Cryogenic valves application knowledge is introduced

A, cryogenic application option 1, the operator use the valve in the cold environment, such as the polar sea oil RIGS. 2, the operator to use the valve to manage temperatures well below freezing. Second, what affect the valve design? Temperature has important effect on the design of the valve. For example, the user may need it hot environment for the Middle East, etc. Or, it may be suitable for cold like polar ocean environment. These two kinds of environment will affect the impermeability and durability of the valve. These valve components including body, valve cover, valve stem, valve stem seal, ball valve and valve seat. Because of the different material components, these components expansion and shrinkage under different temperatures. Three, engineers how to ensure that cryogenic valves sealing? When people consider first made the cost of the refrigerant, the gas leak is very expensive. It is also very dangerous. A big problem of low-temperature technology is the possibility of a valve seat leakage. Buyers often underestimate the stem and body related to the radial and linear growth. If the buyer to select the correct valve, they can avoid the above problems. It is recommended to use made of stainless steel materials of cryogenic valves. In the use of liquefied gas during operation, the material is very good way of dealing with temperature gradient. Cryogenic valves should use proper sealing material, sealing up to 100 bar. In addition, the extended bonnet is a very important feature, because it determines the stem sealing sealant. Four, chose for low temperature service valves for cryogenic application valve can be very complex. The buyer must take account of the ship and the conditions of the factory. Moreover, the specific nature of low temperature fluid requires a specific performance of the valve. Correct selection can ensure the dependability of the factory, equipment protection and safe operation. The global LNG market by two main valve design. 1, single panel and double panel check valves is the key components in liquefaction equipment, because they can prevent damage caused by the flow reversal. Material and size is an important consideration, because cryogenic valves are expensive. The result of incorrect valve could be harmful. 2, three bias closely isolation valve rotating these migration allows the valve open and close. They are small friction and friction in operation. It also USES more sealing valve stem torque. One of the challenges of the LNG storage is trapped in the cavity. In the cavity, liquid explosive to expand more than 600 times. Three rotating closely isolation valves eliminates this challenge. Five, in the case of a highly flammable gas, such as natural gas or oxygen, in the case of fire, the valve must also be properly. 1, the temperature problem severe temperature changes will affect the safety of workers and the factory. Due to the different material composition and length of time they undergo refrigerant, cryogenic valve of each parts expand and contract at different rates. When handling refrigerant of another big problem is the heat from the surrounding environment. Increase the quantity of heat is manufacturer isolation valves and piping. In addition to the high temperature range, the valve must also cope with considerable challenge. For liquid helium, liquefied gas temperature drop to - 270° C。 2, function problem, on the other hand, if the temperature dropped to absolute zero, the valve function becomes very challenging. Cryogenic valve connecting pipes and the liquid gas to the environment. It's in ambient temperature to do this. Results may be between pipeline and environment temperature as high as 300 & deg; C。 3, the efficiency problem of temperature difference to produce heat from the warmer area to cold area. It will damage the normal function of the valve. It will also reduce the system efficiency in extreme circumstances. If the ice formed in the warm side, this is of particular concern. But in low temperature applications, this is deliberately using passive heating process. The process is used for sealing the valve stem. Usually, the valve stem with plastic seal. These materials can't endure low temperature, but the two parts of high performance metal seal, they move in the opposite direction, just is very expensive and almost impossible. 4, pressure problems exist in the normal processing of refrigerant pressure accumulation. This is the increased heat to the environment and the subsequent formation of steam. When designing valve/pipe system need special attention. This allows the pressure buildup. 5, the problem of sealing problems, there is a very simple solution. You will be used to seal the valve stem plastic area relatively normal temperature. This means that the valve stem of the sealant must keep a certain distance with fluid. Hood is like a pipe. If the fluid to rise from the pipeline, it will be from the outside temperature warming. When the fluid to stem sealants, it mainly at ambient temperature and the gaseous. Hood can also prevent the handle frozen and cannot be started.