... titanium tube 3. Compact design 4. R22, R410a,R407c,R134a Heat pump heat exchangers are made of top quality ... PVC-U ,PP-R, stainless steel.They passed 4.5Mpa pressure and leaking testing.Pure titanium Seamless ... PP-R, stainless steelExcellent PVC plasticCompact design with high heat transfer ability.Suitable for R22, R134a, R410a,, R407cWorking ... water/antifreeze 10.5kw Spa pool heat pump heat exchanger