Matters needing attention when purchasing fluorine-lined valves
Fluorine-lined valves are widely used in industries with strong corrosive media (such as petroleum, chemical, pharmaceutical, metallurgy and electric power and other acids and alkalis). When choosing fluorine-lined valves, pay attention to the following items, temperature, pressure, pressure difference and other conditions.
1. The medium conditions used in the valve: The medium conditions used in the valve include hard particles, which can prevent the valve core, the fluorine plastic layer of the valve seat or the PTFE bellows Wear when the valve opens and closes. For media containing hard particles, crystals and impurities, the valve core and valve seat can be changed to Hastelloy.
2. No negative pressure: The valve should avoid negative pressure in the pipeline. When there is negative pressure, the fluoroplastic layer in the internal cavity of the valve will be sucked out (protruding) and removed from the shell, causing the valve to open and close.
3. The pressure and pressure difference should be controlled within a certain range. In particular, regulating valves and globe valves are lined with fluoroplastic and sealed with bellows. Since the bellows is a PTFE material, the pressure and pressure difference are large, and the bellows is prone to rupture. If the pressure and pressure difference are large under working conditions, the fluoroplastic lined control valve sealed by the bellows can be replaced with a PTFE packing seal.
4. The medium temperature used by the fluorine-lined valve: Our various fluoroplastic valves use F46(FEP), and the medium temperature used cannot exceed 150°C (the medium temperature is short). It can reach 150°C in time), and the long-term working temperature must be controlled within 120°C. Otherwise, the F46 lining of the valve assembly will become soft and easily deformed, which will cause the valve to close fatally and cause a large amount of leakage. If the temperature of the medium used is less than 180°C in the short term and less than 150°C in the long term, another fluoroplastic-PFA-can be used, but the PFA fluoroplastic lining is more expensive than the F46 lining.
When choosing different types of fluorine-lined valves, users need to understand and master the technical requirements as much as possible so that they can select and use them to extend the service life of the valve. If the technical conditions of use are exceeded, recommendations must be made to the manufacturer, discussed, and appropriate measures must be taken to solve them.
The fluorine-lined valve not only bears the internal pressure of the fluid, but also bears the stress of the pipeline, the gravity of the sphere and other additional forces. The design must consider tightness and strength. corrosion, manufacturing process and other factors.
Fluorine-lined valves are made of ptfe-lined butterfly plates with spherical sealing surface layers, and silicone gaskets at the base of high-pressure gate valves are used to adjust the sealing performance of valves. The pneumatic valve has light weight, tight sealing performance and long service life. It can be used for quick disconnection or flow adjustment. Applicable to the provisions of reliable sealing and excellent adjustment characteristics of the place.
Fluorine-lined valve has the dual function of switching and flow regulation, which can easily open and close the gas path without affecting the flow and ensuring the repeatability of the flow. The slow start reduces the impact of the instantaneous pipeline pressure on the instrument.
On March 18, the equipment and thermal engineering joint party branch of Chongqing water pump factory co., ltd organized the 2018 annual organization life meeting. At the meeting, all the party members of the branch carefully looked for their own shortcomings, spoke actively, adopted mutual evaluation of party members, directly pointed out problems and showed signs, and did not engage in harmony with each other. The named party members all expressed their attitude and accepted criticism from others modestly.