Cooling System Flusher 1/4" BSPP - 142185-000 Water with compressed air to increase the efficiency of cooling system flushing. Compressed air increases the water pressure compared to that delivered by the mains water. Equipped with a 13mm diameter 1/2" connection for water couplings. Use of a hose connector with a control valve is recommended - flow can then be adjusted or switched off without a trip to the tap.