Accuracy of Wet Dial Vane Type Water Meter

Abstract

Because of vane type water meters are simple in construction and cheaper in price than volumetric type water meters, so they are used in many countries, in Asia, especially in Taiwan, Japan, and Korea. But there are some faults in this type meters. The fist of that it the vane doesn't turn at low flow (about under 20 L/hr), second, the meters don't indicate accurate flow quantities under about 150L/hr flow velocities, (only indicates about 10-20% of accual flow quantities). It means the meter accuray is only 10-20% at low flow rate. To improve the character of this kind water meters, we manufactured the special water meters which insert the ruby in the pivot bearing of vane spindle (Type 13-C and Type 20-C, 13 indicate 13mm diameter watermeter, 20 indicate 20mm diameter water meter). Type 13-A, Type 20-A; --old type water meter, all gears are manufactured by branze or phospher branze. Type 13-A, Type 20-B; --newer type water meter, all gears are manufactured by Derlin or Cycloc (plastic). Type 13-C, Type 20-C; --the type of newest type which are manufactured by us (insert ruby in pivot bearing). The experimental results indicate, the character of type C meters are best among three type, can inprove accuracy about 50-60% than type B and C.