EVOH makes the pipe slightly stiffer
The EVOH layer in a PEX EVOH Pipe adds some rigidity to the wall. This reduces flexibility compared to standard PEX. The pipe is still flexible enough for most installations. Example: a PEX EVOH Pipe is less flexible than non-barrier PEX.
Bending radius is larger
The minimum bending radius is larger for PEX EVOH pipes. Standard PEX has a 5x diameter radius. PEX EVOH typically requires 6-8x diameter. Example: a PEX EVOH Pipe needs more space for bends.
EVOH thickness affects stiffness
Thicker EVOH layers reduce flexibility more. Thinner layers allow easier bending. The overall pipe design also influences stiffness. Example: PEX EVOH Pipe flexibility varies with construction.
Comparison to PEX-AL-PEX
PEX EVOH is more flexible than PEX-AL-PEX. Aluminum is stiffer than EVOH polymer. EVOH provides a good balance of flexibility and barrier. Example: a PEX EVOH Pipe is easier to install than aluminum barrier pipes.
Using bending springs
Bending springs prevent kinking during installation. They support the pipe during bending. They reduce the risk of damage. Example: PEX EVOH Pipe benefits from bending springs.
Cold temperature bending
Cold temperatures make the pipe stiffer. The EVOH layer becomes less flexible. Warm the pipe slightly if needed. Example: PEX EVOH Pipe bends better at moderate temperatures.
Hot bending technique
Heat the pipe to 50-60°C for easier bending. This softens the PEX layers. The EVOH becomes more flexible. Example: PEX EVOH Pipe can be bent hot with caution.
Minimum bend radius by size
20mm pipe: 120-160mm minimum radius. 25mm pipe: 150-200mm. 32mm pipe: 192-256mm. Example: PEX EVOH Pipe follows these guidelines.
Example: bending a 20mm pipe
A plumber bends a 20mm PEX EVOH pipe. He uses a bending spring for support. The pipe bends to a 150mm radius. Example: PEX EVOH Pipe bends without kinking.
Example: standard PEX comparison
Standard PEX bends to a 100mm radius. PEX EVOH needs a 150mm radius. The EVOH layer adds some stiffness. Example: PEX EVOH Pipe requires more space.
Use fittings for tight turns
For tight radius turns, use fittings instead. Elbows and tees provide reliable turns. This avoids stressing the pipe. Example: PEX EVOH Pipe works best with fittings for tight spaces.
Final flexibility summary
PEX EVOH Pipe has reduced flexibility compared to standard PEX. The minimum bending radius is 6-8x pipe diameter. Cold temperatures reduce flexibility further. Hot bending can help in some cases. Use bending springs for support. For tight turns, use fittings instead. PEX EVOH Pipe offers a good balance of barrier and flexibility for most installations. Example: a practical, easy-to-install pipe for heating systems.