Why do some devices require 2 or 3 safety valves, and what are the installation guidelines?
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Logically, one of them should be able to hold up, as long as the equipment isn’t under excessive pressure, right?
Generally, one or two are installed; I’ve never seen three. These days, many companies with strict requirements install two, especially foreign-funded enterprises. Two are installed because the safety valve needs to be calibrated once a year, and it has to be removed for that.
High-pressure systems or those with a high degree of risk generally are equipped with two safety valves, to prevent accidents that could occur if a safety valve fails to release pressure; in other words, this serves as a double safeguard to increase the safety factor.
I agree with the comment above; the purpose of installing two safety valves is to prevent accidents from occurring in case one of them malfunctions, thereby increasing the safety level of the production system.
Or install an explosion-proof film and a safety valve! In addition to the dual safety valves mentioned above, I believe there is also a mechanism designed to prevent insufficient pressure relief in cases where the safety valve opens only slightly or partially; in such situations, the explosion-proof membrane ruptures to protect the equipment. Replacing the explosion-proof membrane would result in the shutdown of the system. Currently, most systems are equipped with two safety valves, and there is a slight difference in their operating pressures Let’s discuss together!
In some cases, high-volume discharge is required, and the discharge capacity of a single safety valve is insufficient. Some are high-risk devices that require insurance and the installation of dual safety valves. There is also the issue of redesign: it’s necessary to make use of the existing components while simultaneously meeting the new capacity requirements, which means installing an additional one
Some pressure vessels are equipped with two to three safety valves due to differences in the operating pressure of these vessels as well as the types of substances contained within them. For example, if a vessel is used to hold a substance that requires a lower pressure level, then a safety valve with a lower setting is installed; whereas if it is used to hold a different substance that requires a higher pressure level, then a safety valve with a higher setting is used! In some factories, the pressure vessels can be interchanged, so it’s possible to have 2 to 3 safety valves!
Reply to 7# dailonglu7: I’m not entirely in agreement; it’s just one special case! :)
Reply to 7# dailonglu7: As mentioned by the original poster, a stop valve must be installed in front of the safety valve. When switching to different types of raw materials, it is necessary to open the stop valve located in front of the corresponding safety valve, while closing the stop valves of the other safety valves； Doing this is quite troublesome; if you forget or turn the valve in the wrong direction, safety accidents can occur, so be sure to pay attention!
For some particularly important pressure vessels, multiple safety valves are installed as a form of redundant protection.