breplum
I am a plbg contr. but have only done this at home spa, with mixed results. First, the style of couplings you describe come from a few mfrs. One type called Cremco is a semi-rigid plastic with two ss bands, the other typ. by Mission is neoprene with full s.s. sheild, Fernco is all rubber.
Problems come from long term deformation of the plastic. My system runs at over 25 psi. With Cremco, within the first 6 months I did have a blowout, now 3 years later it has been fine. I would only recommend these be used in an exposed location, not too close to the heater (2.5′) and monitor as usual.
