Fitting new cylinder

The sides have 28mm male threads
and a sticker on the side "do not use tapered fittings"

Next to all the tanks in B&Q are a load of tapered fittings

so what type of fitting do I use to bring it down to 22mm ?

I've seen a simple flat ended 28mm reducer to 22mm that will do the job
but with no olive, will the cylinder be happy with lots of PTFE tape on the 
thread ?

-- 
Vass
Now: YZF-R1 (for sale)
Then: A100, MBX80, XL125, CB400, FZR600, CBR600Fv, CBR1100xx-x
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