阀门维修及保养方法

阀门维修及保养方法

多年的阀门维修过程中，江阴市欧雷斯对阀门的损坏认为;大部分的起因多是缺乏防护意识，对使用中的阀门几乎没有定期进行保养性阀门修理，一直到阀门损坏严重，严重不符合生产要求后才进行阀门更换或阀门检修，对生产有着不良的负面影响！以下是欧雷斯阀门维修厂综合各类阀门维修信息，对阀门维修及保养方法提供以下建议：希望对阀门使用单位及阀门维修单位有所帮助：

一、阀体锈蚀与防护

阀体(包罗阀盖)，占了阀门的大局部分量，又处在与介质的常常接触中，所以选用阀门，往往从阀体资料动身。

阀体的锈蚀不过两种方式，即化学锈蚀和电化学锈蚀。它的锈蚀速度决议于介质的温度、压力、化学功能以及阀体资料的抗锈蚀才能。锈蚀速度分为六等：

1、完全耐蚀：锈蚀速度低于0.001毫米/年；

2、极耐蚀：锈蚀速度0.001至0.01毫米/年；

3、耐蚀：锈蚀速度0.01至0.1毫米/年；

4、尚耐蚀：锈蚀速度0.1至1.0毫米/年；

5、耐蚀性差：锈蚀速度1.0至10毫米/年；

6、不耐蚀：锈蚀速度大于10毫米/年。

阀体的防锈蚀，首要是准确选用资料。固然防锈蚀的材料非常丰厚，但可否选得得当，照样不轻易的工作，由于锈蚀的问题很复杂，例如硫酸在浓度低时对钢材有很大的锈蚀性，浓度高时则使钢材发生钝化膜，能防锈蚀；氢只在高温高压下才显示对钢材的锈蚀性很强，氯气处于枯燥形态时锈蚀功能并不大，而有必然湿度时锈蚀功能很强，很多资料都不克不及用。选择阀体资料的难处，还在于不克不及只思索锈蚀问题，还必需思索耐压耐温才能，经济上能否合理，购置能否轻易等要素。所以必需专心才是。

其次是接纳衬里办法，如衬铅、衬铝、衬工程塑料、衬自然橡胶及各类组成橡胶等。如介质前提答应，这却是一种节省的办法。

再次，在压力、温度不高的状况下，用非金属做阀门主体资料，往往能非常有用地防制锈蚀。此外，阀体表面面还遭到大气锈蚀，普通钢铁资料都以刷漆来防护

阀体的锈蚀损坏，首要是锈蚀介质惹起的；但是阀杆锈蚀景遇分歧，它的首要问题倒是填料。不单锈蚀介质能使阀杆锈蚀损坏，并且普通的蒸气和水也能使阀杆与填料接触处发生斑驳。尤其成问题的是，保管在仓库里的阀门，也会发作阀杆点锈蚀；即便不锈钢阀杆也难防止。这是为什么？这就是填料对阀杆的电化学锈蚀。

目前运用最广的填料是以石棉为基体的盘根，如石墨石棉盘根、油浸石棉盘根、橡胶石棉盘根。石棉资料中含有必然时的氯离子，此外还有钾、钠、镁等离子，石墨中又含有硫化铁等杂质，这些都是锈蚀的要素。氯离子能穿透金属外表的钝化膜，使锈蚀不时进行下去。其他杂质的存在，也有助于锈蚀的进行。水和蒸气是导电物质，能使电化学锈蚀的电路进一步沟通。仓库里的阀门，也由于填料湿润，或空气湿润，发生电化学锈蚀。别的，填料与阀杆之间缺乏氧气，跟四周比拟，存在着氧的浓度差，这就组成了氧浓差电池，成为又一种电化学锈蚀的方式。

在阀门维修行业中，人人都知道，阀杆往往采用优质材料，它的锈蚀损坏是很惋惜的，且影

响出产，所以必需接纳防腐办法。

可以接纳的办法有：

（1）阀门保管时期不要加填料。不装填料，落空了阀杆电化学锈蚀的要素，可以长时间保管而不致被锈蚀。

（2）对阀杆进行外表处置。如镀铬、镀镍、渗氮、渗硼、参锌等。

（3）削减石棉杂质。用蒸馏水洗濯的方法，可以降低石棉中的氯含量，然后降低其锈蚀性。（4）在石棉盘根中加缓蚀剂。这种缓蚀剂能按捺氯离子的锈蚀性。如亚硝酸钠。

（5）在石棉中加牺牲金属。这就是一种比阀杆电位更低的金属来作牺牲品。如许，氯离子的锈蚀就起首对牺牲金属发作，然后维护阀杆。可作为牺牲金属的有锌粉等。

（6）采用聚四氟乙烯维护。聚四氟乙烯有优秀的化学不变性和介电功能，电流不克不及经过，如将石棉盘根浸渍聚四氟乙烯，锈蚀便将减小。也可用聚四氟乙烯生料带包裹石棉盘根，然后装入填料函。

（7）进步加工光亮度，也能减轻电化学锈蚀。

三、阀门封闭件锈蚀与防护

封闭件常常遭到流体的冲刷，使得锈蚀加速开展。有些阀瓣，固然采用较好资料，但锈蚀损坏仍比阀体快。

上下封闭件与阀杆、阀座常用螺纹衔接，衔接处比普通部位缺氧，轻易组成氧浓差电池，使其锈蚀损坏。有的封闭件密封面采用压入方式，因为共同不紧，稍有裂缝，也会发作氧浓差电池锈蚀。

防护方法：

（1）尽量采用耐锈蚀材料。封闭件分量很小，但在阀门中起伤害，只需可以耐锈蚀，即便采用一点也不妨。

（2）改良封闭件构造，使其少受流体冲蚀。

（3）改良衔接构造，防止发生氧浓差电池。

（4）在200℃以下的阀门中，封闭件衔接处和密封面衔接处，运用聚四氟乙烯生料带作填料，可以减轻这些部位的锈蚀。

（5）在思索耐锈蚀的还，还要留意封闭件资料的抗冲蚀性。要运用抗冲蚀性强的资料作封闭件。

Valve repair and maintenance methods

Valve repair process, the Jiangyin City Oulei Si on the damage to the valve; of most of the causes of the lack of protection awareness on the use of the valve almost no regular maintenance of sexual valve repair, until the valve seriously damaged, seriously do not meet the production requirements after valve replacement or valve repair, have an adverse negative impact on the production! The following is a Oulei Si valve repair plant all kinds of valve repair information, offers the following recommendations to the maintenance of the valve: valve unit and valve

maintenance units to help:

Corrosion of the body, but in two ways, namely, chemical corrosion and electrochemical corrosion.

Its corrosion rate resolution anti-corrosion can be at medium temperature, pressure, chemical

Corrosion: the corrosion rate from 0.01 to 0.1 mm / year;

4, yet corrosion: the corrosion rate from 0.1 to 1.0 mm / year;

5, the corrosion resistance and poor: the corrosion rate from 1.0 to 10 mm / year;

6, no corrosion: the corrosion speed is greater than 10 mm / year.

The body of the anti-corrosion, is the accurate selection of the data. While anti-corrosion material

is very rich, but could be selected properly, still not easy to work due to the corrosion problem is

very complex, such as sulfuric acid in low concentration on the steel corrosion at high concentrations, the steel occurred blunt membranes, can prevent corrosion; hydrogen only at high temperature and pressure display strong on the corrosion of steel in a dry form, the chlorine corrosion feature does not necessarily humidity, corrosion features a strong, a lot of information not grams less than the with. The choice of the difficulty of the body of information, is not only thinking about the problem of corrosion, but also must be thinking of pressure temperature can be whether a reasonable, economic, purchase it easy for elements. So I must concentrate on is. Followed by the admission of the way of lining, such as the lining of lead lining of aluminum, the lining of engineering plastics, the lining of natural rubber and various types of composition rubber. Such as media, the premise of promise, this is a way of saving.

Again, conditions of pressure, temperature is not high, made of non-metallic valve body data is often very useful control corrosion. In addition, the valve body surface was atmospheric corrosion of ordinary steel data protection paint to

Second, the valve stem corrosion and protection

Corrosion damage of the valve body, first aroused by the corrosion medium; but stem rust Jingyu differences, it is the most important issue touches filler. Not only the corrosion medium can stem rust damage, and the ordinary steam and water can make the stem and packing contact took place mottled. Particular problem is that the valves kept in the warehouse, also attack the stem point corrosion; even if the stainless steel stem is also difficult to prevent. Why is that? This is filler on the electrochemical corrosion of the valve stem.

The current use of the most widely used packing is the packing of asbestos as a substrate, such as graphite asbestos packing, oil-immersed asbestos packing, rubber asbestos packing. Inevitable when the chloride ion containing asbestos information, in addition to potassium, sodium, magnesium, and plasma contain impurities such as iron sulfide, graphite, these are the elements of corrosion. The chloride ions can penetrate the passive film of the metal exterior rust from time to time to carry on. The presence of other impurities, and also contribute to corrosion. Water and steam is a conductive material, to enable the electrochemical corrosion of the circuit further communication. Valve in the warehouse, packing moist, or humid air, the occurrence of electrochemical corrosion. Lack of oxygen, filler stem, with four weeks analogy, the existence of oxygen concentration, which form the oxygen concentration cell as an electrochemical corrosion. In the valve repair industry, everyone know, the stem often using high quality materials, corrosion damage is very regrettable, and the effect produced, so to must be accepted by anti-corrosion.

Way that can be accepted:

The valve custody period (1) Do not add filler. Do not install filler dashed stem electrochemical corrosion elements, can be a long custody without being corroded.

content in the asbestos, and then reduce its corrosion resistance.

(4) in the asbestos packing inhibitor. This inhibitor can inhibit the corrosion of chloride ion. Such as sodium nitrite.

(5) plus the expense of the metal in asbestos. This is a metal lower than the stem potential victim. Such as the promise of chloride ion corrosion chapeau to the expense of metal attack, and then to maintain the stem. Can be used as the expense of the metal have zinc powder.

(6) the use of PTFE maintenance. PTFE have excellent chemical invariance and dielectric function, the current can not be after, such as asbestos packing impregnated with PTFE, rust put decreases. Can also be used Teflon tape wrapped asbestos packing, and then load the stuffing box.

(7) progressive processing brightness, but also to reduce the electrochemical corrosion.

3, the valve closed pieces of corrosion and protection

Closed often been fluid, erosion, corrosion accelerated to carry out. Some valve, of course, better information, but the corrosion damage is still faster than the body.

Up and down the closed parts and valve seat commonly used thread convergence, convergence at the lack of oxygen than ordinary parts, easily form the oxygen concentration cell corrosion damage. Some closed sealing surface indentation, because the common is not tight, a slight crack, will attack the oxygen concentration cell corrosion.

Protection methods:

(1) maximize the use of resistance to corrosion of materials. Closed parts component is small, but the valve since the injury, only resistant to corrosion, even with a little may also wish to.

(2) improvement of closed structure, making it less susceptible to fluid erosion.

(3) improved convergence structure, to prevent the occurrence of the oxygen concentration cell.

(4) valves below 200 ℃in the closed connection between the sealing surface on connection with the use of Teflon tape as a filler can reduce the corrosion of these parts.

(5) In thinking about the resistance to corrosion, but also pay attention to the erosion resistance of closed pieces of information. Use of erosion resistance data for closed parts