I picked up a Dream 8kW pool / spa heat pump which came without any fittings for the water in/out. The unit looks like this:
The previous owner used a rubber coupling like this for his pond.
I'm looking to connect this pump to 2" piping for a hot tub, and I'm concerned at the longevity and use case for a part with higher pressure pumps and hot tub chemicals.
The pump has male threaded connections that measure 65mm OD, with a 57mm ID. There's a lip that takes the OD down further but I was unable to measure the ID of that.
The ID makes it between a 1.5" pipe and a 2" pipe so I'm not sure I'll get a snug fit there by inserting a pipe. There may be some sort of 'tailpiece' that comes with the fitting too that I'm not considering.
I have contacted a few spa, pool and pvc pipe specialists who have not heard of this type of fixing before.
Could someone advise if I'm missing any connection combinations here? I could try 3D printing a part but I would have the same concerns with perishing over time.