Pipe size describes a connection
Line size tells you the required connection dimensions. It does not establish that a meter covers the actual flow range accurately. Pipes of the same diameter may carry very different flows, and one application may justify comparing several measuring-tube sizes. Physical fit alone is insufficient evidence of measurement suitability.
Define the measurement task first
Batch control, continuous monitoring, energy analysis and commercial measurement have different needs. Establish the required quantity, allowable error, response and normal operating range before comparing instruments. Commercial measurement may also involve the complete measuring system and local requirements; a meter's specifications cannot replace those checks.
- State whether you need mass flow, actual volume flow or standard volume flow.
- Provide minimum, normal and maximum flow, including how long each occurs.
Assess process conditions and consequences
Record composition, fluid state, temperature and pressure range, viscosity, gas or solids content, wetted materials and available space. Compare pressure loss at the required flow with the process allowance. Low-flow performance, connection ratings, cleaning requirements and communications may also change the selection.
Keep the decision reviewable
Compare each candidate's usable flow range, expected pressure loss, materials, installation restrictions and unresolved questions in one worksheet. Obtain missing flow or fluid information rather than estimating from pipe diameter. Manufacturer curves, calculations and approval scope must relate to the exact model and configuration.
