The necessity of pressure relief valves and control valves in steam pipelines

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When steam is discharged from the boiler at high pressure and then sent to various points where it is used, pressure reduction is generally applied. Commonly used steam pressure reduction valves include: YG43H/Y high-sensitivity steam pressure reduction valves, Y43H pilot-piston type steam pressure reduction valves, YD43H ultra-large diaphragm steam pressure reduction valves, ZZYP self-acting steam pressure reduction valves, ZZYP and ZZYM types of self-acting electronically controlled steam regulating valves, ZAZP and ZAZM electric precision single-seat steam regulating valves, ZDLP and ZDLM types of electronic electric sleeve steam regulating valves, CV3000-HTS single-seat steam regulating valves, etc. So why is it necessary to reduce the pressure of steam? 1. Boilers typically produce high-pressure steam, which helps to reduce the size of the boiler, minimize the formation of wet steam, increase the dryness of the steam, and enable its transmission over long distances. 2. It is caused by changes in the density of steam: at high pressures, the density of steam is higher. Therefore, the same-sized pipes can transport high-pressure steam more effectively than low-pressure steam. Using high-pressure steam transmission allows for smaller pipe dimensions, thereby saving costs. 3. Condensation occurs when steam is in use; by reducing the pressure of the steam, the pressure of the condensate water is lowered, which prevents flash vapor from being generated during the discharge of the condensate water and thus avoids losses. The energy loss associated with discharging condensate water at low pressure is minimal. 4. Since the temperature and pressure of saturated steam are related to each other, pressure regulators are installed in both sterilization processes and paper drying machine systems to control pressure, thereby regulating the temperature of the process equipment. 5. Process equipment has its own design pressure; when the steam pressure supplied exceeds the requirements of the process system, pressure reduction is necessary. In some systems, low-pressure flash steam is generated using high-pressure condensate to achieve energy savings. When the amount of vapor generated is insufficient, a pressure relief valve is needed to produce low-pressure steam as a supplement. 6. It can reduce the steam load on the boiler, as steam has a higher heat enthalpy at low pressures. The enthalpy value is 1839 kJ/kg at 2.5 MPa, and 2014 kJ/kg at 1.0 MPa. Therefore, low-pressure steam is more suitable for equipment use.