Main body has 22mm Compression on both ends but you have included in the box 2 reducers to take it down to 15mm. FITTING SIZE: 22mm and 15mm (USING REDUCING INSERTS SUPPLIED). PRESSURE REDUCING VALVES ARE INSTALLED IN WATER SYSTEMS TO REDUCE AND STABILISE INLET PRESSURES FROM MAINS WATER SUPPLIES OR BOOSTED WATER SYSTEMS.
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