Metal tube float flowmeter

Typical requirements: 5D upstream and 250mm downstream.

Example: Chongqing Chuanyi RFC metal tube float flowmeter explicitly requires a straight pipe section of ≥ 5D at the inlet and ≥ 250mm at the outlet.

Glass tube float flowmeter

Requirement: It is usually similar to metal pipes, but additional attention should be paid to vertical installation (fluid from bottom to top) to avoid bubble adhesion.

Rotary flowmeter (a type of float flowmeter)

Standard: According to the "Code for Construction and Acceptance of Automation Instrumentation Engineering" (GB50093-2013), the recommended length of the upstream straight pipe section is 0-5D, and there are no strict requirements downstream; But in practical engineering, conservative designs of 5D upstream+250mm downstream are often adopted.