HOW TO SELECT FLANGE?

Flange is a part connected between shaft and shaft, which is used to connect pipe ends. Flange is also used in the import and export of equipment, which is used to connect two equipment, such as reducer flange. Flange connection or flange joint refers to the removable connection of flange, gasket and bolt as a group of combined sealing structures. Pipeline flange refers to the flange used in piping equipment, and the flange used in equipment refers to the import and export flange of equipment. There are holes in the flange, and the bolts connect the flanges tightly. The flanges are sealed with gaskets. Flange is divided into threaded connection (screw connection) flange, welding flange and clamp flange. Flanges are used in pairs. Wire-jointed flanges can be used in low-pressure pipelines, and welding flanges can be used under pressure of more than four kilograms. A gasket is added between the two flanges and then bolted. The thickness of flanges under different pressures is different, and the bolts they use are also different.

Method of distinguishing quality of flange

1. Opening and closing force and moment: This parameter refers to the force or moment that must be applied when the valve is opened or closed.

2. Valve resistance: When the medium flows through the valve, there will be pressure loss (pressure difference between before and after the valve), that is, the valve has certain resistance to the flow of the medium, and the medium will consume a certain amount of energy to overcome the resistance of the valve.

3. Service life: It indicates the durability of the valve, is an important performance index of the valve, and has great economic significance;

4. Sealing performance: The sealing performance of the valve refers to the ability of the sealing parts of the valve to prevent medium leakage, which is the most important technical performance index of the valve.

5. Opening and closing speed: Opening and closing speed is expressed by the time it takes for the valve to complete an opening or closing action.

6. Operation sensitivity and reliability: This refers to the sensitivity of the valve to the change of medium parameters and corresponding response;

7. Strength performance: The strength performance of the valve refers to the ability of the valve to withstand medium pressure.

 

How to Select and Use Flanges

1. The properties of conveying medium, general medium, special medium, toxic medium, inflammable and explosive medium;

2. The nominal pressure PN of flange is determined according to the parameters of medium, working pressure and working temperature, and when the medium is determined, according to the working temperature and working pressure of medium.

3. Determine the connection mode of flange and pipe and the form of sealing surface according to the use place and connection condition.

4. Determine the flange specification according to the connecting object.

Of course, in the continuous production of modern industry, flange will inevitably leak due to medium corrosion, erosion, temperature, pressure, vibration and other factors. The leakage of flange is easily caused by the errors in the dimension of sealing surface, aging of sealing elements and improper installation and fastening. If the flange leakage problem can not be treated in time, the leakage will expand rapidly under the erosion of the medium, resulting in material loss, production environment damage, leading to shutdown of enterprises, resulting in huge economic losses. If it is toxic, harmful, flammable and explosive medium leakage, it may also cause personnel poisoning, fire and explosion and other major accidents. The traditional methods to solve flange leakage are replacing sealing elements, smearing sealant or replacing flanges and pipes. However, this method has great limitations, and some of the leakage is limited by the requirements of working environment safety, so it can not be solved on site. Polymer composites can be used to plug the leakage in situ, and the relatively mature system of Youshilan can be used. It is an ideal method, especially in flammable and explosive occasions, which shows its unique advantages. Polymer composite technology construction process is simple, safe, and low cost, can solve most of the problems of flange leakage for enterprises, eliminate potential safety hazards, and save more maintenance costs for enterprises.