译文：
石油、化工工业在国民经济中占据非常重要的位置，化工流程泵作为关键配套设备也越来越受到人们的关注。由于化工介质的特性错综复杂，加之对环境保护和设备能耗的要求不断提高，作为化工生产厂家，我们应如何对化工泵进行选型？应重点注意哪些方面？…等等显得尤为重要。现结合多数化工公司相关产品特点以对常用化工泵的选型做一点简要评述，希望能有益于广大客户在该领域更好地开展工作。 一、氟塑料泵的选型应考虑以下问题： 1、耐腐蚀问题：长期以来，腐蚀就是化工设备最xx的危害之一，稍有不慎，轻则损坏设备，重则造成事故甚至引发事故。据有关统计，化工设备的破坏约有60%是由于腐蚀引起的，因此在化工泵选型时首先要注意选材的科学性。通常有一种误区，认为不锈钢是“{wn}材料”，不论什么介质和环境条件都捧出不锈钢，这是很危险的。下面针对一些常用化工介质谈谈选材的要点： 1）硫酸：作为强腐蚀介质之一，硫酸是用途非常广泛的重要工业原料。不同浓度和温度的硫酸对材料的腐蚀差别较大，对于浓度在80%以上、温度小于80℃的浓硫酸，碳钢和铸铁有较好的耐蚀性，但它不适合高速流动的硫酸，不适用作泵阀的材料；普通不锈钢如304（0Cr18Ni9）、316（0Cr18Ni12Mo2Ti）对硫酸介质也用途有限。因此输送硫酸的泵阀通常采用高硅铸铁（铸造及加工难度大）、高合金不锈钢（20号合金）制造，但其加工难度大和价格昂贵，因此不被人们看好。氟塑料合金具有很好好的耐硫酸性能，它是中国科学院上海有机化学研究所的专利材料，我公司于1985年引进的专利技术，最早用其开发并生产耐腐蚀化工泵，经中科院实验证明，目前尚未发现在适用温度范围内有哪种化学介质与其能产生反应，因此采用衬氟泵（F46）是一种更为经济的选择。公司适用产品有：CQB氟塑料磁力泵、IMD衬氟磁力泵、IHF衬氟离心泵、FSB氟合金离心泵等。 2）盐酸：决大多数金属材料都不耐盐酸腐蚀（包括各种不锈钢材料），含钼高硅铁也仅可用于50℃、30%以下盐酸。和金属材料相反，绝大多数非金属材料对盐酸都有良好的耐腐蚀性，所以内衬橡胶泵和塑料泵（如工程塑料、氟塑料等）是输送盐酸的{zh0}选择。公司适用产品有：CQB氟塑料磁力泵、IMD衬氟磁力泵、IHF衬氟离心泵、FSB氟合金离心泵、UHB聚乙稀离心泵等。 3）硝酸：一般金属大多在硝酸中被迅速腐蚀破坏，不锈钢是应用最广的耐硝酸材料，对常温下一切浓度的硝酸都有良好的耐蚀性，值得一提的是含钼的不锈钢（如316、316L）对硝酸的耐蚀性不仅不优于普通不锈钢（如304、321），有时甚至不如。而对于高温硝酸，通常采用氟塑料合金材料。公司适用产品有：CQB氟塑料磁力泵、IMD衬氟磁力泵、IHF衬氟离心泵、FSB氟合金离心泵等。 4）醋酸：它是有机酸中腐蚀性最强的物质之一，普通钢铁在一切浓度和温度的醋酸中都会严重腐蚀，不锈钢是优良的耐醋酸材料，含钼的316不锈钢还能适用于高温和稀醋酸蒸汽。对于高温高浓醋酸或含有其它腐蚀介质等苛刻要求时，可选用高合金不锈钢或氟塑料泵。如CQB氟塑料磁力泵、IMD衬氟磁力泵、IHF衬氟离心泵、FSB氟合金离心泵等。 5）碱（氢氧化钠）：一般腐蚀性不是很强，但一般碱溶液都会产生结晶，因此可选用配置硅化石墨169材质机械密封的IHF衬氟离心泵和FSB氟合金离心泵。 6）氨（氢氧化氨）：大多数金属和非金属在液氨及氨水（氢氧化氨）中的腐蚀都很轻微，只有铜和铜合金不宜使用。公司产品大多适用于氨及氨水的输送。如氟塑料磁力泵、氟塑料离心泵均可长期稳定的使用。 7）盐水（海水）：普通钢铁在氯化钠溶液和海水、咸水中腐蚀率不太高，一般须采用涂料保护；各类不锈钢也有很低的均匀腐蚀率，但可能因氯离子而引起局部性腐蚀，通常采用316不锈钢较好。公司各类化工泵均可适用。 8）醇类、酮类、酯类、醚类：常见的醇类介质有甲醇、乙醇、乙二醇、丙醇等，酮类介质有丙酮、丁酮等，酯类介质有各种甲酯、乙酯等，醚类介质有甲醚、乙醚、丁醚等，它们腐蚀性基本不强，因此均可选用普通不锈钢，具体选用时还应根据介质的属性和相关要求做出合理选择。另外值得注意的是酮、酯、醚对多种橡胶有溶解性，在选择密封材料时避免出错。 还有许多其它介质不能在此一一介绍，总之在选材时切不可随意和盲目，应多查阅相关资料或借鉴成熟经验。 2、密封问题：无泄漏是化工设备的永远追求，正是这种要求促成了磁力泵的应用日益扩展。然而真正做到无泄漏还有很长的路要走，比如磁力泵隔离套的寿命问题、材料的孔蚀问题、静密封的可靠性问题等等。现就密封方面的一些基本情况简单介绍如下： 1）密封形式：对于静密封来说，通常只有密封垫和密封圈两种形式，而密封圈又以O型圈应用最广；对于动密封，化工泵很少采用填料密封，以机械密封为主，机械密封又有单端面和双端面、平衡型和非平衡型之分，平衡型适用于高压介质的密封（通常指压力大于1.0MPa），双端面机械密封主要用于高温、易结晶、有粘度、含颗粒以及有毒挥发的介质，双端面机械密封应向密封腔中注入隔离液，其压力一般高于介质压力0.07～0.1MPa，单端面机械密封具有安装维护简便，无需加入冷却隔离液，价格适中等优点，是化工泵中运用很广泛的一种动密封形式。 2）密封材料：化工磁力泵静密封的材料一般采用氟橡胶，特殊情况才采用聚四氟材料；机械密封动静环的材料配置较为关键，并不是硬质合金与硬质合金对磨就{zh0}，价格高是一方面，两者没有硬度差也并不合理，所以{zh0}根据介质特点区别对待，我公司机械密封的对磨面有碳化硅对四氟（基本配置）、碳化硅对碳化硅、氧化铝陶瓷对四氟、碳化硅对氧化铝陶瓷、硬质合金对硬质合金等供用户选择配置使用。 3、粘度问题：介质的粘度对泵的性能影响是很大的，当粘度增加时，泵的扬程曲线下降，{zj0}工况的扬程和流量均随之下降，而功率则随之上升，因而效率降低。一般样本上的参数均为输送清水时的性能，当输送粘性介质时应进行换算（不同粘度的修正系数可查阅相关换算图表）。对于粘度较高的浆类、膏类及粘稠液的输送，建议选用砂浆泵，我公司的UHB-ZK耐腐耐磨砂浆泵即可适用于有粘度或带颗粒的腐蚀性介质。 二、泵选型原则：设计院在设计装置设备时，要确定泵的用途和性能参数并选择泵型。 这种选择首先得从选择泵的种类和形式开始，那么以什么原则来选泵呢？依据又是什么？1、使所选泵的型式和性能符合装置流量、扬程、压力、温度、汽蚀余量、吸程等工艺参数的要求； 2、必须满足介质特性的要求，对输送易燃、易爆有毒或贵重介质的泵，要求轴封可靠或采用无泄漏泵，如磁力驱动泵（无轴封，采用隔离式磁力间接传动），对输送腐蚀性介质的泵，要求对流部件采用耐腐蚀性材料，如氟塑料耐腐蚀泵，对输送含固体颗粒介质的泵，要求对流部件采用耐磨材料，必要时轴封用采用清洁液体冲洗； 3、机械方面要求可靠性高、噪音低、振动小； 4、正确计算泵采购的投入成本。详见：如何正确计算采购泵的投入成本。 三、基本泵的选型参照： （一）、下面是基本泵的选型方法： 1、输送强腐蚀性介质（如“浓硫酸、浓硝酸”）时、输送易燃易爆介质时、使用环境不得有任何污染时——可选用磁力泵，如“CQB系列磁力泵、IMD系列磁力泵，如需自吸——可选用ZMD系列磁力泵； 2、IHF离心泵及FSB离心泵具有转速高、体积小、重量轻、效率高、流量大、结构简单、输液无脉动、性能平稳、容易操作和维修方便等特点，如使用工况无特殊要求时、——选用离心泵较好； 3、输送含固体颗粒化学介质的泵，要求对流部件采用耐磨材料时——砂浆泵为{zj0}选用对象，UHB-ZK耐腐耐磨砂浆泵材料为高强度新型工程塑料UHBWPE，它是一种改性的超高分子量（500万以上）聚乙烯。在塑料中，它具有{zy}异的耐磨性，实验对比，它的耐磨性能远远高于不锈钢，且耐冲击、抗蠕变性和{jj0}的耐腐蚀性（与F4相当），还有无粘附性等独特性能； 4、当介质液面在泵安装位置的下方时——应选用FZB自吸泵，如还需满足防漏的特性——可选用ZMD磁力式自吸泵。 （二）、根据泵的性能曲线图选择{zj0}规格型号当使用要求在性能参数表中找不到适合的型号时——可参照泵的性能曲线图选择最适合的泵型。

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原文：
Petroleum, chemical industry in the national economy occupied a very important position, chemical process pump devices as a key supporting more and more people's attention. Because the characteristics of complex chemical medium, combined with environmental protection and the equipment is ever increasing energy consumption, the chemical manufacturer, chemical pump how we should conduct selection? Attention should be focused on what? ... And so it is particularly important. Most chemical companies are combining the characteristics related products to the selection of the commonly used chemical pump do some brief comments, hope to benefit our customers in this area work better. First, fluorine plastic pump selection should consider the following questions: 1, corrosion problems: a long time, chemical equipment corrosion is one of the most troublesome damage, a little careless, at worst damage to the device, while in the accident or accidents. According to statistics, chemical equipment, about 60% of the damage caused by erosion, so when the first selection in the chemical pump to pay attention to the scientific selection. Usually there is a misunderstanding, that stainless steel is the "Universal", no matter what the media and environmental conditions is offering stainless steel, this is very dangerous. Below for some commonly used chemical medium to talk about the selection of points: 1) sulfuric acid: As one of the strong corrosive medium, sulfuric acid is the use of a very wide range of important industrial raw materials. Sulfuric acid concentration and temperature corrosion of materials vary greatly, for more than 80% concentration, the temperature below 80 ℃ of concentrated sulfuric acid, carbon steel and cast iron has better corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid , not used as a valve material; ordinary stainless steel such as 304 (0Cr18Ni9), 316 (0Cr18Ni12Mo2Ti) have limited use of the sulfuric acid. Therefore, sulfuric acid delivery valve is usually high silicon cast iron (casting and machining difficult), high alloy stainless steel (Alloy 20) manufacturing, but the process is difficult and expensive, so people are not optimistic. Fluorine plastic alloy with good resistance to sulfuric acid good performance, it is the Shanghai Institute of Organic Chemistry, Chinese Academy of patent material, the company introduced in 1985, patented technology, first with the development and production of corrosion-resistant chemical pumps, proved by the Chinese Academy of Sciences, has not yet found within the temperature range which can react with the chemical medium, so using fluorine pump (F46) is a more economical choice. Company applies to products: CQB fluorine plastic magnetic pumps, IMD fluorine magnetic pump, IHF fluorine pump, FSB fluorine alloy pump and so on. 2) HCl: Most decisions are tiring of hydrochloric acid corrosion of metallic materials (including stainless steel), containing molybdenum high silicon iron are only available for 50 ℃, 30% less hydrochloric acid. And metal materials contrary, the vast majority of non-metallic materials on the hydrochloric acid has good corrosion resistance, so the pump and the rubber lined plastic pumps (such as engineering plastics, fluorine plastic, etc.) is best transport options hydrochloric acid. Company applies to products: CQB fluorine plastic magnetic pumps, IMD fluorine magnetic pump, IHF fluorine pump, FSB fluorine alloy pump, UHB polyethylene centrifugal pumps and so on. 3) nitrate: common metal in nitric acid was most rapid corrosion damage to stainless steel is the most widely used nitric acid-resistant materials, all concentrations of nitric acid at room temperature have good corrosion resistance, it is worth mentioning that the stainless steel containing molybdenum ( such as 316,316 L) of nitric acid corrosion resistance is not only no better than ordinary stainless steel (eg 304,321), and sometimes even better. For high-temperature nitric acid, usually fluorine plastic alloy. Company applies to products: CQB fluorine plastic magnetic pumps, IMD fluorine magnetic pump, IHF fluorine pump, FSB fluorine alloy pump and so on. 4) acetic acid: it is the most corrosive substances in organic acids, one of ordinary steel in all the acetic acid concentration and temperature will be severe corrosion, acid-resistant stainless steel is an excellent material, but also 316 stainless steel containing molybdenum for high temperature and dilute acetic acid vapor. For the high temperature and high concentration of acetic acid or other corrosive media containing such stringent requirements may make use of high alloy stainless steel or fluorine plastic pumps. If CQB fluorine plastic magnetic pumps, IMD fluorine magnetic pump, IHF fluorine pump, FSB fluorine alloy pump and so on. 5) alkali (sodium hydroxide): General corrosion is not very strong, but generally will have a crystalline alkali solution, it can be used configure the silicified graphite mechanical seal material 169, centrifugal pumps and FSB IHF fluorine fluorine alloy pump. 6) ammonia (ammonium hydroxide): most of the metal and nonmetal in liquid ammonia and ammonia (ammonium hydroxide) in the corrosion were slight, not only the use of copper and copper alloys. Most of our products suitable for the delivery of ammonia and ammonia. Such as fluorine plastic magnetic pumps, plastic centrifugal pumps fluoride can be used long-term stability. 7) salt water (sea water): ordinary steel in sodium chloride solution and sea water, salt water corrosion rate is not high, are generally required to use paint protection; all kinds of stainless steel has a very low corrosion rate, but may be caused by partial chloride of corrosion, typically 316 stainless steel is better. Companies can apply various types of chemical pumps. 8) alcohols, ketones, esters, ethers: Common alcohols media are methanol, ethanol, ethylene glycol, propanol, etc., ketones medium with acetone, methyl ethyl ketone, etc., there are a variety of methyl esters of medium , ethyl ester, ether medium with ether, ethyl ether, butyl ether, etc., they basically do not corrosive, and therefore may use an ordinary stainless steel, the specific use of the property should also be under the media and related requirements to make reasonable choices. Also noteworthy was the ketone, ester, ether on a variety of rubber are soluble, the choice of sealing materials to avoid mistakes. There are many other media can not be introduced in the 11, when a word must not be arbitrary in the selection and blind, should be more access to relevant information or learn from mature experience. 2, sealing problems: No leakage is always the pursuit of chemical equipment, it is this requirement led to expanding the application of magnetic pump. But really no leakage is still a long way to go, such as magnetic pump isolation sets of life issues, pitting the material issues, and so the reliability of static sealing. The closed area are some basic brief is as follows: 1) Seal type: For static sealing, usually only two types of gaskets and seals, and O-ring seals Youyi the most widely used; for dynamic sealing, chemical pump seal packing seldom used to seal the Lord, there are single mechanical seal face and double-end, balanced and unbalanced type of points, balanced medium suitable for high pressure seal (usually a pressure greater than 1.0MPa), double mechanical seal is mainly used for high temperature, and crystallization with viscosity, with particles and toxic volatile media, double mechanical seal cavity should be sealed into the isolation liquid, the pressure is generally higher than the medium pressure of 0.07 ~ 0.1MPa, single mechanical seal with the installation and maintenance is simple, without adding cooling insulating liquid, affordable, is one of very broad use of chemical pumps in a dynamic seal forms. 2) Sealing material: Chemical static magnetic pump seal materials generally used fluorine rubber, special circumstances, it uses PTFE material; mechanical seal ring material static configuration is more critical, not the carbide and carbide on the wear on the best , high price on the one hand, the hardness difference between the two is not too unreasonable, so the best features of discrimination under the media, our mechanical seal with silicon carbide on the wear surface on the PTFE (basic configuration), Silicon carbide on silicon carbide , alumina ceramic Teflon, silicon carbide on alumina ceramic, carbide and other hard alloy on the configuration used for the user to choose. 3, the viscosity issue: medium viscosity on pump performance impact is great, when the viscosity increases, the pump head curves down, the best conditions of the head and the flow were decreased, while the power is followed increased, thus reducing efficiency. Sample of the general parameters of the performance when both transport water, should be carried out when handling viscous media conversion (different viscosity correction factor can be found related to conversion chart). For high viscosity slurries, pastes and viscous fluid type transmission, suggested the use of mortar pump, my company UHB-ZK corrosion resistant mortar pump can be applied to a viscosity or with particles of corrosive media. 2, pump selection principle: Designing Institute equipment in the design of devices to determine the use and performance parameters of the pump and select the pump type. This option must first select the pump from the type and form of the beginning, then what does the principle of selecting a pump? Based on what? 1, so that the selected pump type and performance meet the plant flow, lift, pressure, temperature, NPSH, suction process parameters such requirements; 2 medium properties must meet the requirements of transporting inflammable, explosive or toxic media expensive pumps, required a reliable seal with no leakage or pump, such as magnetic drive pump (no seal, with isolated magnetic indirect transmission), corrosive medium on the transmission pump, required convective parts are corrosion resistance material, such as fluorine plastic corrosion pump, solid particles on the transport medium with the pump flow required parts abrasion-resistant material used, if necessary, seal flush with the use of cleaner liquid ; 3, mechanical requirements, high reliability, low noise and vibration; 4, the correct calculation of the input pump purchase cost. See: How to correctly calculate the cost of procurement into the pump. Third, the basic Pump Selection Reference: (A), the following is the basic Pump Selection Method: 1, transport corrosive media (such as "concentrated sulfuric acid, concentrated nitric acid"), the transport flammable and explosive medium, the use of the environment without any pollution - optional pump, such as "CQB Series Magnetic Pump, IMD Series Magnetic Pump, For self-absorption - can be used ZMD series magnetic pump; 2, IHF and FSB centrifugal pump with high speed, small size, light weight, high efficiency, traffic flow, simple structure, no pulse infusion, steady performance, easy operation and convenient maintenance, such as the use of condition No special requirements when, - used pump well; 3, transport medium containing solid particles of chemical pumps, required parts are wear-resistant materials convection - mortar pump is the best choice object, UHB-ZK corrosion resistant materials for high-strength mortar pump new engineering plastic UHBWPE, it is a kind of modified ultra high molecular weight (500 million or more) of polyethylene. In plastic, it has the most excellent wear resistance, experimental contrast, its wear resistance is much higher than stainless steel, and impact resistance, creep resistance and excellent corrosion resistance (and quite F4), there are no unique properties such as adhesion; 4, when the medium level in the pump when the lower mounting location - should be used FZB pump, such as the characteristics needed to meet the leak-proof - can be used ZMD magnetic type pump. (B), according to the pump performance curve to select the best standard model when using the performance parameters required for the model can not find the table when - can refer to the pump performance curve to select the most appropriate pump type.