G 3/4 inch Stainless steel 316 Pre-set Safety Valve 4.5 bar (65.27 psi) DN 10 | Tameson.com
Watts 1/2 in. Copper FPT x FPT Pressure Reducing Valve 1/2 LF25AUB-Z3 - The Home Depot
Range - 3, 3.5, 4, 4.5, 4.75, 5, 6, 8 Bar Pressure Relief Valve for Multibloc (new style) TS301 - Unvented Components Europe, Unvented Cylinder System Spares, Spares for Hot Water Systems,