How long should the straight sections before and after the flow meter be?

It depends on the type of flow meter; different requirements apply, but the vast majority of those in the top 10 and bottom 5 meet the requirements.

The length of the straight pipes before and after the flow meter should, first, be in accordance with the length recommended by the flow meter manufacturer. Second, take into account the on-site conditions; third, meet the requirements of the design documents. Sometimes, due to regulatory requirements, the on-site installation space cannot be made available. Second, optimization is carried out in line with the requirements of the flow meter itself. Our company specializes in straight pipes for use before and after flow meters as well as rectifiers. We compare and analyze the installation requirements for process pipelines related to flow meter measurement as specified in foreign standards such as AGA, ISO, and EN, and then develop corresponding installation accessories based on the conditions of pipelines in China and local design requirements. Feel free to consult (Yū Kagawa) if needed.

Flowmeters based on different principles and with different structures have varying requirements regarding the straight pipe section necessary for installation. Some flowmeters do not require such a straight pipe section; for example, mass flowmeters that operate on the Coriolis principle, rotameters, as well as gear-type flowmeters all do not need a straight pipe section. Straight pipe sections are generally required only for flow meters that operate on the differential pressure principle, or for those that need a steady flow of the medium.

Different types of flow meters have different requirements; it is best to refer to the manufacturer’s installation instructions. Throttling devices generally require relatively long straight sections of pipe. For standard orifice plates and similar devices, relevant standards can also be consulted, such as these:

It depends on what type of flow meter it is. If it’s still not enough, add a rectifying disc.

Refer to the operating instructions for the relevant instrument; for normal straight sections before and after, follow the chemical industry standards and specifications

Being in the top ten or the top five is considered a standard requirement; if achieving the top ten isn’t possible, then focus on making it into the top five. If that’s not feasible either, then at least being in the top five is the minimum requirement.

Requirements for straight pipe sections in the installation of various flowmeters MCT intelligent valve positioner

For ordinary flow meters, the top 10 and bottom 5 are sufficient; if standards are applied, I believe that approach is not appropriate. Technology is advancing; I think it’s sufficient to look at what the equipment manufacturers require. In the past, it was enough to have the top five models in terms of vortex flow meters, but I think those earlier or later models are now outdated

Depending on the type of flow meter, mass flow meters do not require a straight pipe section