against a target of around 80 °C.
What is PE-RT?
PE-RT is polyethylene of raised temperature resistance, a PE-based material for uses that need more temperature resistance than some conventional PE grades. Limits depend on the specific specification, dimensions and operating conditions.
Can conventional PE tubing be used in a dishwasher?
It depends on the exact material, size, temperature, chemicals, fitting design and operating conditions. In this project the PE options first reviewed did not reach the customer’s target temperature.
Was the tubing tested with the customer’s fitting?
Yes. The customer supplied the fitting, and the natural-color sample was evaluated together with it.
Is a specification sheet available?
Yes, on request. Contact YUANNAI TUBE with your application and size.
Need a tubing material for a special application?
If your application sets requirements for temperature, chemical exposure, stiffness, color or fitting retention, send us the conditions. We review them with our raw-material suppliers and develop samples in your size for your connection method.
