原文：
              腐蚀问题一直是自控仪表中的难题，危害十分严重，有的自动化系统因此不得不改为手动，而且还得频繁地更换被腐蚀的仪表及设备。因此，耐腐蚀问题一直是国内外厂家及设计院关注的问题。

　　一、耐腐蚀材料　

　(1)橡胶有一定的耐腐蚀性，而且价格便宜。 呼吸阀因此在温度不高的情况下被广泛地用在耐腐蚀设备的调节阀上，五、六十年代便产生出了衬橡胶的隔膜阀。为调节大流量的腐蚀介质，进而又产生了衬胶蝶阀。但橡胶并不完全耐腐蚀，且使用温度，耐压条件受到一定的限制。

　　(2)聚四氟乙烯(外文简称为F4、PTFE)，是当今最好的耐腐蚀材料，被称为“耐腐蚀王”。它具有非常优良的耐蚀和耐热性能，可在-250～250℃温度内长期使用。除在高温高压下氟元素和熔融状态的碱金属对它有腐蚀作用，某些卤化物或芳香烃使其有轻微的膨胀外，其它诸如强酸(包括浓硝酸和王水)、强碱、强氧化剂、油脂、酮、醚、醇等即使在高温下也对它不起作用。它几乎可以抵抗所有化学介质而不受其腐蚀。

　　(3)聚四氟乙丙烯是一种耐腐蚀、耐温性能极好的新型材料，具有高度的化学稳定性和优良的耐化学腐蚀力,如耐强酸、强碱、强氧化剂等。调节阀它还有突出的耐热、耐寒性，可长期使用在温度-00～250℃环境下；同时，还有不粘连、不吸水、不燃烧等特点。此外，该材料具有较好的流动性，可内衬于部件表面作为耐腐蚀材料使用。

　　(4)早在二三十年代，国外便有耐蚀合金如哈氏合金、蒙乃尔合金，而国内五六十年代才起步。把耐腐蚀合金用在调节阀领域是从八十年代开始的，但因耐腐蚀合金价格太贵而无法被广泛推广使用。

 　　二、耐腐蚀阀系列

　　(1)全四氟耐蚀单座调节阀 　　全四氟耐腐蚀单座调节阀采用金属外壳与聚四氟乙烯镶嵌的结构形式。金属外壳一般用碳钢或不锈钢，阀体内部与介质接触的部分(容腔、通道、节流件等)全部采用聚四氟乙烯，将阀体材料与腐蚀性介质隔离开来，从而使腐蚀性问题得到了较彻底的解决，尤其是在硫酸、盐酸、湿氯气等介质中使用效果尤为突出。该产品于92年获得了国家专利(专利号：ZL 92 2 20634.1)。

　　(2)衬氟O型球阀　　衬氟球阀又称水处理专用球阀，主要用于强碱、减压阀水处理(脱盐水)的两位控制装置中。它采用内衬氟塑料方式，将耐腐蚀材料内衬于阀体内，保证与各种强腐蚀介质接触的部分均为氟塑料，将腐蚀介质与阀体材料隔离开；在结构上，由于球阀的球芯是一个刚度好、可靠性好的零件，从根本上解决了过去隔膜阀的隔膜片不可靠的缺陷，提高了阀的可靠性并延长了使用寿命。因此，衬氟球阀是替代隔膜阀的最佳产品。该产品于92年获得了国家专利(专利号：ZL 92 2 20636.8)。

　　(3)衬氟V形球阀　　衬氟O型球阀只适用于两位调节切断，在含有杂质的强腐蚀介质的调节场合适用衬氟V型球阀，它的结构、安装尺寸和衬氟O型球阀一样，只是球芯开的是具有调节特性的V型孔，这样，它不仅防堵性能好，而且在小开度工作时调节性能也好。在含有颗粒、粘稠、悬浮液等介质中，建议选用该耐腐蚀阀。

 　　(4)衬氟蝶阀　　衬氟蝶阀适用于大口径、大流量的强腐蚀调节场合。锻钢阀门它采用同衬氟球阀一样的工艺，将氟塑料内衬于阀体内，保证与强腐蚀性介质接触的材料均为耐腐蚀性能优异的氟塑料。因此，它也具有优异的耐腐蚀性。同时采用蝶阀结构也具有极好的防堵性能。该产品于92年获得了国家专利(专利号：ZL 92 2 20635 X)。

　　(5)耐蚀合金阀 　　耐蚀合金阀适用于压力过大(大于2.5 Mpa)温度过高过低(高于180℃，低于-40℃)的应用场合，但因采用价格极高的材料使得该阀价格极高。建议DN≤20，选用直通单座阀结构；25≤DN≤150，选用全功能阀结构；DN≥200，针型阀选用蝶阀结构，这样可大幅度降低成本，提高使用性能价格比。

 　　三、不推荐使用的产品

　　(1)衬氟塑料隔膜阀 在上世纪80年代前，由于一时找不到更好的耐蚀阀，所以在很长一段时间内，衬氟塑料的隔膜阀被许多厂家广泛使用。但据现场使用反馈表明，该阀具有两个明显的缺陷。一是可靠性差、寿命短。氟塑料制成薄的膜片，在工作时被强迫作上下折叠极易折破；二是笨重，在调节阀逐渐向小型化、轻型化、仪表化方向发展的同时，隔膜阀始终无法减轻重量。因为隔膜受到阀前后介质压力的作用，其不平衡推力十分大，相应的执行机构推力也必须十分大，无法减轻其重量。

　　(2)合金双座阀、套筒阀合金价格贵，数百元至上千元一公斤，这种结构太耗材料，不宜选用，应选节约材质的全功能超轻型阀或蝶阀。

“ Corrosion Control Valve Selection Tips ”是由中国调节阀网提供的国际阀门新闻，译文仅供参考。另外，中国调节阀网还提供相关产品搜索： CV3000调节阀、 电动调节阀、 执行器和附件、 更多调节阀产品、 调节阀价格等。

译文：
          Corrosion has been the instrument of self-control problem, very serious harm, and some automated systems had to be changed manually, and have to frequently replace the corroded devices and equipment. Therefore, corrosion has been the domestic and foreign manufacturers and Design Institute of concern. 1, corrosion-resistant materials (1) rubber have a certain resistance to corrosion, and inexpensive. Therefore, in the case of high temperature are widely used in corrosion resistant equipment, control valve, the fifties and sixties will produce a rubber diaphragm lining. To regulate large flow Filters of corrosive medium, which in turn produced a rubber lined butterfly valves. But the rubber does not completely resistant, and the temperature, pressure conditions are subject to certain restrictions. (2) Teflon (foreign language referred to as F4, PTFE), is today the best corrosion resistant material, known as the "king of corrosion." It has very good corrosion and heat resistance, can be the temperature at -250 ~ 250 ℃ within the long-term use. In addition to high temperature and pressure fluorine and molten alkali metal to its corrosive effects, some of aromatic halide or to a slight expansion, the other, such as strong acids (including concentrated nitric acid and aqua regia), strong base, strong oxidant, fat, ketones, ethers, alcohol, etc. Even if it does not work at high temperatures also. It can resist almost all the media from its chemical corrosion. (3) PTFE FEP is a corrosion-resistant, excellent heat resistance of new materials with high chemical stability and excellent resistance to chemical corrosion strength, such as resistance to acids, alkalis, strong oxidizers, etc.. It also has outstanding resistance to heat, cold, long-term use at temperatures under -00 ~ 250 ℃; the same time, there is no adhesion, non-absorbent, non-burning and so on. In addition, the material has good mobility, can be lined on the part surface as a corrosion-resistant material used. (4) back in the twenties and thirties, and foreign have corrosion resistant alloy such as Hastelloy, Monel alloy, while the domestic fifties and sixties it started. The corrosion-resistant alloy used in valve area is from the beginning of eighties, but too expensive corrosion-resistant alloys can be widely used. Second, corrosion-resistant valve series (1) All single-seat control valve PTFE corrosion Corrosion-resistant single-seat all PTFE valve and PTFE metal shell mosaic structure. Metal generally carbon steel or stainless steel, the internal body parts in contact with the medium (chamber volume, channel, cutting parts, etc.) all with PTFE, the body material and the corrosive medium to isolate, so that corrosion of the problem is a more thorough solution, especially in the sulfuric acid, hydrochloric acid, chlorine and other media used wet effect is particularly prominent. The product was Forged Steel Valves obtained 92 national patents (Patent No.: ZL 92 2 20634.1). (2) fluorine O type ball valve Special ball valve ball valve, also known as fluorine treatment, mainly for alkali, water treatment (desalination of water) of the two control devices. It uses way within the fluorine plastic, corrosion-resistant materials will be lined on the valve body, ensuring access to various parts of strong corrosive medium are fluorine plastic, corrosion media and body material will be separated; in structure, due to valve stiffness of the ball core is a good, reliable good parts, a fundamental solution to diaphragm Diaphragm past is not reliable, and improves the reliability and extended valve life. Therefore, the fluorine substitution diaphragm valve isReducing Valves the best product. The product was obtained 92 national patents (Patent No.: ZL 92 2 20636.8). (3) fluorine V-ball Fluorine O type ball valve adjustment applies only to the two cut off, in the presence of impurities in the regulation of strong corrosive medium for fluorine V-ball situations, its structure, installation dimension and fluorine O type ball valve only, the ball core open is a regulation characteristics of the V-hole, so that not only attempts to prevent the performance, but a small opening in the work of adjusting performance 也好. Containing particles, viscous, suspension and other media, suggested the use of the corrosion-resistant valve. (4) fluorine valve Fluorine valve for large diameter, large flow of strong corrosion regulation occasions. It uses the same technique with fluorine valve, fluorine plastic lining in the valve body, to ensure strong corrosive medium in contact with the material are excellent corrosion resistance of fluorine plastics. Therefore, it also has excellent corrosion resistance. At the same time using butterfly structure has excellent Anti blocking performance. The product was obtained 92 national patents (Patent No.: ZL 92 2 20635 X). (5) corrosion resistant alloy valve Corrosion resistant alloys for pressureAPI Cast Steel Valves valve is too large (greater than 2.5 Mpa) low temperature is too high (above 180 ℃, lower than -40 ℃) for applications, but high prices of materials used makes the valve very high price . Proposed DN ≤ 20, use the structure through single-seat valve; 25 ≤ DN ≤ 150, use full-function valve structure; DN ≥ 200, use butterfly structure, this can greatly reduce costs, improve use of cost performance. Third, the product is not recommended (1) fluorine plastic diaphragm 80 in the last century before, could not find a better corrosion resistance as valve, soWater power control valves in a very long time, fluorine plastic diaphragm widely used by many manufacturers. However, according to the scene use the feedback showed that the valve has two obvious flaws. First, poor reliability, short life. Fluoride thin plastic membrane, at work were forced to break off easily folded up and down; second is heavy, the valve gradually to smaller, lighter and instrumentation in the direction of development, the diaphragm has failed to reduce weight . Because the diaphragm by the valve before and after the media pressure, the unbalanced thrust is very large, the corresponding actuator thrust must be very large to reduce its weight. (2) alloy seat valve, sleeve valve alloy expensive, several hundred thousand dollars first one kilogram, this structure is too consumed material, should not be used, saving material should be selected full-featured ultra-light valve or butterfly valve.

原文来源：http://www.1tiaojiefa.com/

2010-08-23 08:46

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