Brazetek 55 kBTU Titanium Shell and Tube Heat Exchanger for Salt Water Swimming Pool / Solar / Spa / Marine applications Capable of up to 55,000 BTU/hr heat transfer Titanium construction perfect for chlorine or salt water pools and spas Use with solar collectors or conventional boilers for heat supply Tube Side Connections (Straight-Through/Boiler or heat source): 3/4" FNPT Shell Side Connections (Side Outlets/Pool): 1" FNPT