If it is leaking, what is the cause? #1 At the point of contact between the two sealing surfaces of the poppet and the valve seat; #2 Where the packing mates with the stem and stuffing box; #3 The connection between the valve body and the valve cover. One of the first leakage is called internal leakage, which is often referred to as the closure is not tight, it will affect the valve’s ability to cut off the medium. The last two leaks are called external leakage, that is, the medium from the valve leakage to the outside of the valve. Leakage will cause material loss, pollution of the environment, and in serious cases will cause accidents. Falling into place, the analysis of internal leakage, internal leakage in general: The valve according to its different calibers, different differential pressure of the system, and the system medium, is not the same, and there is a permissible internal leakage standard. In a strict sense, the real ‘0’ leakage of the valve does not exist. In general, small-diameter globe valves are easy to achieve invisible leakage (not zero leakage), while large-diameter gate valves to achieve invisible leakage is very difficult. When encountering the...
The valve according to its different calibers, different differential pressure of the system, and the system medium, is not the same, and there is a permissible internal leakage standard. In a strict sense, the real ‘0’ leakage of the valve does not exist. I. Preventive measures on valve leakage of water and steam. #1 All valves must be subjected to different levels of hydrostatic test after entering the factory. #2 It is necessary to disassemble the overhaul of the valve must be ground. #3 In the process of overhauling must carefully check whether there is added packing, the packing gland is tightened. #4 Valves must be checked for dust, sand, iron oxide, and other debris inside the valve before installation. If there is any of the above debris must be cleaned up before installation. #5 All valves must be fitted with gaskets of appropriate grade before installation. #6 Fasteners must be tightened when installing the flange door, and the flange bolts must be tightened in symmetrical direction for sequential tightening. #7 In the process of valve installation, all valves must be installed correctly according to the system and pressure, and it is strictly prohibited to install indiscriminately or mixed. For...
What is a rubber joint? Rubber joints can also be called: flexible rubber joints, rubber soft connections, soft joints, flexible rubber joints, and rubber expansion joints. They are pipe connections with high elasticity, high air tightness, medium resistance, and weather resistance. There are three types: loose sleeve flange type, fixed flange type, and threaded type; the structure includes single sphere, double sphere, different diameter body, etc. The rubber joint is generally composed of the inner rubber layer, fabric reinforcement layer (the reinforcement layer has multi-layer scraped nylon cord fabric), middle rubber layer, outer rubber layer, end reinforced metal ring or steel traveler, after high temperature and high-pressure vulcanization molding, and Composite rubber pipe composed of metal flange or loose sleeve of the parallel joint. This product utilizes the advantages of the high elasticity, high gas, medium resistance, weather resistance, and radiation resistance of rubber, which can reduce the vibration and noise of the pipeline, and can compensate for thermal expansion and contraction. According to different media, the rubber materials used are also different, such as natural rubber, styrene-butadiene rubber, butyl rubber, nitrile rubber, EPDM rubber, neoprene rubber, silicone rubber, fluorine rubber, and so on. Respectively have heat resistance, acid resistance,...
How to select the Solenoid valve and what should be paid attention to in the installation working principle: 1. Direct-acting solenoid valve Principle: When the normally closed direct-acting solenoid valve is energized, the electromagnetic coil generates electromagnetic suction to lift the valve core, so that the seal on the valve core leaves the valve seat, and the valve opens; The seal on the core presses against the seat opening and the valve closes. (Normal open type is opposite to this) Features: It can work normally under vacuum, negative pressure, and zero pressure difference. The larger the valve diameter, the larger the volume and power of the solenoid head. 2. Step-by-step direct-acting solenoid valve (recoil type) Principle: Its principle is a combination of direct action and pilot. When the power is turned on, the solenoid valve first opens the auxiliary valve, and the pressure in the lower cavity of the main valve is greater than the pressure in the upper cavity, and the valve is opened by using the simultaneous action of pressure difference and electromagnetic force; When electrified, the auxiliary valve uses spring force or medium pressure to push the closing seal and move down to close the valve port. Features:...
Introduction: A globe valve is a type of valve used in the pipeline to regulate and control the flow of the liquid or gas from one side to another side. It consists of a rotating disk that controls an opening in a pipeline by sealing it shut when the disk is turned so that only one way opens at any given time; thus allowing control over the flow rate while preventing leakage past any point where there may be damage to piping materials such as their threads or seals. The main advantage of globe valves is that they can be used for both on-off applications and for throttling applications. Application of globe valves: The globe valve is used in many industries, they can be used for water, gas, steam, and oil, including the process of chemical, pharmaceutical, and food processing. Because of its reliability and flexibility to completely shut off the flow, globe valves are therefore popularly used in industrial plants where there is an application for these pressures and temperatures. These include chemical plants, water treatment plants, oil refineries, pulp, and paper plants. 1. The first major application for globe valves is in water supply and wastewater systems. They...
Introduction If you’re getting a new pipe installed, you might have noticed there are different types of valves available. Some of them are much easier to install than others. In this article, we’ll walk you through the process of installing a lug butterfly valve—a type that’s designed to be easy and quick. 1. Disconnect the power. In order for you to safely install a lug butterfly valve, you will need to disconnect the power. This is because the lug butterfly valve is water and electrical hazard. To be safe, you should completely shut down any power to the valve and make sure all water connections are unplugged from their respective valves. 2. Unscrew the lug valve from the pipe. You can use various types of wrenches to unscrew the lug valve from the pipe. The most common options are: ①A wrench with a single handle that turns in either direction ②A wrench with two handles, one on each end (this is sometimes called a “combination” or “offset” wrench) ③A crescent wrench, which has the same shape as a pipe wrench except it’s small and can fit into tight spaces You may also be able to use ratcheting wrenches, which have...
Why does 304 stainless steel pipe leak? Chloride ion poisoning: The corrosion resistance of stainless steel is due to the formation of an extremely thin, well-adhesive, translucent chromium oxide film on the surface of the stainless steel. Once this film layer is damaged, the chemical reaction between the chromium in the steel and the oxygen in the atmosphere can quickly restore this film layer. At the same time, mechanical damage can quickly regenerate a protective film. However, if ions, especially chloride ions chemically attack it, it will quickly dissolve and corrode. As a result, needle-like or point-like holes with a certain depth appear on the metal surface. The mechanism of this kind of pitting corrosion is that ions in a neutral solution, such as chloride ions, act on the surface passivation film, and the surface film is damaged, so pitting corrosion occurs, and the uneven parts of the metal structure, such as tissue and inclusions are easy to become spots. Source of erosion: Of course, many other forms of corrosion on austenitic stainless steel, such as crevice corrosion, stress corrosion, etc. Austenitic stainless steels are extremely sensitive to chloride ions, which can occur quickly if the temperature and concentration are...
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