POLYFIT Pipe Selection
Cut length or “Plumb straight”
Although “Plumb Straight” coiled pipe is designed to effectively straighten when un-coiled, where the visual appearance of pipe is important, i.e. short visible sections of 22mm pipe in cylinder cupboards, pipe cut from straight lengths may be preferred.
NOTE: Polybutylene pipe must not be used for long permanently exposed
runs of pipe where appearance is important. Both straight and coiled pipes
Standard or Barrier
As barrier pipes contain an EVOH barrier layer to reduce oxygen ingress into the system through the pipe wall it is our opinion that these pipes must be used on central heating systems. When tested to DIN 4726 and DIN 4727 barrier pipes give an oxygen permeability less than the value of 0·1g (m3d) specified in DIN 4726. British Gas now accept central heating systems containing standard polybutylene pipes onto their maintenance and service contracts but this may result in additional checks and maintenance being carried out. The use of corrosion inhibitor in central heating systems is acceptable provided that the inhibitor is specifically designed for plastic piping systems and guidance on their suitability should be sought from the inhibitor manufacturer prior to adding to the system.
Both barrier and standard pipes can be used in hot and cold water supplies.
Pipe in pipe is available in grey only in the following variants:
- 10mm x 50m
- 15mm x 25 and 50m
- 22mm x 25m
Plain conduit pipe is available for 15mm and 22mm pipes in 25m and 50m lengths in black, red and blue.