Installation tube made of polypropylene does not cause trouble plumbing, especially if it is a small diameter tube. But since the large-diameter and time spent on the strength "construction" of the pipeline increases. In order to facilitate the installation of the "forgotten" frames, we used a method that does not require additional expenditure of energy, time and money on large-diameter tee.
Using the method, without coupling, direct tie-in pipe technology and documented or where not described.
Therefore, the author is not liable for your actions when dealing with piping and does not encourage you to take action.
In one of the houses, in the basement, we needed to do a tie-in large-diameter pipes. For the installation of pressure gauges and drain taps. For this we need a pen on a tree with a diameter of 18 mm. About how to modernize, I wrote in the previous state- link.
Before drill pipe must be emptied, drain. Take a screwdriver and a nozzle hole is drilled.
The thickness of the large diameter pipe walls allows to produce sealing of tube 20 mm.
On a dry pipe protses produce diffusion bonding.
Box is ready, the visual range is shown for illustrative purposes only.
As a result, you can make the installation of valves for emptying 'lezhanok "or mount devices and tie.
Practice has shown that such tie withstand the pressure and do not cause trouble in the maintenance of utilities.
I hope I have conveyed to you useful information if this is the case, then let mark plumber "kid-skin"For effort! Thanks.