Should first estimates the size of the normally used by the flow and the flow range, and then select the most common flow close to the value of that kind of specifications of the water meter as the preferred.

Because the stability of the water meter work under common flow performance and durability is the best, comply with the design requirements.

If the pipe in water ability leave allowance to the future, is choosing a meter in diameter specifications on the lower leg. Such as the diameter is 200 mm pipe due to lack of current flow