Discharge valve performance and use: easy to operate, open and free, flexible and reliable movement; valve assembly and maintenance simple, reasonable sealing structure, sealing ring replacement convenient and practical. Structure: Mainly consists of valve body, valve disc, seal ring, valve stem, bracket, valve gland, hand wheel, flange, nut, positioning screw and other parts. This type of valve should generally be installed horizontally in the pipeline.
Its main parameters are: nominal diameter DN, discharge valve rated flow coefficient KV, discharge valve nominal pressure and pressure difference, discharge valve body and valve assembly materials, discharge valve flow characteristics, discharge valve applicable temperature , discharge valve power supply voltage and control signals, discharge valve with accessories and so on.
First, the nominal diameter: (nominal diameter), also known as the mean outside diameter (mean outside diameter), said symbol DN, is a common caliber of various pipe and piping accessories. The pipes of the same nominal diameter and the pipeline accessories can be connected with each other and have interchangeability. It is not the actual outer diameter or inner diameter of the pipe, although its value is close to or equal to the inner diameter of the pipe, in order to uniform the pipe and pipe connection dimensions The nominal diameter (also called nominal diameter, nominal diameter) is used. For example, the thickness of welded steel pipe can be divided into thin-walled steel pipe, ordinary steel pipe and thicker steel pipe. Its nominal diameter is not the outside diameter, nor is it the inside diameter, but a nominal size that approximates the inside diameter of a typical steel pipe. Each nominal diameter corresponds to one outer diameter, and its inner diameter value varies with the thickness. The nominal diameter can be expressed in metric mm, or in inch. Pipe fittings are also represented by the nominal diameter, meaning that there is a seam pipe.
2. Nominal pressure: (Nominal pressure), indicating the symbol PN, the maximum allowable working pressure when applied at a certain temperature. Control valve for carbon steel valve body, refers to the maximum allowable working pressure when applied below 200°C; For cast iron valve body, it refers to the maximum working pressure for application below 120°C; Control valve for stainless steel valve body, refers to below 250°C The maximum working pressure allowed during application. When the operating temperature increases, the pressure resistance of the valve body will decrease. For example, a carbon steel control valve with a nominal pressure of 6.4 MPa (PN64) has a pressure resistance of 5.2 MPa at 300°C, a pressure resistance of 4.1 MPa at 400°C, and a pressure resistance of 2.9 MPa at 450°C. .
Third, the pressure valve body material: Cast steel, stainless steel, 316L. Working pressure 0.6-2.5MPA, working temperature -20°C-425°C. Valve diameter DN25-DN300. Connection method: flange. Transmission mode: Manual, pneumatic. Applicable medium: oil, acid, corrosive media and so on. Manufacturing standards: national standard.
The discharge valve is mainly used for bottom discharge, discharge, sampling and no dead-zone shut-down operation of reactors, storage tanks and other vessels. The bottom flange of the valve is welded to the bottom of the tank and other containers, thus eliminating the residual phenomenon of the process medium usually at the outlet of the container. The discharge valve is designed as a flat bottom type and the valve body is V type according to the actual situation. , And provide two ways of lifting and falling valve discs. Valve body cavity has erosion-resistant, corrosion-resistant sealing ring, in the moment of opening the valve, can protect the valve body from media erosion, corrosion, and special treatment of the seal ring, so that the surface hardness of HRC56-62, with high wear resistance, With anti-corrosion function, the valve cover is covered with hard metal as required, and the seal pair is sealed with wire to ensure the reliability of the seal and to prevent scabbing. At the same time take a short stroke valve design.
Fourth, the main equipment performance:
1, discharge valve, corrosion resistance: 1. The use of media such as water, **, alcohol, ammonia, barium carbonate, benzene (WCB material temperature -29 °C -425 °C). 2. The use of media such as particles, oil, pulp, carbon dioxide gas (stainless steel can use the temperature -60 °C -232 °C). 3. Do not use fluoride-containing ionic liquids (such as HF, etc.) nor alkalis and phosphoric acid (temperature less than 150°C, concentration> 30%). 4. The general working temperature of stainless steel is ≤150°C and the pressure range is 0.6-2.5MPA.
2, discharge valve, corrosion resistance: 1. Polytetrafluoroethylene and metal adhesion, tensile strength, resistance to dilute acid, concentrated acid and so on. 2. Use medium such as particles, oil, pulp, carbon dioxide gas (stainless steel can use temperature -60°C-232°C). 3. Do not use fluoride-containing ionic liquids (such as HF, etc.) nor alkalis and phosphoric acid (temperature less than 150°C, concentration> 30%). 4. The general working temperature of stainless steel is -5°C-225°C, and the pressure range is 0.6-1.6MPA. This order must be stated when exceeding this requirement.
3, Discharge valve: The glass-lined device is a vitreous glaze with high silicon content. It is made by applying a high temperature of about 900 degrees to the metal tyre. It has good mechanical properties and corrosion resistance, can prevent the substitution of media and metal ions and affect the pollution products, and the surface is smooth, wearable and has a certain degree of thermal stability. This valve is resistant to various acids, alkalis, salt solutions and organic solvents except phosphorous and phosphorus light media, hydrofluorocarbons, **, sodium hydroxide and potassium hydroxide. A, corrosion resistance: 1. To general inorganic acids, organic acids, weak alkali solution (P ≤ 60 °C PH ≤ 12) and organic media. 2. Better than stainless steel in **, **, etc. strong corrosive media. Do not use fluorine-containing ionic liquids (such as HF, etc.) nor alkalis and phosphoric acid (temperature less than 150°C, concentration> 30%). B, heat resistance, allowed to use between -30 °C -240 °C (fast temperature change less than 120 °C). C, with a smooth surface. Not easy to bond materials, easy to clean. E. Insulation: The impact resistance is less than 2500 g/cm. Therefore, hard impact should be avoided during use. F, pressure 0.6MPA
Fifth, performance and use: construction, installation points
1) The installation position, height, and direction of import and export must meet the design requirements and the connection should be firm and tight.
2) All types of manual valves installed on the insulation pipe shall not be downwards.
3) Before the valve is installed, a visual inspection must be performed. The nameplate of the valve shall comply with the current national standard "General Valve Marking" GB 12220. For valves with a working pressure greater than 1.0 MPa and that act as a shut-off on the trunk pipe, strength and stringent performance tests shall be performed before installation, and they shall be used only after qualification. In the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5 minutes. The valve housing and the packing should have no leakage as qualified. For the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure shall meet the requirements of GB 50243 standard for the duration of the test, and no leakage of the valve sealing surface shall be qualified.
The valve is easy to operate, free to open, flexible and reliable movement; valve disc assembly and maintenance is simple, sealing structure is reasonable, sealing ring replacement is convenient and practical.
Six, structure and principle:
(1) Valve Body, (2) Bracket, (3) Hand Wheel: Cast Iron
(4) spool: stainless steel
(5) rubber gasket
(6) PTFE plate
(7) Packing: PTFE sealing ring
(11) Matching cap: 35#
The discharge valve structure is shown in the figure, and it is suitable for the design of the glass-lined discharge valve with the pressure P ≤ 0.6MPa and the working temperature t ≤ 1500C.
The technical condition of this valve shall comply with the provisions of HG5-16-79. This valve removes phosphorus and phosphorus light medium, hydrofluorocarbon, **, sodium hydroxide, potassium hydroxide
Resistant to various acids, alkalis, salt solutions and organic solvents.