Why are there pressure fluctuations after the steam pressure relief valve?
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It’s a steam pressure reducing valve; the pressure before the valve is 9 Kg, and the pressure after the valve is supposed to be controlled at 6 Kg. However, in reality the pressure fluctuates significantly, generally ranging between 4 and 6 Kg. What is the reason for this? Is it a problem with the pressure reducing valve? The steam usage behind the valve is relatively even, with no instances of sudden heavy use of steam. I would appreciate some guidance from those who are in charge of the valve area.
Is yours electric or pneumatic? It’s still a self-acting type; if it is self-acting, then the spring wasn’t chosen properly! ! I think!
The poster should be using a self-priming type, I guess. There are several reasons for this: 1. Determine whether impurities are causing the pilot valve to get clogged? 2. Check if the filter is clogged? 3. Check whether the piston valve is damaged? 4. Is the pressure outlet pipe of the valve blocked? If there is any shortage, please make up for it.
This post was last edited by diwu0205 on 2011-1-25 at 17:07. It’s possible that impurities have entered the pressure relief valve, or that there is too much condensation water in the system; it is recommended to carry out inspections to determine the cause.
Steam pressure relief valves also come in several types: self-acting, pilot-operated, and directly acting. Spiessag uses pilot-operated valves, while domestic companies generally use directly acting valves; ARI in Germany employs self-acting pressure relief valves. If the steam pressure and flow rate before the valve change, in the case of a direct-acting pressure regulator, the pressure after the valve will definitely change as well. Both pilot-operated and self-acting pressure regulators have tubes that draw feedback pressure from the downstream pipeline, allowing changes in downstream pressure to be fed back to the regulator’s spring; as a result, their pressure reduction performance is better than that of directly acting regulators. If the steam consumption and upstream steam pressure remain stable, the downstream pressure generally does not fluctuate. In cases like the one mentioned by the original poster, I also believe it is caused by an inappropriate selection of the spring during the selection or adjustment of the pressure relief valve.
I. First, it is necessary to determine whether the steam pressure reducing valve used by the poster is domestic or imported II. Is it pilot-operated or actuated directly? III. Piston-type or diaphragm-type? If higher precision is required, it is recommended to consider pilot-diaphragm steam pressure regulators; the South Korean Simat series 2002: http://www.ou-ray.com/cn/series2002.html