During the operation of boilers, safety valves are the core components ensuring safety. Han Yu Boiler strictly follows the standards and presents to you the key technical requirements.
I. Quantity and Type Adaptation For boilers with a rated evaporation capacity of less than 0.5 t/h, at least one safety valve should be installed; for those with a rated evaporation capacity of more than 0.5 t/h, at least two safety valves should be installed except for the economizer. Safety valves are required at specific key parts, such as the outlet of the economizer, and behind equipment such as atmospheric thermal deaerators. For boilers with a rated pressure of less than 0.10 Mpa (1 kgf/cm²), static weight type or water sealing devices should be adopted. The inner diameter of the water sealing pipe should not be less than 25 mm and there should be no valve. Anti-freezing measures should be taken.
II. Installation and Safety Device Specifications Safety valves should be installed vertically at the highest position of the drum (or header) for easy maintenance, inspection, and the ability to hear the discharge sound. There should be no steam extraction pipe and valve between the safety valve and the boiler (header). Different types of safety valves have corresponding safety devices. For example, lever-type ones prevent the counterweight from moving, spring-type ones prevent random twisting, and safety valves controlled by compressed air have reliable air sources and power supplies.
III. Specifications and Steam Discharge Capacity Standards When multiple safety valves share a short pipe base, the cross-sectional area of the short pipe passage should be 1.25 times larger than the total steam discharge area of the safety valves. For boilers with a working pressure of less than or equal to 3.9 Mpa (39 kgf/cm²), the inner diameter at the bottom of the safety valve should not be less than 25 mm; for those with a working pressure greater than this, the inner diameter should not be less than 20 mm. The total steam discharge capacity of the safety valve exceeds the maximum continuous evaporation capacity of the boiler to ensure the increase in steam pressure and the maximum pressure are within the specified range. The steam discharge capacity and cross-sectional area of safety valves for each component also have standards.
IV. Steam Discharge Pipe and Maintenance Key Points Safety valves are equipped with steam discharge pipes with an area of at least twice the total area of the safety valves. A drain pipe is connected below to a safe location. Neither pipe has valves. If the steam discharge sound is not easily heard, a signal device should be installed. The steam discharge pipe of the safety valve of the economizer is also set up in the same way. Regular steam or water discharge tests should be conducted on the safety valve. Safety valves of the drum and superheater are calibrated as required, and the opening pressure of the safety valve of the economizer is 1.1 times the working pressure. The discharge pipe of special boilers is connected to a condensate recovery device. When installing lever-type safety valves, the valve flap lever should be vertical, and the flange bolts should be evenly tightened. After calibration, the safety valve should be locked or lead-sealed, and the results should be entered into the technical file.
Han Yu Boiler strictly adheres to the technical specifications of safety valves to ensure the safe operation of boilers. For more boiler knowledge, welcome to visit the official website of Han Yu Boiler at https://www.hanyuboiler.com/ and stay tuned.
