Potterton Hydraulic 3 Bar Pressure Relief Safety Valve. Potterton Performa 24 (GC No. 47-393-06). Potterton Performa 28 (GC No. 47-393-07). Potterton Performa 28i (GC No. 47-393-08). Potterton Performa System 12E (GC No. 41-590-88).
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