in diameter and branch pipe 4 brings water to the 1200 mm diameter tank 6 through a butterfly valve 8 past a flow meter 10 referring now to fig2 and 3 the regulator valve 12 is bolted to the end of the branch pipe 4 and discharges into the tank the valve body stem 14 is a t shaped pipe of 320 mm diameter the body being 510 mm long and the valve body stem 14 terminating in a connector ring 16 with bolt holes 18 for connection to the end of the branch pipe 4 both the body 20 and the valve member 22 fig4 are made of stainless steel water enters the regulator valve 12 via the valve body stem 14 and discharges through the open ends of the body 20 the flow through the valve is controlled by the valve member 22 which is a sleeve of the same length as the valve body namely 510 mm referring now to fig2 the circumferential gap 24 is bridged by a trio of bearing strips 26 made of a slippery polymer and attached to the edge of the valve member by stainless steel fasteners not shown the strips are spaced at 120 degrees enabling the member to rotate in the body with minimum friction referring now to fig4 the crown of the valve member 22 has a cutout 28 with a straight edge 30 and tapered edges 32 extending over about 90 degrees of the circumference of the member the cutout 28 lies in register with.