Installation instructions and steps of wafer butterfly valve
What is wafer butterfly valve？
The butterfly plate of the wafer butterfly valve is installed in the diameter direction of the pipe. In the cylindrical channel of butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0 ° and 90 ° to regulate the flow. When the butterfly plate is rotated to 90 °, the valve reaches the maximum opening.
The wafer butterfly valve is simple in structure, small in size and light in weight, and only consists of a few parts. Moreover, the valve can be opened and closed quickly by only 90 ° rotation, which is easy to operate. At the same time, the valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has good flow control characteristics. Butterfly valve has elastic soft seal and metal seal. Elastic soft sealing valve, sealing ring can be inlaid on the valve body or attached to the periphery of butterfly plate.
The valve with metal seal has longer service life than that with elastic seal, but it is difficult to seal completely. The metal seal can adapt to higher working temperature, while the elastic soft seal has the limitation of temperature.
If butterfly valve is required to be used as flow control, the main thing is to select the correct size and type of valve. The structure principle of butterfly valve is especially suitable for making large diameter valve. This kind of valve should be installed horizontally in the pipeline.
There are two kinds of butterfly valves in common use: wafer butterfly valve and flange type butterfly valve. Wafer butterfly valve is to connect the valve between two pipe flanges with stud bolts. The flange butterfly valve is a valve with flange, and the flange on both ends of the valve is connected to the pipe flange with bolts.
Application of wafer butterfly valve
It is used for gas pipeline in sulfuric acid industry: inlet and outlet of blower in front of furnace, inlet and outlet of relay fan, series connection valve of electric mist eliminator, inlet and outlet of S02 main blower, converter regulation, inlet and outlet of preheater, etc.
In the sulfur burning, conversion and dry absorption section of sulfur burning sulphuric acid system, it is the preferred brand of valve for sulfur based sulfuric acid plant. It is considered as a butterfly valve with good sealing performance, light operation, secondary corrosion, high temperature resistance, convenient operation, flexible operation, safe and reliable use, which has been widely used.
It is also widely used in the pipeline of SO2, steam, air, gas, ammonia, CO2 gas, oil, water, brine, alkali, sea water, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and other media in the chemical, petrochemical, smelting, pharmaceutical, food and other industries.
Structural characteristics of wafer butterfly valve
- ① The unique design of three-way eccentricity makes no friction transmission between sealing faces, thus prolonging the service life of the valve.
- ② Elastic seal is produced by torque.
- ③ The ingenious wedge-shaped design enables the valve to have the function of automatic sealing, with compensation and zero leakage between the sealing surfaces.
- ④ Small size, light weight, light operation, easy installation.
- ⑤ According to the requirements of users, pneumatic and electric devices can be configured to meet the needs of remote control and program control.
- ⑥ The material of replacement parts can be applied to various media and can be used for lining anticorrosion (lining F46, gxpp, Po, etc.).
- ⑦ Continuous structure diversification: clamp, flange, butt welding.
Before installation of wafer butterfly valve:
- 1. Before installation and operation, clean the pipe with air and clean the inner surface with water.
- 2. Carefully check whether the service condition of the valve is consistent with its performance specification; (temperature and pressure)
- 3. Check whether there are impurities in the valve channel and sealing surface, and remove them in time;
- 4. After unpacking, the valve should be installed in time. Do not loosen any fastening screws or nuts on the valve at will;
- 5. Special flange of butterfly valve must be used for wafer type butterfly valve.
- 6. Electric butterfly valve can be installed in any angle of the pipeline, in order to facilitate maintenance, it is recommended not to install upside down.
- 7. During the installation of butterfly valve flange, it must be ensured that the flange face and the sealing rubber are aligned, and the screws are evenly tightened, and the sealing surface must fit completely; if the screw tightening force is not uniform, rubber bulge will block the butterfly plate, or the valve rod will leak due to the sticking of the butterfly plate.
Installation steps of wafer butterfly valve:
The correct installation of wafer butterfly valve is related to the sealing degree of butterfly valve and whether it will leak or not, including the safety in operation under working conditions. Users should understand the installation process.
1. As shown in, place the valve between the two pre installed flanges, paying attention to the alignment of bolt holes.
2. Insert four pairs of bolts and nuts into the flange hole, and tighten the nuts slightly to correct the flatness of flange surface;
3. Fix the flange on the pipe by spot welding;
4. Remove the valve;
5. The flange shall be completely welded and fixed on the pipe;
6. Install the valve after the weld joint is cooled. Ensure that the valve has enough movable space in the flange to prevent the valve from being damaged, and ensure that the valve plate has a certain opening degree;
7. Correct the position of the valve and tighten the four pairs of bolts;
8. Open the valve to ensure that the valve plate can open and close freely, and then slightly open the valve plate;
9. Tighten all nuts evenly across;
10. Make sure that the valve can open and close freely.
- Note: make sure that the valve plate does not touch the pipe.
The installation of the clip on butterfly valve must be placed horizontally before installation, and it must not be bumped at will. After it is drawn to the installation length during the installation, in the field pipeline design, it is not allowed to dismantle the clip type butterfly valve without special permission. This is what we need to know before installation. At the same time, we should also know that the double clip butterfly valve can be installed in any position, but after the installation of the clip on butterfly valve, the butterfly valve needs to be laid along the line. Once the bracket is made, it is strictly forbidden to remove the bracket when using it.
Source: China Valves Manufacturer – Yaang Pipe Industry (www.pipelinedubai.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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