... outside 316L 2,surface oxide-resistant non-pollute stainless steel shell heat pump titanium heat exchanger for swimming poolheat pump ... the hot water temperature to be less than 50degree. heating refrigeration pressure is 0.3Mpa 0.4Mpa,0.63Mpa , ... compressor system. refrigeration is R22 ,R134,R407,R41OA . stainless steel shell titanium heat exchanger Tube typeseamless titanium tube or whorl tubeinside ...