NATURAL BENDS IN PEXGOL PIPES
When designing and installing Pexgol pipes in natural bends, high bending moments might be exerted upon the end connectors.
In case of self-restrained fittings no special care should be taken. In case of non-restrained fittings, special care should be taken to prevent excessive bending moment on the end-connectors due to forced installation.
See page 100 (Non-Restrained Fittings and Pullout Prevention Techniques).
Bending the Pipes
Use a suitable device, such as a winch or a lever, to bend the pipes. Remember that the pipe is rigid and considerable force is required for bending and fixing it – for example, 2 tons for a 110 mm pipe and 5 tons for a 280 mm pipe. Please exercise caution.
Bend the pipe carefully to avoid kinking. For best results, it is recommended to prepare a continuous pipe support with the radius of the pipe to be bent.
Then bend the pipe against it.
The installation is complicated since it is difficult to calculate in advance the exact length of the pipe. As a result, on-site adaptation (field welding) is necessary.
Proper Installation Procedure
1. Since the longer leg is more flexible, it is advised to connect the shorter leg to the existing counter-flange.
2. If necessary, install a fixpoint clamp before the fitting
to protect it during bending.
3. If the fitting is an electrofusion fitting, wait three cooling times (3x) before continuing with the next step.
4. Adjust the length of the longer arm.
5. Cut the length and install the fitting.
5.1. If the fitting is an electrofusion fitting with a stub-end (flared end) connection, perform the welding when the flared end is free (not connected to the counter-flange). Connect the flared end & flange to the counter-flange only after waiting three cooling times (3x).
5.2. If the fitting is an electrofusion fitting which connects the longer arm to another Pexgol or PE pipe, install a temporary fixpoint bridge before welding in order to protect the electrofusion fitting during welding. Disassemble the temporary fixpoint bridge only after waiting three cooling times (3x).
5.3. See Non-restrained fittings.
