Connecting to an existing PolyPipe screwed access cap

[BHI]

Putting in an en-suite, I did all of the 40mm solvent weld plumbing back to the soil stack, but left the final fix of a shower tray to a local plumber.

However, where a 135-degree tee had been left for a ventilation pipe to an air admittance valve (due to the length of the run to the main soil stack), he solvent welded in a 40mm PolyPipe access cap. Not sure that this will now pass building regs as the inspector kept going on about needing AAVs.

This has a cap that screws inside the fitting (rather than screwing outside the fitting), so it won't fit a 32mm pipe or anything inside due to the thread.

Whereas I'd usually just chop it off below the fitting, as he's welded it straight in to the 135 tee means this is nigh on impossible. Also, the other ends of the 135 tee have a flex pipe to the shower trap, and the other straight in to the stub of a 45-degree conversion bend which is half cemented in to the wall, so I can't take out the whole tee...

Any suggestions as how to continue attach the vent pipe other than coring a 22mm pipe through the cap with plenty of silicon and defeating the benefit of the AAV?![/img][/i]

Many thanks!

 

[DaleRCL]

Unscrew the cap, use a hacksaw blade (taken out of the saw) and cut one line through the wall if the access cap but not as far as the wall of the tee. Then use a flat screwdriver to prize it out. Should come out quite easily.

 

[newbuildinstaller]

how much access do you have?

In the past I have managed to:

a) cut the lip off the access cap (between the tee and cap)
b) melt a score in the cap threads from bottom to top (heated screwdriver)
c) CAREFULLY hammer a small sharp flat heat in between the cap threads and the tee's socket. Try to prize the cap's threads inward away from the socket

Not easy but doable!!!

 

[BHI]

Perfect, thanks guys - I'll try tomorrow... Hopefully he went sparse on the solvent cement!

 

[newbuildinstaller]

http://www.screwfix.com/p/flexi-waste-straight-coupling-38-45mm/81383

or an easier way would be to remove the cap and fit this over the tees socket and onto what ever you want to connect to

 

[BHI]

Now that's an interesting solution... Thinking outside of the box / pipe!

 

[BHI]

Cut the lip off the access cap as suggested, but even with numerous vertical grooves cut in to the inner wall, couldn't extract the actual insert since it's properly cemented in.

So plan B... Rather than forking out a tenner for the flexible coupling, I'm going to use bits of what I've already got to mimic the same concept. Will file the current fitting completely flush and solvent weld a reducer directly on to the top. Obviously this wouldn't be particularly strong, so will use a short length of spare 50mm pipe as an (albeit slightly loose-fitting) coupler over the join. And apply plenty of cement...

For practicality, the 50mm sheath will be cemented to the 135-tee first , before cementing the reducer inside the 50mm top section, so I can make sure that all of the solvent welds are good! Doesn't need to be water-tight, but it does need to be air-tight!

Not an ideal solution, but nor was the original problem...

Many thanks for the inspiration!