Installation precautions and operation performance of anticorrosive fluorine plastic valve What should be paid attention to in the installation of liquefied gas valve

Installation precautions and operation performance of anticorrosive fluorine plastic valve What should be paid attention to in the installation of liquefied gas valve

Anticorrosive fluorine lined plastic pump is a commonly used anticorrosive pump for conveying corrosive liquids such as acid, alkali and salt. At the same time, when using fluorine lined pump, connecting valve pipeline must also be anticorrosive. What needs to be paid attention to in the service performance and installation of fluorine lined plastic valve? Reasonable selection and application of the lining fluorine plastic anti-corrosion valve, everybody CARES in engineering problem, fluorine plastic anticorrosive pump and valve in the petroleum, chemical industry, medicine, metallurgy, electric power industries strong corrosive medium such as acid-base contact device has been applied, but for how to choose good, with good lining fluorine plastic valves, according to our customers for many years field application experience, The following precautions should be put forward for the use of the medium temperature, pressure, pressure difference and other conditions when the fluorine lined anti-corrosion valve is selected:
1, lined with fluorine plastic valve using medium conditions
The medium condition of fluorine lined plastic valve should not have hard particles, crystals, impurities, etc., so as not to wear out the fluorine lined plastic layer or PTFE bellows of valve core and valve seat in the operation of opening and closing. The medium has hard particles, crystals, impurities, selection, spool, seat can be used to Hastelloy.
2, lined with fluorine plastic valve medium temperature.
Lined with fluorine plastic valve, the fluorine plastic is F46 (FEP), the use of medium temperature can not exceed 150℃ (medium temperature can be 150℃ for a short time, long time use temperature should be controlled within 120℃), otherwise, the valve of each component lining F46 easy to soften, deformation, resulting in the valve closed, large leakage. If the medium temperature is used for a short time, the temperature is below 180 ° C, and the temperature is below 150 ° C for a long time, another kind of fluoroplastic-PFA can be selected, but the PFA fluoroplastic lining is more expensive than the F46 lining in the price, and the choice of the lining pump material is the same.
3, do not have negative pressure.
Fluorine lined plastic valve should avoid the use of negative pressure in the pipeline, if there is negative pressure, easy to cause the fluorine lined plastic layer in the valve cavity is sucked out (drum out), peeling, leading to valve opening and closing failure.
4, lined with fluorine plastic regulating valve should be according to the required flow (Cv value) correct selection of valve diameter size.
When choose, should according to the need of traffic (Cv) and other technical parameters are calculated the valve size should be chosen and the opening of the valve, such as valve’s size too big, certainly will makes the valve in the opening for a long time running, under the condition of rather smaller and medium pressure, so easy to make the valve core and valve rod by the impact of the media and make the valve vibrates, The valve core rod in the medium for a long time under the impact, even will make the valve stem fracture.
5, pressure, pressure difference should be controlled within the permissible range.
Especially bellows seal lined fluorine plastic regulating valve, globe valve. Because the bellows are made of tetrafluoric materials, the pressure and pressure difference are large, which can easily lead to the rupture of the bellows. Bellows seal lined fluorine plastic regulating valve, the use of condition pressure, pressure difference is large, can be changed to PTFE packing seal.
LPG valve installation notice what the LPG valve is a forced sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from below the disc, the resistance to be overcome by the operation force is the friction force of the stem and packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than the force of opening the valve, so the diameter of the valve stem is large, otherwise the fault of the stem top bend will occur. What should we pay attention to when installing the liquefied gas valve? The online Xiaobian of the valve will answer it for you.
The LPG valve is a forced sealing valve, so when the valve is closed, pressure must be applied to the disc to force the sealing surface not to leak. When the medium enters the valve from below the disc, the resistance to be overcome by the operation force is the friction force of the stem and packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than the force of opening the valve, so the diameter of the valve stem is large, otherwise the fault of the stem top bend will occur. What should we pay attention to when installing the liquefied gas valve? The online Xiaobian of the valve will answer it for you.
Notes for installation and maintenance of liquefied gas valve:
The grain pipe stop valve operated by hand wheel and handle can be installed at any position in the pipe.
Handwheel, handle and lifting mechanism are not allowed to be used for lifting.
The flow of the medium shall be consistent with the direction of the arrow shown on the valve body.
Liquefied gas valve, also known as the door stop, is a kind of valve used. It is popular because the friction between the sealing surface in the process of opening and closing is small, relatively durable, the opening height is not large, easy to manufacture, convenient maintenance, not only suitable for medium and low pressure, but also suitable for high pressure. Its closure principle is to rely on the valve bar pressure, so that the valve disc sealing surface and seat sealing surface close fit, prevent media flow.
The LPG valve only allows unidirectional flow of medium and has directionality when installed. Its structure length is longer than the gate valve, at the same time, the fluid resistance is large, long-term operation, sealing reliability is not strong.
LPG valves are divided into three categories: straight through, right Angle and straight flow oblique globe valves.
When the LPG valve IS opened, THE opening height of the valve disc is 25% ~ 30% of the nominal diameter, and the flow rate has reached a relatively large, indicating that the valve has reached a fully open position. So the full open position of the globe valve should be determined by the stroke of the valve disc.