Orifice plate flowmeter straight pipe section requirements are like?

Project Overview

The requirements for the straight pipe section of the orifice flowmeter mainly include the following aspects:

1. Straightness of the straight pipe section:

The straight pipe section before and after the throttling member must be straight , there must be no bend visible to the naked eye.

2. Smoothness of the straight pipe section:

The straight pipe section used to install the throttling component should be smooth. If the straight pipe section is not smooth, the flow coefficient should be multiplied by the roughness correction factor.

3. The length of the straight pipe section:

A sufficiently long straight pipe section is required before and after the throttling member, and its length is in proportion to the form and diameter of the local resistance piece in front of the throttling member β ( β=d/D, d is the hole diameter of the orifice plate).

The length of the straight pipe section between the first resistance piece and the second resistance piece on the upstream side of the throttling piece can be taken as listed in the form of the second resistance piece and β=0.7 (regardless of the actual β value) 1/2 of the value.

When the upstream side of the throttling member is an open space or a large container with a diameter ≥ 2D, the length of the straight pipe between the open space or large container and the throttling member shall not be less than 30D (15D). If there are other local resistance parts between the throttling part and the open space or large container, in addition to the minimum straight pipe length that meets the regulations between the throttling part and the local resistance part, the length from the open space to the throttling part The total length of the straight pipe sections between them shall not be less than 30D (15D).

4. Installation position of DC components:

When DC components are installed in the pipeline, their front end face must be perpendicular to the axis of the pipeline, and the maximum allowable non-verticality shall not exceed ±1°.

In summary, the requirements for the straight pipe section of the orifice flowmeter cover many aspects such as linearity, smoothness, roundness, length, and the installation position of the DC parts. These requirements are designed to ensure that the fluid passes through The flow state of the orifice flow meter is stable and accurate, thereby improving the accuracy and reliability of measurement.