Is the pressure relief valve irreplaceable?

I’m also a bit confused about this issue. For example, is the pressure reduced by the pressure relief valve or controlled by the rear system? If the rear system keeps releasing pressure or holding it at a high level, then does the pressure relief valve stop functioning once that pressure is reached? Then it’s no longer a stand-alone valve

In my opinion, in rough-and-tumble production process designs, pressure relief valves are usually chosen, such as in the metallurgical industry. For the detailed design in the chemical industry, a self-driven approach seems to be more reliable. As for controlling the flow rate and pressure of fluids, pressure reducing valves, self-acting control valves, pneumatic/electric automatic control valves, as well as various manual valves all possess this pressure reduction function; it’s just that mechanical and automated controls save labor compared to manual methods, or they are more reliable. In the design, the pressure relief valves and other automatic valves installed on the pipelines are equipped, as needed, with manual bypass valve sets to serve as a backup control mechanism in case of valve failures. Safety valves are also provided to prevent overpressure at the rear end. Hehe, a safety valve is also a type of pressure relief valve: lol

Personally, I think it’s not possible. The pressure relief valve I have come across is a cage-type pressure relief valve, used in steam networks, to reduce pressure from 90 kilograms to 40 kilograms. If ball valves or similar types of valves are used instead, I think there will be more wear and tear; they won’t last long. Additionally, their sensitivity to adjustment is relatively poor, which means they cannot meet the requirements of the lower-level piping systems.

Taking pressure control as an example, the accuracy of a self-acting pressure reducing valve is related to its flow range; for instance, with a flow range of 5:1, the pressure control accuracy is 10%. Some products with a controller can achieve 3%. If the downstream users are not strict regarding pressure parameters and the set values remain unchanged, then it is possible to consider using pressure reducing valves, such as a first-stage pressure reduction station for N2. The opening degree of the pressure relief valve changes automatically with the downstream pressure, but the underlying cause of this pressure change is the load level of the downstream users. When the load downstream increases, the pressure behind the valve decreases. The pressure regulator detects this change in pressure and automatically opens the valve wider to increase the pressure and thus \"compensate\" for the increased flow demand. This is something that manual valves cannot do. It functions like a throttle orifice with a variable area; it automatically widens when the flow rate downstream increases. Pressure is superficial; flow is fundamental.