一、方向和位置
1、 Direction and position
许多阀门具有方向性,例如截止阀、节流阀、减压阀、止回阀等,如果装倒装反,就会影响使用效果与寿命(如节流阀),或者根本不起作用(如减压阀),甚造成危险(如止回阀)。一般阀门,在阀体上有方向标志;万一没有,应根据阀门工作原理,正确识别。截止阀的阀腔左右不对称,流体要让其由下而上通过阀口,这样流体阻力小(由形状所决定),开启省力(因介质压力向上),关闭后介质不压填料,便于检修,这就是截止阀为什么不可安反的道理。其它阀门也有各自的特性。
Many valves are directional, such as stop valve, throttle valve, pressure reducing valve, check valve, etc. If they are installed upside down, the service effect and life (such as throttle valve) will be affected, or they will not work at all (such as pressure reducing valve), or even cause danger (such as check valve). For general valves, there is a direction sign on the valve body; If not, it shall be correctly identified according to the working principle of the valve. The valve chamber of the stop valve is asymmetric from left to right. The fluid should pass through the valve port from bottom to top. In this way, the fluid resistance is small (determined by the shape), and the opening is labor-saving (because the medium pressure is upward). After closing, the medium does not press the packing, which is convenient for maintenance. This is why the stop valve cannot be reversed. Other valves also have their own characteristics.
阀门安装位置,方便于操作:即使安装暂时困难些,也要为操作人员的长期工作着想。较好阀门手轮与胸口取齐(一般离操作地坪1.2米),这样,开闭阀门比较省劲。落地阀门手轮要朝上,不要倾斜,以免操作别扭。靠墙机靠设备的阀门,也要留出操作人员站立余地。要避免仰天操作,尤其是酸碱、有毒介质等,否则很不。 闸门不要倒装(即手轮向下),否则会使介质长期留存在阀盖空间,容易腐蚀阀杆,而且为某些工艺要求所禁忌。同时更换填料不方便。 明杆闸阀,不要安装在地下,否则由于潮湿而腐蚀外露的阀杆。 升降式止回阀,安装时要保证其阀瓣垂直,以便升降灵活。 旋启式止回阀,安装时要保证其销轴水平,以便旋启灵活。 减压阀要直立安装在水平管道上,各个方向都不要倾斜。
The installation position of the valve is convenient for operation: even if the installation is temporarily difficult, the long-term work of the operator should also be considered. It is better to align the valve handwheel with the chest (generally 1.2m away from the operating floor), so that it is easier to open and close the valve. The hand wheel of the landing valve shall be upward and not inclined to avoid awkward operation. The valve of the wall machine and the equipment shall also leave room for operators to stand. It is not safe to operate in the sky, especially with acid, alkali and toxic media. The gate shall not be installed upside down (that is, the hand wheel is downward), or the medium will remain in the bonnet space for a long time, which is easy to corrode the valve stem and is contraindicated by some process requirements. It is inconvenient to replace the packing at the same time. The rising stem gate valve shall not be installed underground, or the exposed valve stem will be corroded due to moisture. The lift check valve shall be installed with its disc vertical to facilitate flexible lifting. When installing the swing check valve, ensure that its pin shaft is horizontal so that it can swing flexibly. The pressure reducing valve shall be vertically installed on the horizontal pipeline, and shall not tilt in any direction.
二、 施工作业
2、 Construction operation
安装施工小心,切忌撞击脆性材料制作的阀门。
Be careful during installation and construction. Do not hit the valve made of brittle materials.
安装前,应将阀门作一检查,核对规格型号,鉴定有无损坏,尤其对于阀杆。还要转动几下,看是否歪斜,因为运输过程中,较易撞歪阀杆。还要阀内的杂物。
Before installation, check the valve, check the specification and model, and identify whether there is damage, especially for the valve stem. Turn it a few times to see if it is skewed, because it is easy to bump the valve stem during transportation. Also remove the sundries in the valve.
阀门起吊时,绳子不要系在手轮或阀杆上,以免损坏这些部件,应该系在法兰上。
When lifting the valve, the rope should not be tied to the handwheel or valve stem to avoid damaging these parts. It should be tied to the flange.
对于阀门所连接的管路,一定要清扫干净。可用压缩空气吹去氧化铁屑、泥砂、焊渣和其他杂物。这些杂物,不但容易擦伤阀门的密封面,其中大颗粒杂物(如焊渣),还能堵死小阀门,使其失效。 安装螺口阀门时,应将密封填料(线麻加铝油或聚四氟乙烯生料带),包在管子螺纹上,不要弄到阀门里,以免阀内存积,影响介质流通。
The pipeline connected to the valve must be cleaned. Compressed air can be used to blow away iron oxide chips, mud sand, welding slag and other sundries. These sundries not only easily scratch the sealing surface of the valve, but also block the small valve to make it invalid. When installing the screw valve, the sealing packing (hemp and aluminum oil or PTFE raw material tape) should be wrapped on the pipe thread, and should not get into the valve, so as to avoid the accumulation in the valve and affect the medium flow.
安装法兰阀门时,要注意对称均匀地把紧螺栓。阀门法兰与管子法兰平行,间隙合理,以免阀门产生过大压力,甚开裂。对于脆性材料和强度不高的阀门,尤其要注意。须与管子焊接的阀门,应先点焊,再将关闭件全开,然后焊死。
When installing the flange valve, tighten the bolts symmetrically and evenly. The valve flange is parallel to the pipe flange, and the clearance is reasonable to prevent the valve from generating excessive pressure or even cracking. Special attention shall be paid to valves with brittle materials and low strength. For valves that must be welded with pipes, spot welding shall be carried out first, then the closing parts shall be fully opened, and then welded.
三、保护措施
3、 Protective measures
有些阀门还须有外部保护,这就是保温和保冷。保温层内有时还要加拌热蒸汽管线。什么样的阀门应该保温或保冷,要根据生产要求而定。
Some valves must also have external protection, which is thermal insulation and cold insulation. Sometimes, hot steam pipelines are added in the insulation layer. What kind of valve should be insulated or cold insulated depends on the production requirements.
原则地说,凡阀内介质降低温度过多,会影响生产效率或冻坏阀门,就需要保温,甚拌热;凡阀门裸露,对生产不利或引起结霜等不良现象时,就需要保冷。保温材料有石棉,矿渣棉、玻璃棉、珍珠岩,硅藻土、蛭石等;保冷材料有软木、珍珠岩、泡沫、塑料等。
In principle, if the medium inside the valve lowers the temperature too much, which will affect the production efficiency or freeze the valve, it is necessary to keep it warm, or even heat it; Cold insulation is required when the valve is exposed, which is unfavorable to production or causes frost and other undesirable phenomena. Thermal insulation materials include asbestos, slag wool, glass wool, perlite, diatomite, vermiculite, etc; Cold insulation materials include cork, perlite, foam, plastic, etc.
四、旁路和仪表
4、 Bypass and instrument
有的阀门,除了必要的保护设施外,还要有旁路和仪表。安装了旁路。便于疏水阀检修。其他阀门,也有安装旁路的。是否安装旁路,要看阀门状况,重要性和生产上的要求而定。
Some valves, in addition to the necessary protection facilities, also have bypass and instruments. Bypass is installed. It is convenient for maintenance of drain valve. Other valves are also installed with bypass. Whether to install bypass depends on the valve condition, importance and production requirements.
五、填料更换
5、 Packing replacement
库存阀门,有的填料已不好使,有的与使用介质不符,这就需要换填料。
For valves in stock, some packings are not working well, and some are inconsistent with the medium used, which requires replacement of packings.
阀门制作厂无法考虑使用单位千门万类的不同介质,填料函内总是装填普通盘根,但使用时,让填料于介质相适应。
The valve manufacturer cannot consider using thousands of different media. The stuffing box is always filled with ordinary packing, but the packing should be suitable for the media.
在更换填料时,要一圈一圈地压入。每圈接缝以45度为宜,圈与圈接开180度。填料高度要考虑压盖继续压紧的余地,现时又要让压盖下部压填料室适当深度,此深度一般可为填料室总深度的10-20%。 对于要求高的阀门,接缝角度为30度。圈与圈之间接缝错开120度。 除上述填料之外,还可根据具体情况,采用橡胶O形环(天然橡胶耐60摄氏度以下弱碱,丁晴橡胶耐80摄氏度以下油晶,氟橡胶耐150摄氏度以下多种腐蚀介质)三件叠式聚四氟乙烯圈(耐200摄氏度以下强腐蚀介质)尼龙碗状圈(耐120摄氏度一下氨、碱)等成形填料。在普通石棉盘根外面,包一层聚四氟乙烯生料带,能提高密封效果,减轻阀杆的电化学腐蚀。
When replacing the packing, press it in circle by circle. The joint of each circle should be 45 degrees, and the circles should be 180 degrees apart. For the height of the packing, it is necessary to consider the space for the continued compression of the gland. At present, it is necessary to let the lower part of the gland press the packing chamber to a proper depth, which can generally be 10-20% of the total depth of the packing chamber. For valves with high requirements, the joint angle is 30 degrees. The joints between circles shall be staggered by 120 degrees. In addition to the above fillers, rubber O-ring (natural rubber resistant to weak alkali below 60 ° C, NBR resistant to oil crystal below 80 ° C, fluororubber resistant to multiple corrosive media below 150 ° C), three piece stacked PTFE ring (resistant to strong corrosive media below 200 ° C), nylon bowl ring (resistant to ammonia and alkali below 120 ° C) and other shaped fillers can also be used according to specific conditions. Wrap a layer of PTFE raw material belt outside the ordinary asbestos packing to improve the sealing effect and reduce the electrochemical corrosion of the valve rod.
在压紧调料时,要同时转动阀杆,以保持四周均匀,并防止太死,拧紧压盖要用力均匀,不可倾斜。
When pressing the seasoning, the valve rod shall be rotated at the same time to keep the circumference uniform and prevent death. The gland shall be tightened with even force without tilting.