TWI Frequently asked questions
by Andy Knight
Plastic pipe is generally marked with all relevant information, using characters at least 3mm in height. All markings are permanent and are either embossed or heat indented into the pipes and fittings. Identification information mayinclude:
- manufacturer's name or identity mark
- material type
- relevant manufacturing Standard
- nominal outside diameter
- production batch number
- base polymer identification
- nominal pressure rating or SDR rating (PE only)
- intended contents
- sequential metre marking (coiled pipe)
In addition to the markings, the pipe colour may also indicate its intended use. The following are applicable to polyethylene pipe in the UK:
- orange or yellow for gas
- blue for potable water
- black for dirty water or chemicals
An example of a typical pipe marking:
WAVIN SUPASURE PE - BPS 225mm SDR 17 10bar 4-32-17 WATER 202 B 1 1 0 2002
This information is for a 225mm diameter, SDR17 10 bar rated polyethylene water pipe produced by Wavin. The manufacturing standard is WIS 4-32-17 and the manufacturing batch was 202 B 1 10 2002. BPS denotes the materialsupplier.
Related information
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What is electrofusion welding of thermoplastics?
Standards used for polyethylene pipe
