Method of use
- fluorine lined valve flange cover can not be opened at will, unless it is ready to connect with the pipeline, PTFE flange surface may be due to temperature differences, foreign objects caused by bumping scratches or twisted deformation affecting the seal, such as the need to move the cover due to the inspection, but also to be inspected after the speed of the cover will be reset in order to protect the PTFE flange surface.
- Do not allow any high temperature welding work on the fluorine lined butterfly valve, so as not to cause permanent damage to the lining layer.
- after repairing the fluorine lined valves before use should be tested in accordance with relevant standards before installation.
- manual operation of fluorine lined valves, do not allow the use of other levers to force open and close the valve.
- fluorine lined butterfly valve and pipeline connection, generally and no longer use a separate gasket, but with dissimilar materials (metal surface, etc.) flange surface connection, the appropriate gasket should be used to protect the PTFE flange surface.
- fluorine lined valves in the system, such as leakage at higher temperatures, the system temperature should first be reduced to room temperature, and then identify the cause of the repair!
precaution
- fluorine lined valves should not be used in the medium of hard particles, crystals, impurities, etc., so as not to valve in the opening and closing of the operation of the valve spool, seat of the fluorine lining layer or PTFE bellows. The medium has hard particles, crystals, impurities, selection, the valve core, valve seat can be changed to Hastelloy.
- fluorine lined valves used in the media temperature: my company's various types of fluorine lined valves, fluorine plastic is F46 (FEP), the use of media temperature can not exceed 150 ℃ (media temperature for a short period of time can be up to 150 ℃, a long period of time the use of the temperature should be controlled within 120 ℃), otherwise, the valve parts lined with F46 easy to soften, deformation, resulting in the valve can not be shut down, the leakage of large amounts. If the use of the medium temperature for a short period of time in the temperature below 180 ℃, a long period of time in the temperature below 150 ℃, you can choose another kind of fluorine plastic - PFA, but lined with PFA fluorine plastic than lined with F46 in the price to be more expensive.
- pressure, differential pressure should be controlled within the allowable range. Especially the bellows sealed fluorine lined control valve, fluorine lined globe valve. Because the bellows is made of PTFE material, the pressure and differential pressure are large, which can easily lead to the rupture of the bellows. Bellows sealed fluorine lined control valves, the use of conditions of pressure, differential pressure, can be changed to PTFE packing seal.
- fluorine lined valves should be correctly selected according to the required flow (Cv value) the size of the valve diameter. In the selection, should be based on the required flow (Cv value) and other technical parameters to calculate the fluorine lined valve should be selected diameter and valve opening degree, such as the valve diameter selected too large, will inevitably make the valve open for a long time in the case of small operation, coupled with the pressure of the medium, so that the valve is easy to make the valve spool, rod by the impact of the medium and make the valve vibration, the spool rod for a long time in the impact of the medium, and even make the valve rod The spool stem will even break under the long-term impact of the medium. Users in the selection of various types of fluorine lined valves, should be as much as possible to understand, master the use of technical conditions, in order to choose a good, good, improve the service life of the valve. In the event that the use of technical conditions beyond the scope, should be proposed to the manufacturer, the joint consultation, to take appropriate measures to be resolved!
- do not have negative pressure. Fluorine lined valves should be avoided in the pipeline with negative pressure, such as negative pressure, easy to cause the valve cavity of the fluorine lining layer is sucked out (bulging), shelling, resulting in the valve opening, closing failure.