Dynamic Series I/II RDC-25 RTL/RCF-25, IV-DFM Compatible Filter Cartridge letter-size_6 Inch these types of valves are

these types of valves are designed to allow excess pressure to escape

This is a Pentair Clear Sight Glass Nipple for HiFlow 2 Inch Valves Models 261049

Separation Tanks Model SEP48

The stainless steel rims last much longer

Dynamic Series I/II RDC-25 RTL/RCF-25, IV-DFM Compatible Filter Cartridge letter-size_6 Inch these types of valves areThe Hurricane HF4326 01 Advanced Cartridge Filter is compatible with Dynamic Series I RDC 25, I RDC 25S, Dynamic Series II and II RTL RCF 25, Dynamic Series IV DFM, DFML, Waterway 25 In Line, and other compatible models. It is identical to Unicel C 4326, Pleatco PRB25, and Filbur FC 2375 filter cartridges. The original manufacturer's names and part numbers are for reference only. Hurricane's advanced point bond filter media has tighter filtration