Vortex flowmeter velocity

The key is that if you’re not specific, I can’t be specific either.

What if I send you a picture to show you?

Hydrogen has a flow rate limit, which is around 15 m/s. It is not recommended to use vortex flow meters for measuring hydrogen, as these devices require a minimum flow rate for gases. Given hydrogen’s low density, it is advisable to use thermal mass flow meters. Feel free to ask for more details

Our country’s standard specifies that the hydrogen flow rate should be kept below 15 m/s. But this makes it difficult to select a flow meter, as there are hardly any meters that can be used. In practice, proper grounding is ensured, and hydrogen flow speeds of 40–50 m/s are quite common. The European standard is that the hydrogen flow velocity should not exceed 1/3 the speed of sound.

In the design of hydrogen pipelines, the flow rate is controlled at 8 m/s; however, this flow rate varies depending on the material of the pipeline. Referring to the specifications for hydrogen stations, there are an economic flow rate and a safety flow rate for gases, and for flammable gases, the safety flow rate should be the focus. Hydrogen has characteristics such as a low ignition energy, a wide range of flammability and explosibility limits when mixed with air or oxygen, and a fast combustion rate; therefore, special attention must be paid to combustion and explosion risks during its production and use. Hydrogen mixed with air or oxygen to form a flammable mixture within the explosive range, combined with an ignition source, are the two basic conditions for combustion and explosion. To this end, combustible materials should be properly managed to prevent hydrogen leaks, escapes, and accumulation, while paying attention to the sealing of the system, suppressing the formation of explosive mixtures, and monitoring it. At the same time, fire sources must be properly managed. Sources of ignition fall into two categories: spontaneous combustion and external ignition. The formation and properties of the fire source are shown in Table 6. Hydrogen flows within the pipes; when the flow velocity is high, the friction with the pipe walls increases. Especially when the pipes contain rust particles, static electricity sparks are generated. According to NASA’s statistics on the 96 hydrogen-related accidents, 62% were fires that occurred after hydrogen was released into the atmosphere and mixed with air, while 17.2% were fires caused by static electricity. For many years, the flow rate has been controlled at 8 m/s in hydrogen pipeline design. Before the revision of this standard, the maximum flow rate of hydrogen in carbon steel pipes was specified as 8 m/s when the pressure was greater than 1.6 MPa, and 12 m/s for pressures between 0.1 and 1.6 MPa ； The speed for stainless steel pipes is 15 m/s. During the implementation of the original standards, some organizations asked questions and provided information regarding flow rates that exceeded the specified maximum values; for example, Yanzhi Petrochemical BASF Company stated that the hydrogen flow rate in its related petrochemical facilities was kept below 20 m/s. In recent years, with the introduction of technologies and equipment as well as technical exchanges in our country, many organizations have actually exceeded the flow rates specified in the original standards.

The hydrogen gas flow rate should be kept below 15 m/s; please use the explosion-proof SHQL series thermal mass flow meters

Have you asked Einstein about using hydrogen at such a high flow rate?

How many hydrogen meters have you sold? Still asking me here if I’ve asked Einstein? If you have the time, consult those who know Emerson; it’s better to learn more rather than argue with others*. If thermal methods work well, there’s no need for such strenuous sales efforts; mass flow meters can be completely replaced by them.