How to choose the flange of the valve, novices ask what is the difference between the valve and the

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

According to the standard, pressure, size of the specification to choose, pay attention to whether the pipe material is compatible at the same time, like some plastic pipes must be compatible with the flange of the material.

According to the diameter of the valve and the pressure level and standard, the matching flange is selected.

The valve is a pipeline accessory that controls the flow or stop, flow direction and flow speed of the medium in the pipeline;

A flange is an interconnected part between shafts and can be used for connections between pipes and accessories.

Flanges can be used as a connection between the valve and the pipe.

The difference between valve and flange can be explained in detail below:

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Valves are pipeline accessories used to open and close pipelines, control flow direction, regulate and control the parameters (temperature, pressure and flow) of the conveyed medium. According to its function, it can be divided into shut-off valves, check valves, regulating valves, etc.

Valves are control components in fluid transportation systems, which have the functions of shut-off, regulation, diversion, prevention of backflow, pressure stabilization, diversion or overflow pressure relief. Valves for fluid control systems range from the simplest shut-off valves to the most complex valves used in automated control systems.

Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, slurries, oils, liquid metals and radioactive media. Valves are also divided into cast iron valves, cast steel valves, stainless steel valves, etc.), chrome-molybdenum steel valves, chrome-molybdenum vanadium steel valves, duplex steel valves, plastic valves, non-standard customized valves, etc.

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Flange (tool part).

Flange, also known as flange disc or flange. A flange is a part that is connected to each other between shafts and is used for the connection between pipe ends; There are also flanges used on the inlet and outlet of the equipment, which are used for the connection between two equipment, such as the reducer flange. Flange connection or flange joint refers to the detachable connection of flanges, gaskets and bolts connected to each other as a set of combined sealing structures.

Pipe flange refers to the flange used for piping in piping installation, and used in equipment refers to the inlet and outlet flange of equipment. There are holes in the flanges, and the bolts make the two flanges close together. The flanges are sealed with gaskets.

Flange sub-threaded connection (threaded connection) flange, welded flange and clip flange. The flanges are used in pairs, and the wire flange can be used for low-pressure pipes, and the welded flange is used for pressures above four kilograms. A gasket is added between the two flanges and then bolted.

The flange thickness is different for different pressures, and the bolts they use are also different. When the pump and valve are connected to the pipeline, the parts of these equipment and equipment are also made into corresponding flange shapes, also known as flange connections. All the connecting parts that are bolted around the periphery of the two planes and closed at the same time are generally called "flanges", such as the connection of ventilation ducts, this kind of parts can be called "flange parts".

However, this connection is only a part of the equipment, such as the connection between the flange and the pump, so it is not good to call the pump "flange parts". Relatively small ones, such as valves, can be called "flange parts".

The difference between a valve and a flange is:

Valve: can stop the flow of liquids at will. Flange: It is a pipe connection part.

This problem mainly refers to the two forms of butterfly valves, the clamp type and the flange type

The clamp-type butterfly valve (the valve itself cannot be flanged) is to connect the valve between the two pipe flanges with a stud bolt; The clamp-on butterfly valve has a simple structure, small size and light weight, and is composed of only a few parts. Moreover, it only needs to rotate 90° to quickly open and close, which is easy to operate, and the valve has good fluid control characteristics. The picture above below is the manual butterfly valve, and the picture below is the electric butterfly valve

<> flanged butterfly valve is a valve with a flange, and the upper two ends of the valve are connected to the pipe flange with bolts. The sealing surface is wear-resistant, so that the messy section has a long service life. The structure is unique, the operation is flexible, labor-saving, convenient, and not affected by the high and low pressure of the medium.

The picture below shows the manual flanged butterfly valve, and the following picture shows the electric flanged butterfly valve

<>, the specifications of the clamp type and the flange type are the same, but the flange bolts of the clamp butterfly valve are relatively long, and the length is "2 times the flange thickness + valve thickness + 2 nuts thickness", and the clamp valve itself cannot be flanged; As long as the bolts and nuts are disassembled, then the pipes at both ends of the valve will not work properly.

The bolt with the flange type is relatively short, and the length is "2 times the thickness of the flange + 2 nuts", that is, the flange of the valve body and the flange on the pipeline are paired, connected by bolts, and the nut is locked; When the flange bolt nut at one end is removed, it does not affect the normal operation of the pipe at the other end.

The national standard flange standard was jointly issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and the Standardization Administration of the People's Republic of China on 2011-01-10, and was implemented from 2011-10-01.

GB T 9112 9124-2010 includes a total of the following 13 standards:

Replaced the national standard GB T9112-2000; GB T10745-1989 standard.

GB T 9112-2010 Steel Pipe Flange Type and Parameters.

GB T 9113-2010 Integral Steel Pipe Flange.

GB T 9114-2010 Rebar pipe flange with neck.

GB T 9115-2010 Butt Welded Steel Pipe Flange.

GB T 9116-2010 Flat welded steel pipe flange with neck.

GB T 9117-2010 Socket welded steel pipe flange with neck.

GB T 9118-2010 Butt Welded Ring Loose Sleeve Steel Pipe Flange with Neck.

GB T 9119-2010 Plate type flat welded steel pipe flange.

GB T 9120-2010 Butt Welded Ring Plate Type Loose Sleeve Steel Pipe Flange.

GB T 9121-2010 Flat Welded Ring Plate Type Loose Sleeve Steel Pipe Flange.

GB T 9122-2010 Flanging ring plate type loose sleeve steel pipe flange.

GB T 9123-2010 Steel Pipe Flange Cap.

GB T 9124-2010 Steel Pipe Flange.

Technical conditions. The pressure marks specified in this standard are divided into PN marks and class marks.

PN is marked with 12 pressure classes.

They are:; pn6;pn10;pn16;pn25;pn40;pn63;pn100;pn160;pn250;pn320;pn400

The class is marked with 6 pressure classes.

They are: class 150; class 300;class 600;class 900;class 1500;class 2500

Another meaning of the national standard flange is: the flange produced in accordance with the size and tolerance range required by the national standard, which is different from the flange that is not produced according to the standard size, also known as the second standard flange (some people call the non-standard flange is incorrect), usually some unscrupulous businesses will reduce the thickness of the flange and the outer diameter of the two sizes to achieve the purpose of saving materials, as well as the processing of flanges with scrap steel or scrap steel, usually this steel is a waste material whose chemical composition and mechanical properties are not up to standard, and even more with black steel mills to produce flanges. The steelmaking technology used in this kind of private steelmaking is outdated, and the mechanical properties and welding properties cannot be guaranteed, and it may not be able to be welded with the steel pipe when used, or the steel itself will have cracks and pores, etc., and it will leak water after welding. Therefore, when buying flanges, try to choose national standard flanges.

If the funds are limited, in the case of choosing the second standard flange, you must carefully observe and measure the size of the flange to avoid being deceived.

Valve flange connection:

1.First of all, it is necessary to choose flange standards, national standards, chemical standards, mechanical standards, ship standards, non-standards, etc.;

2.Then there is the pressure rating of the flange (MPa), etc.;

3.The second is the flange type and sealing surface form, (butt welding, flat welding, plug welding) bump flange, concave and convex flange, tenon and groove flange, etc.;

4.Flange connection size, flange outer circle diameter, bolt hole center distance, bolt hole diameter, flange thickness, boss height, etc.

1.Whether the material of the body, plate and shaft meets your requirements.

2.Design pressure.

3.In particular, it is necessary to pay attention to whether the hanging glue of the valve body adheres well to the valve body. and whether the rubber meets your requirements, especially the glue content and hardness.

4.Whether the sealing of the shaft head, the sealing of the valve plate and the rubber hanging surface meet the design pressure. Be careful to carry out shell and seal tests.

5.Whether the fit between the valve plate and the sealing surface is appropriate, if it is too large, it will increase the torque (this should be considered in the mating transmission mode) and reduce the service life. Too small will cause shaft head leakage and plate surface leakage.

6.Attention should be paid to the standard of the side flange, which should be consistent with the flange standard of the pipe design.

First of all, we must look at the pressure, we must choose a larger pressure, otherwise there will be problems, and the caliber should be consistent with the caliber of the valve, and the center distance should be appropriate, otherwise it will not be installed.

It is necessary to pay attention to the standard of the flange, and the flange standard and flange face must be clarified.

When using a grooved flange to install a valve:

1. a set of grooved flange sub-orders;

2. The valve shall be applied to the relevant valve sub-items in the process pipeline, and shall not be applied to the sub-items in the water supply and drainage installation.

3. The clamp does not cover the sub-item, only the main material cost.

When the groove is connected, the valve can be grooved valve (but it is difficult to generalize and procure), and it is generally better to use flange valve, which can be equipped with a grooved flange without neck and short diameter. If the grooved valve is used, it needs to be equipped with 2 clamps (rigid joints), and a flanged valve needs several bolts depending on the diameter and pressure level of the pipe.

Bill of Materials. Budgeting for expenses.

The flange should match the pressure level of the valve, so that the flange size will be the same. There is also the need to pay attention to the direction of the Flangcomde.

Of course, according to the two parameters of the diameter and pressure of the valve, in accordance with the sealing surface form of the valve, and the connection method with the pipeline, and then check the standard on the line, the specific data standards are given, the sealing form of the valve: plane, protruding surface, concave and convex surface, tenon and groove surface, ring connection surface, etc.

Flange connection forms include, butt welding, socket welding, flat welding, etc., and more.

Specifications Pressure , flange sealing surface form.

What valve, pressure, model,

Bolts for valves: fully threaded studs, loose joint bolts, hexagon socket bolts, hex bolts.

1. Calculate the liter Kaishen formula:

Valve flange thickness + anti-flange thickness + gasket thickness + nut thickness * 2 + 6 * pitch;

Sun Xun valve flange thickness noisy loss + anti-flange thickness + gasket thickness + nut thickness + 3 * pitch.

2. Check the "Valve Bolt Correspondence Table".

Flange valves are mainly used with Li traces HG T20634, HG T20613, GB T901, GB T6170, GB T5782, GB T6170 and so on.