butadiene rubber resistant to 80 degrees Celsius below oil, fluorine rubber resistant to 150 degrees Celsius below various corrosive medium ) three stacked PTFE ring ( resistant to 200 degrees Celsius below the strong corrosive medium ) nylon bowl shaped ring ( resistant to 120 degrees Celsius below ammonia, alkali ), forming filler. In ordinary asbestos packing outside, coated with a layer of Teflon belt, can improve the sealing effect, relieve stem electrochemical corrosion. In packing, valve stem to rotate at the same time, in order to keep around evenly, and to prevent too much death, tighten the cap evenly, Do not tilt. Section second maintenance On valve maintenance, can be divided into two kinds of circumstances; one is the preservation, another is the use of maintenance. ( a ) maintain Keeping maintenance purposes, is not that the valve in the custody of the damage, or lower quality. But in fact, improper keeping is one of the important reasons for the damage of the valve. The valve should be arranged in good order, storage, small valve on the shelf, valves in the storehouse surface with regular arrangement, not a disorderly pile, don't let the flange joint surface in contact with the ground. This not only in appearance, is mainly protects the valve from damage. The safekeeping and improper handling, hand wheel broken, stem touch askew, the handwheel and the stem of the fixed nut loose loss etc, these unnecessary losses,

should avoid. On the short term not used valves, should remove the asbestos packing, in order to avoid electrochemical corrosion, damage to the valve stem. Just into the library of the valve, to check, such as during transport into the water or dirt, to wipe clean, and storage. 、The valve import and export use waxed paper or plastic sheet to seal, to prevent in dirty things. 、On the energy in the atmosphere rusted valves processing surface antirust oil, to protect. 、Outside of the valve, must be covered with linoleum or tarpaulin, rainproof, dustproof articles. Warehouse storage valve should be kept clean and dry. 、( two) the use of maintenance 、The purpose is to use and maintenance, prolonging the service life of the valve and assure reliable opening and closing. 、Threaded stem, often with a stem nut friction, to apply a little oil or graphite, molybdenum disulfide, Huang Gan, play the role of lubrication. Not frequent opening and closing valves, also to regularly rotate the handwheel, the stem threads add lubricant, in order to prevent the bite. The outdoor valve, to stem with protective sleeve, with rain, snow, dust, rust. Such as valves machinery to move, to the gearbox to add lubricating oil. To keep the valve cleaning. Always check and keep the valve parts integrity. If the hand wheel fixing nut off, to complete, cannot

use makeshift, otherwise it will Mill Park the upper valve stem Quartet, gradually lost with reliability, can't even start. Do not rely on the valve support other weights, never on valve stand. The valve stem, in particular the threaded portion, must often wipe, the dust dirty lubricant should be replaced with a new, because the dust containing hard sundries, easy to wear thread and the surface effect, service life. Section third operation For the valve, not only will install and maintain, but also can operate. ( a ) manual valve Manual valve is the most widely used valves, the hand wheel or the handle, is in accordance with the ordinary human design, considering the sealing surface strength and necessary closing force. Therefore cannot use the long lever or long board hand. Some people accustomed to the use of plate in hand, should strict attention to, not too big too fast, otherwise easy to damage the sealing surfaces, or board broken hand wheel, handle. Open and close the valve, forced should smooth, no impact. Some impact to open and close the high-pressure valve components have taken into account the impact force

and the general valve can gang. For the steam valve, open before, should advance heating, and the exclusion of condensed water, when open, should try to slow, so as to avoid the phenomenon of

water hammer. When the valve is fully open, should be overturned a handwheel, so that the thread tightly, so as to avoid looseness damage. For rising stem valve, to remember the full open and full closed position of the valve stem, avoid the full impact of top dead center. And easy to check whether the normal closed. If the valve does shedding, or sealing of the spool is embedded between larger sundries, the fully closed position of the valve stem to change. At the beginning of the internal pipeline, waste more, the enlight, uses the medium to high speed flow, washes it off, and then gently closed ( not quickly closed, a closed, to prevent residual impurity pinch sealing surface), open again, so repeated several times, wash the dirt, and then into the normal work. Normally open valve, sealing surface dirt may stick, close when you want to use the method to make it clean, and then officially closed. If the hand wheel, the handle is damaged or lost, should be immediately installed is not available, the active plate hand instead, so as not to damage the valve stem Quartet, opening and closing is ineffective, resulting in the production of accident. Some media, in the valve closed after cooling, so that the valve part shrinkage, operators should be at proper time off for another time, let the sealing surface without seam, otherwise, medium from the slit high speed flow, easy erosion sealing surface. During operation, such as found in operation too difficult, should analyze the reason. If the fill too tightly, may be appropriate to relax, such as a valve stem skew,

should inform the staff repair. Some valves, in the closed state, the closure member expands when it is heated, causing the opening is difficult; if must now be opened, the valve cover is screwed loose half circle to the circle, eliminating stem stress, then moving the hand wheel plate. ( two) note In 1, more than 200 DEG C high temperature valve, because the installation at room temperature, and after normal use, temperature rise, heat expansion bolt, increase a gap, so must be tightened again, called" hot tight", the operation staff should pay attention to this work, otherwise prone to leaking. In 2, when the weather is cold, the water valve closing stop valve should be long, after removing ponding. Steam valve steam stop, also to drain condensed water. The bottom of the valve as the plug, it can be open drainage. In 3, a metal valve, some hard and brittle, some low intensity, operation, opening and closing force can not be too large, especially not so fierce. Also note that monarch free object collision. In 4, the new valve when in use, packing pressure should not too tight, not leakage, so as not to stem pressure too big, accelerate wear, and open and close it

 

第二篇：英语

好了，言归正传在开始方法讲述的时候，请先回答我一个问题：是不是还在捧着单词书背呢？如果你的答案是的话，有没有突破A的魔掌呢？如果你胸有成竹的告诉我：我已经背到B了，那么，现在，孩子，听我的话，放下单词书，立地成佛。如果你仰着你微红的小脸说，我没背下来或者是我还在准备开始背的话，那么我下面的话会让你欢欣不已不要再背单词书了，那么，你要问我，不背单词书，我都不认识，怎么考四级呢？好了，请接着看我下面的话，不要跨区，要认真看。现在，我们一起来回忆一下中国四六级的发展史，考了这么多年你有没有听说一年一个大变化呢？有没有说每年一个改革从题型到词汇要求通通和原来的不一样？答案是，没有！为什么没有？你可以想一下，如果真是那样做的话，是不是说明出题组每一年都搬起一块大石头狠狠的砸自己脚一下呢？出题组也是人，谁都要面子的是不是？所以，我们得出的结论是，从题型，到词汇要求，尤其是词汇要求，其实都是没有怎么变过的。那好，我们下一个问题就是，就算它不变，我们还是不知道他要考的是那些啊。好，我们接着分析，我们拿十年作为一个时间段，每年两次，一共二十次，词汇要求就那么多，那么，重复率就不是一般的高啊孩子，今年考阅读的明年搬到翻译里去考，明年考听力的搬到词汇去考，就是这样啊，所以呢，这里就引出了我们复习四级的方法---真题。最大范围内玩烂四级！总之一句话，真题是王道！接下来，有人可能会说，我真题早就在老师的带领下做完了，也讲完了，我都开始做模拟了！好了，我先要问一句，孩子你四级是不是就只是想过，能上五百就会高兴不已啊？以笔者的经验，在考英语专四的时期，最认真对待的就是真题了，除却真题其他一概本着不会的词不查，错过的题不看，唯一对于真题是看了又看，总结再总结，结果某小伙已经知道了，非常如人意，非常非常如人意是不是？所以，这里给你的方法绝不是空穴来风。好了，经过上面的洗脑你已经知道了我们的真题才是我们最爱的人了，那么我们要怎么用它呢？(一)词汇然不背单词书我们到那里去背单词呢，答案是，真题。现在拿出来一套真题，你能告诉我你认识其中多少单词么，大部分都是做完之后标完单词的意思就算做完了吧。同学，这个习惯非常不好。现在，拿出你的真题，从听力开始，查出你不认识的单词，总结在本上，阅读，词汇，可以分项总结下来。那么好，你又要问我，这么多单词，我得查到什么时候，20xx英语四考试全攻略这是我们下面要讨论的问题，我们这里讨论的是词汇的选择及背诵方法。我们广大中的中学生向来有着优良的传统恶习---即边背单词边在本上划拉。这种陋习我们一定要克服！现在洗洗头发，喝杯冰水冷静一下，我们都知道，在考试中只有翻译和写作两项用到写的英语，那也就是说，其他 的

80%的单词只要我们认识就可以了是不是？认识到这个问题的结症所在，我要你知道的是，对于单词，我们只要做到看到它能反映出来意思就行。这是其一。其二是背诵方法，这里我们需要一个洁净的笔记本。每一页都对折。格式按如下这样做书的左半边书的右半边单词释义ANTIBIOTIC n 抗生素背 的时候我们一定要挡住右边，来看左边，如果五秒内你还反映不上来这个单词的意思的话，就看意思。这样一遍遍的看，记住，我们要的是背的遍数而不是背的时间长短。我们不需要笔，我们需要的是脑子！笔者利用这种方法每日可背下300新单词，复习500旧单词。所以，相信我的方法，它绝对是

有科学依据的。（听力）听力怎么办，为了这么一个SB四级考试我们是不是要从头开始练习呢？答案是，绝对绝对不需要！我们要的是绝对的针对考试的训练。我们唯一需要的就是---真题。现在，去图书馆借本新的，或者再买一本。从头再听一遍，要听整套的题哦！不能说我一天听一小部分！听完之后对答案，你会发现你还是错那么多，除了那些记得答案而不是听明白的。这是为什么呢原因就是，我们优秀的中国学生一向都懒于总结的。但是，我已经将学习的强度最小化了，你一定要仔细的听我的话练习。做完之后自然要改答案，改完之后呢，还记得我的话么，我们要玩烂四六级。所以，翻到听力的文本部分，把答案出现的地方画出来，确定到某一句，某一个关键词，这时，我们上面讲的总结单词的方法就用到的，我们不是漫无目的的总结，而是有根据有目标的总结，也就是说，词汇的总结是伴随的做题的过程来的，而不是单独拿时间来做它。划完答案之后要怎么做呢，还没完，再听一遍原题，感受一下答案即将出现的美妙感觉吧。做几套题你就会发现，当答案快要出现的时候，我们的心跳就像马上要见到初恋情人般雀跃而激动了---孩子啊，这就是传说中的语感加题感啊！之后呢，还没完，听力的时候我们呢还是有要求的，那就是用软件听。我们都知道每台电脑有有一款播放软件叫Windows media player 虽然我们通常用千千来代替，但是，这里，我们就用WIMDOWS. 现在，打开Windows media player 的页面，在左上角有一个选项叫做正在播放好了，右键单击它，会有一个选项叫做增强功能其中有一个选项叫做播放速度设置好了，我们就要它，正常情况下它的设置为1.0，但是我们听的时候，把它往右拉，调到1…2或者更快，着取决于你的适应能力，不要质疑，也不要说，你听力好你这么练，我听力差我正常情况下我都听不懂！我告诉你，牛x听力都是这么逼出来的，你听过1.2倍速的时候再听1.0倍速就好像玩一样。听我的，你一定牛！每一套题，我们就用1.2倍速练，你会感受到它的神奇魔力的！如果质疑的话，请看看这标题，特刊！什么叫特刊！就是专为某些人写的，不是为我自己！你可以相信我对你英语底子的了解程度。（二）阅读 笔者在上一次考六级的时候，阅读发挥了平均最低水平--错了两个。但绝对不是因为过万的词汇量的帮助，很大程度上是由于笔者优良的偷懒阅读方法，而且这个方法很具有普适性，而且经过实战的考验，绝对值得采用！在这之前我要讲一下我们国内考试的优良传统，那就是，除了极特别的情况下，出题顺序与文章答案顺序出奇的保持一致性，这种一致性极大程度的缓解了我们的阅读强度。第二，别忘了单词总结，答案关键句中不认识的单词，题目和选项中不认识的单词！这就我们要的重点！（三）作文看完GRE的论文之后你会发现四六的作文技术含量还不及G的一个开头高。 现在，翻出你真题后面给出的范文，看五篇，就五篇！看看人家怎么开头真么结尾，怎么遣词造句的！学习人家的！别告诉我你的作文一般都能得80多分，我实在质疑你们老师的英语能力，笔者看来，笔者梦中所说的英语句式都比你们范文的复杂。 相信我！我们要学就学最好的！看完范文，勾出自己的模板，无论什么文章都往上套！自己写三篇，你就会有自己的风格了！不要盲目的自信！这非常不好！最后，谈一下关于模拟题的事情，笔者认为“由出题组人参与编写”这种宣传词我能用十种不同的问题攻击它的逻辑漏洞！你知不知道漏题是犯法的！它再真它还是假的，我们为什么要弃真的不用非得追着去用假的！ 我们不做那么赔本的买卖！我们就要最纯粹的！听明白了没有