The main performance indicators of safety valves include:

1. Security. When the valve leaves the factory, strength and sealing tests were conducted according to relevant standards to ensure that the mechanical performance of the valve meets the requirements of the standards.

2. Sensitivity. The takeoff pressure and reseating pressure of the valve are within the range of standards and user requirements, with accurate takeoff pressure, rapid takeoff, and stable reseating pressure.

3. Sealing performance. After the valve is reseated, the sealing performance is excellent and there is no leakage.

4. Safety valves with emission requirements shall have mechanical characteristics that meet the standard requirements for emission after valve takeoff. The sealing performance and other performance of the valve shall remain stable and unchanged.

1、 General principles:

1. Hot water boilers generally use non enclosed micro opening safety valves with wrenches.

2. Steam boilers or steam pipelines generally use non enclosed fully open safety valves with wrenches.

3. Non compressible media such as water are generally used with closed micro opening safety valves or safety relief valves.

4. High pressure water supply equipment generally uses closed full open safety valves, such as high-pressure water heaters, heat exchangers, etc.

5. Spring type safety valves are generally used for compressibility media such as gas, such as gas storage tanks, gas pipelines, etc. If the working medium of the container is toxic, flammable, and explosive, a closed safety valve should be selected.

6. E-class steam boilers generally use static weight safety valves.

7. Large caliber, large displacement, and high-pressure systems generally use pulse type safety valves, such as temperature and pressure reducing devices, power plant boilers, etc.

8. Train tankers, car tankers, storage tanks, etc. that transport liquefied gas generally use built-in safety valves.

9. The top of the oil tank usually uses a hydraulic safety valve, which needs to be used in conjunction with a breathing valve.

10. Pilot operated safety valves are generally used for underground drainage or natural pipeline.

2、 Parameter determination:

1. Determination of working pressure level (pressure level)

The working pressure level of a spring refers to the allowable working pressure range of a certain spring. Within this pressure range, the opening pressure (i.e. set pressure) of the safety valve can be adjusted by changing the pre compression amount of the spring. Safety valves with the same nominal pressure can be divided into various working pressure levels according to the spring design requirements.

When selecting a safety valve, the working pressure level of the safety valve should be determined based on the required opening pressure value.

2. Determination of nominal diameter

The nominal diameter of the safety valve should be determined based on the necessary emissions of the protected system. The rated displacement of the safety valve used should be greater than and as close as possible to the necessary discharge capacity. The necessary emissions of the protected system refer to the mass of media that must be eliminated to prevent excessive overpressure in the event of abnormal overpressure in the system. It is determined by factors such as the working conditions, capacity, and possible causes of overpressure of the system or equipment.

3. Material determination

The selection of material for safety valves should consider various factors such as the working temperature, working pressure, medium performance, and material craftsmanship, economy, etc. of the medium. In general, users can choose based on the working temperature, pressure range, and representative types of media used for different types of safety valves listed in the safety valve samples provided by the production unit. When there are special requirements for materials, they can be resolved through negotiation with the production unit when placing an order.

3、 General Safety Valve Ordering Instructions

Ordering a general safety valve should indicate the following:

1. The model, nominal diameter, and nominal pressure of the safety valve.

2. The working pressure level or opening pressure (set pressure) value of the safety valve.

3. Valve body material and sealing surface material.