What is the difference between impulse-type safety valves and pulse-type safety valves?

The impulse safety valve, also known as a lever-type safety valve, operates primarily by the force exerted by a lever and weight. However, its large size often limits its range of applications; it is mainly used in power station boilers or steam pressure pipelines. This valve can be used either in combination with other devices or on its own. When the pressure of the medium inside the pressure vessel exceeds the allowable value, the valve disc opens to release the excess steam; when the pressure drops to a certain level, the weight on the lever causes the valve disc to close quickly, ensuring the safe operation of the equipment. Pulse safety valves, also known as spring-loaded safety valves, operate primarily due to the force exerted by a spring. There are two types of spring-loaded safety valves: those with a sealed design and those without a sealed design. For media that are flammable, explosive, or toxic, a sealed design is generally preferred, while for steam or inert gases, an unsealed design can be used. Additionally, there are spring-loaded safety valves equipped with a wrench and those that do not. The main purpose of the wrench is to check the flexibility of the valve disc; it can also be used for manual emergency pressure relief.

"A pulse-type safety valve consists of a main valve and a secondary valve; the pulse action from the secondary valve drives the main valve to operate. It has a complex structure and is typically used only in boilers and pressure vessels that require a large amount of safety discharge. The auxiliary valve is the impulse safety valve installed on the impulse tube. "Right?

The safety devices consist of a pulse safety valve, a main safety valve, a check valve, a throttle valve, a solenoid valve, a pressure controller, and electrical components. The pulse safety valve is a spring-loaded safety valve; the opening pressure of this valve is adjusted by modifying the spring, and it is equipped with solenoids for opening and closing at its upper part. Activate the electromagnet: When the pulse safety valve reaches the set pressure, the electromagnet is activated, causing the impulse safety valve to open quickly ； Function of the shutdown magnet: It can remain unpowered under normal conditions, but when there is leakage at the valve’s sealing surface, power can be supplied continuously to keep the valve sealed. Alternatively, when the mechanical force used to return the valve to its seat is too low, powering the magnet helps to push the valve back into place, thereby maintaining a higher seating pressure. Working principle of the safety valve of the YG-130/9.8-M boiler unit: The safety valve consists of a main safety valve, a pulse safety valve, and connecting pipes. The main safety valve is controlled by a pulse (impulse) safety valve. Under normal conditions, the main safety valve is pressed shut by steam pressure. When the pressure of the fluid inside the boiler exceeds the allowable level, the pulse (impulse) safety valve opens first to allow steam to flow into the area above the piston of the main valve. The pressure of the steam on the piston is sufficient to overcome the force exerted by the spring, thereby opening the main valve and allowing steam to be released to reduce pressure. Once the pressure inside the boiler drops to a certain level, the pulse (impulse) safety valve closes, cutting off the steam supply to the piston of the main valve. The main valve then closes on its own due to the action of the spring and the fluid pressure, while the remaining steam on the piston acts as a buffer, enabling the main valve to close slowly and preventing damage to the valve disc and seat caused by impact. Function of the safety valve: To release excess steam when the boiler unit is under overpressure, thereby ensuring the safe operation of the equipment.