Bottle traps appear to be designed to connect directly to the waste plug of the basin or whatever with a thread that the trap nut screws onto. However, I want to connect the trap inlet to the end of a 40mm push fit waste pipe, which doesn't have a thread. What am I to do?
There are several options, but the easiest is to purchase an adjustable height trap and remove the section that fits to the underside of the basin and replace it with a standard piece of push-fit waste.
As it happens, I also have a telescopic bottle trap for another purpose and while waiting for a reply here I had a look at it and discovered exactly what you suggest. Always nice to have a second opinion confirm a plan's a good one. Diolch.