Large-diameter globe valves are generally used in boiler outlets, main gas-distributing cylinders, main steam pipes and so forth. Generally, the pressure difference at the boiler outlet is large, so the steam velocity is high and the erosion destruction to the sealing surface is great. In addition, the combustion efficiency of the boiler cannot be 100%, otherwise the steam at the outlet of the boiler will have a large water content, easily causing cavitation to the valve...
Causes of Internal Leakage of Large-diameter Globe Valves Read
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1. For the main pipeline used for oil and natural gas transmission, as well as the pipe that needs to be cleaned and buried underground, the ball valve with full bore and fully welded structure should be selected. 2. For the pipe buried above ground, choose full bore ball valve with welded connections or flange connections. For branch pipes, pick ball valves with flange connections or welded connections, full bore ball valves or reduced bore ball valves....
The Selection of Ball Valves Read
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Like other fields, the valve industry also faces some difficulties. Only by solving these problems as soon as possible can the valve be better applied to the pharmaceutical industry. First, R&D investment is insufficient for a long time. Insufficient investment in scientific research has become an important factor restricting independent research and development of valve enterprises. Second, the capacity for independent innovation is weak. Although China's pump manufacturing industries have...
Valves Used in the Pharmaceutical Industry (Part Two) Read
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1. Check whether the ball valve is in the fully open position. After injection of grease, first check whether the diameter of the ball is flush with the inner cavity plane of the valve seat. If there is any difference, adjust the stop bolt on the actuator to ensure that the valve is fully open. Otherwise, once the valve is installed, it is impossible to judge whether the valve is in the fully open position. 2. Lubricating grease can't be injected into the valve. (1)...
Maintenance of the Ball Valve before Operation Read
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In most cases, austenitic stainless steel is a widely used valve material, and the valve made from this material can be applied to the pharmaceutical industry. In the clean piping system of the pharmaceutical industry, there are special requirements for valves to avoid stagnant water as much as possible. "Among the many valves, the diaphragm valve is commonly used. Due to its special design, the medium in the pipeline will not contact pipe fittings except the gasket,...
Valves Used in the Pharmaceutical Industry (Part One) Read
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1. Which three main factors should be considered in selecting valve actuators? (1) The output of the actuator should be greater than the load of the valve. (2) During the check of standard combination, consider whether the allowable pressure difference of the valve meets the technological requirements. When the pressure difference is large, the unbalanced force on the valve core should be calculated. (3) It is necessary to consider whether the response speed of the actuator meets...
Knowledge of Valves Read
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1. Price Whether they are domestic pneumatic valves and electric valves or imported pneumatic and electric ones, their prices are essentially the same. However, because pneumatic valves need to be equipped with air source facilities (e.g. the air compressor station), the electric valve has an advantage in price. 2. Reliability of valves It is believed that pneumatic valves have extremely high reliability while the reliability of...
The Pros and Cons of Pneumatic Valves and Electric Valves Read
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The ductile iron is ideal for valve materials, for it has lots of merits. As a substitute for steel, ductile iron was developed in 1949. The carbon content of cast steel is less than 0.3%, while that of cast iron and ductile iron is at least 3%. The low carbon content of cast steel makes the carbon existing as free graphite not form flakes. The natural form of carbon in cast iron is free graphite flakes. In ductile iron, graphite is in the form of nodules rather than flakes as in cast iron....
Advantages of Using Ductile Iron as Valve Materials Read
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1. For natural gas ball valve, conductive springs are set between the ball and the stem, and between the stem and the valve body to form electrostatic channels, thus achieving the purpose of removing static electricity and avoiding igniting flammable medium by electrostatic ignition to ensure system security. In case of fire, the soft seal ring such as PTFE O-rings being burned, the ball valve can still operate reliably and has good sealing to prevent the spread of...
The Feature of Natural Gas Ball Valves Read
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When defects appear on the sealing surfaces of valve heads and valve seats, if the defect depth is less than 0.5mm for valves without being nitrided, abrasive machining shall be done directly to eliminate the defects or the method of lathe machining before abrasive machining shall be adopted, which depends on the damage condition of the sealing surfaces. If the surface of the valve is nitrided, the valve should be nitrided again after eliminating the defects on the sealing...
The Method for Eliminating Defects on Valve Sealing Surfaces Read
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