For reasons I won't go into at the moment, I have been trying for some time to find copper or s/steel inserts for 32mm MDPE pipe. On my trawls through the internet I have learned that inserts (universally plastic) are required for metric mdpe pipe, but not for imperial. I couldn't quite grasp the reasoning behind this, as both are polythene and the black imp pipe I have seems a little softer than the blue metric stuff. Why one and not the other?
Then I found a few sites which gave some sort of answer, including this: To meet the requirements of the Water Regulations Advisory Scheme (WRAS) it is necessary to use an insert or liner with metric MDPE service pipe to BS 6572:1985, BS 6730 and HPPE to WIS 4-32-13 for below ground use in the UK. For polyethylene pipe other than the PE pipe material shown above, use of the liner is optional. If a liner is not used the connection will still substantially exceed most international performance requirements.
This implies that the use of a liner is determined primarily by regulation, not by need. But why does the regulation require inserts for metric pipes only? It would be easy enough to state that all new PE joints should use inserts. And does that quote mean that inserts are only required underground?
So why, technically, are inserts required? Does the pipe collapse without them, and if so why doesn't imperial pipe collapse?
Then I found a few sites which gave some sort of answer, including this: To meet the requirements of the Water Regulations Advisory Scheme (WRAS) it is necessary to use an insert or liner with metric MDPE service pipe to BS 6572:1985, BS 6730 and HPPE to WIS 4-32-13 for below ground use in the UK. For polyethylene pipe other than the PE pipe material shown above, use of the liner is optional. If a liner is not used the connection will still substantially exceed most international performance requirements.
This implies that the use of a liner is determined primarily by regulation, not by need. But why does the regulation require inserts for metric pipes only? It would be easy enough to state that all new PE joints should use inserts. And does that quote mean that inserts are only required underground?
So why, technically, are inserts required? Does the pipe collapse without them, and if so why doesn't imperial pipe collapse?
