XD型油环真空泵的使用手册

真空泵作业指导书一、概述真空泵是一种用于产生和维持真空环境的设备。

本指导书旨在提供对真空泵操作的详细指导，确保操作人员能够正确使用真空泵并保证其安全性。

二、真空泵的分类根据工作原理和结构特点，真空泵可以分为以下几种类型：1. 机械泵：通过机械方式排除气体，如旋片泵、涡轮份子泵等。

2. 涡旋泵：通过离心力将气体排出，适合于高真空条件下的操作。

3. 份子泵：通过份子碰撞将气体排出，适合于超高真空条件下的操作。

4. 气体扩散泵：通过气体扩散原理排出气体，适合于大气压到高真空范围内的操作。

根据具体工作环境和需求，选择合适的真空泵进行操作。

三、真空泵操作流程1. 准备工作a. 确保操作人员已经接受过相关的安全培训并熟悉真空泵的操作原理。

b. 检查真空泵及其附件的完整性和正常工作状态，如有异常情况应及时报修。

c. 确保操作区域清洁整齐，无杂物和易燃物。

d. 确保操作人员穿戴个人防护装备，如手套、护目镜等。

2. 启动真空泵a. 按照真空泵的启动顺序，打开相应的电源开关。

b. 检查真空泵的运行状态，确保其正常工作。

c. 如发现异常情况，应即将住手操作并报修。

3. 真空泵的运行a. 根据操作需求，设置真空泵的工作参数，如压力、流量等。

b. 监控真空泵的运行状态，确保其稳定工作。

c. 定期检查真空泵的温度、压力等参数，如有异常情况应及时处理。

4. 住手真空泵a. 按照真空泵的住手顺序，关闭相应的电源开关。

b. 清理真空泵及其附件，确保其干净整洁。

c. 记录真空泵的运行情况，包括启动时间、住手时间、异常情况等。

四、真空泵的维护保养1. 定期检查真空泵的密封件、滤网等部件，如有磨损或者损坏应及时更换。

2. 清洁真空泵的内部和外部表面，确保其无积尘和杂物。

3. 定期更换真空泵的润滑油，保证其正常润滑。

4. 定期对真空泵进行维修和保养，如更换零件、校准参数等。

5. 根据真空泵的使用情况，制定相应的维护保养计划，并记录维护保养的过程和结果。

真空泵操作规程1描述及功能介绍系统流程图：N1 吸气口；N2 排气口；N3 工作液进口；N4 溢流口；N6/7 总排空口；N5 冷却水进口；N6 冷却水出口。

该液环真空泵系统主要包括泵体（010）和三相电机（030），分离器（080），换热器（130），底盘（140），和管线（160，170，240，260，280）。

被抽入气体由系统入口法兰N1吸入。

被抽气体携带部分泵工作液，从泵通过排气管线（170）排至分离器（080）。

在分离器内汽液分离，气体已被压缩至排气压力，通过法兰口N2排出系统。

通过法兰接口N3，新鲜水补至分离器和泵内，直至达到规定的液位。

分离器内液位由液位计（230）指示，正常液位在分离器中间位置，如果液位升高，通过N4口溢流，如果液位下降50mm ，通过N3口补液，以保证分离器内液位。

排空阀（241）用于彻底排净分离器（080）内的液体。

泵（010）中的液体通过排空阀249排净。

工作液用于形成泵的液环。

工作液通过管线（260），自分离器（080），通过管线（260），流入换热器（130），冷却后通过管线（280）返回泵。

在此过程中，压缩产生的热与随被抽气体带入的热被释放掉。

1．1泵的注液通过N3接口向真空泵系统内注入工作液，此时通过管线（260），换热器（130），管线（280）将泵充液。

直至分离器内液位到达中间位置，充水完成。

15分钟后，重新检查液位（此时平衡已建立）。

N1.161．2启动启动电机（030），打开冷却水阀及系统进气阀门，真空泵即投入运行。

当水环建立起来后，系统进入工作状态。

1．3停车1）停真空泵（010）的驱动电机（030）。

2）关闭吸气阀门，以保证规定的启动状态。

3）关闭冷却水阀门。

停车后，泵（010）和分离器（080）间通过工作液管线（260，280）自动实现液位平衡。

当真空泵放液时，所有相关出口必须打开。

注意：如果要长时间停车（１个月或更长时间），必须放空泵内液体。

液环真空泵操作规程
一、开机前
1、检查机组各连接部位是否松动，有松动必须拧紧。

2、通过供液管路向真空泵内供液冲洗，盘动转子，然后通过循环回
路排出。

3、检查电机转向是否正确。

4、存放期过长的真空泵，在起动前应将真空泵轴承腔内清洗干净，
然后更换润滑脂（3#锂基脂）。

二、开机
1、检查工作供液阀前供液压力是否大于0.05MPa以上，开启工作供
液阀，同时打开轴封供液阀，当自动排液阀有液体流出时，关闭工作供液闸阀。

2、调节轴封闸阀，使轴封供液压力在0.02~0.2MPa之间。

3、打开进气闸阀。

4、直至自动排液阀没有液体溢出时，起动电机，泵运转。

同时打开
工作供液阀，使真空压力表指针接近0MPa。

随着泵吸入绝对压力的下降，指针向负值偏移（0~-0.003MPa之间）。

5、真空泵运行过程中，观察调节圆形气液分离器的密封液位，使液
位处于液位计中间位置，防止泄漏。

三、停机
1、关停电机，关闭工作供液阀与轴封供液阀，打开清洗排液阀，放
空积液。

真空泵操作规程一、概述真空泵是一种关键的实验室设备，广泛用于气体和液体抽取、处理和分析过程中的真空环境的维持。

本文档旨在详细介绍真空泵的操作规程，以确保安全、高效地使用真空泵。

二、安全注意事项1. 使用真空泵前应仔细阅读并理解设备的操作手册。

2. 确保操作区域通风良好，避免有毒气体积聚。

3. 在操作真空泵前，应穿戴适当的个人防护装备，如手套、安全眼镜等。

4. 切勿将真空泵用于不符合规定使用范围的场合。

5. 在操作真空泵时，遵循所有应用国家和地方标准、法规和指导方针。

三、操作步骤1. 准备工作a. 确保真空泵处于合适的位置，稳定地放置在平坦的台面上。

b. 安装所需的管道和附件，确保其紧固、连接良好。

c. 检查电源线和插头是否正常，电源接地是否可靠。

2. 启动真空泵a. 将真空泵的电源线插入正确的插座。

b. 打开电源开关，启动真空泵。

c. 等待真空泵自检完成并达到工作状态。

3. 设定真空度a. 查看真空泵的操作面板或显示屏，找到真空度设定选项。

b. 根据实际需求，设置合适的真空度。

4. 抽取气体或液体a. 将待抽取的气体或液体连接至真空泵的进气口。

b. 打开进气阀门，使气体或液体进入真空泵。

c. 根据实际需求，调整进气阀门的开度。

d. 观察真空泵的工作状态，确保抽取过程正常进行。

5. 停止真空泵a. 当抽取任务完成或需要停止真空泵时，先关闭进气阀门。

b. 关闭真空泵的电源开关，将真空泵彻底停止。

6. 清洁与维护a. 在停止真空泵后，等待其完全冷却后才能进行清洁和维护操作。

b. 使用干净的软布清洁真空泵外表面和附件。

c. 定期检查真空泵的过滤器和密封件，并进行必要的更换。

d. 如有异常情况或故障发生，应立即停止使用真空泵，并联系相关维修人员进行检修。

四、常见问题与解决方案1. 真空泵无法启动解决方案：检查电源线和插头是否正常连接，电源接地是否可靠。

2. 真空度无法达到要求解决方案：检查进气阀门是否未完全关闭，管道连接是否紧固可靠。

真空泵操作规程一、引言真空泵是一种重要的工业设备，广泛应用于各种领域，如制药、化工、电子等。

为了确保真空泵的安全性和高效运行，制定一套操作规程是必要的。

本文将介绍真空泵的操作规程，以确保使用者正确操作，提高工作效率。

二、准备工作在操作真空泵之前，需要进行一些准备工作。

1. 检查设备：仔细检查真空泵的外观是否有损坏，各部件是否完好。

同时，检查电气连接是否安全可靠，电源是否正常。

2. 清洁设备：确保真空泵的工作环境干净整洁，表面无杂物。

清洁设备可以提高真空泵的工作效率，延长使用寿命。

3. 准备工具：准备好适用于真空泵操作的工具，如扳手、螺丝刀等。

工具的选择应与真空泵型号相匹配，以免造成损害。

三、操作步骤根据真空泵的操作规程，下面是一般的操作步骤。

1. 打开电源：将真空泵的电源接通，并检查电压是否符合要求。

2. 检查控制面板：检查控制面板的显示屏，确保各个参数在正常范围内。

3. 打开进气阀：在开始操作真空泵之前，确保进气阀开启。

如果是抽真空操作，则关闭进气阀。

4. 启动真空泵：按下启动按钮，启动真空泵。

此时，应注意观察电机运转是否平稳，有无异常噪音。

5. 监测真空度：通过控制面板上的真空度指示器，监测真空泵的工作状态。

确保真空度在设定范围内。

6. 停止操作：在需要停止真空泵操作时，先关闭进气阀，再按下停止按钮，将真空泵停止运行。

四、安全注意事项在操作真空泵时，需要注意以下安全事项，以确保操作人员的安全。

1. 确保操作人员经过培训，熟悉真空泵的操作规程和安全注意事项。

2. 在操作真空泵时，佩戴适当的个人防护装备，如手套、护目镜等。

3. 禁止随意触摸真空泵的运转部件，以免发生意外伤害。

4. 在停止操作后，应断开电源连接并等待真空泵彻底停止运行后再进行维护和检修。

5. 当发现真空泵有异常噪音、温度过高等情况时，应停止操作，并及时联系维修人员进行检修。

五、维护保养定期进行维护保养是确保真空泵长期稳定运行的重要环节。

第一章真空泵概述一、真空泵简介X型系列真空泵是单级旋片油封式真空泵，适用于低、中真空领域，主要用于抽除空气和其它干燥气体。

它是低、中真空的主要设备之一，它可单独使用，也可成为其它真空泵的前级泵。

真空泵具有运转性能可靠、易损件少、振动小、噪音低、效率高的特点。

X型系列真空泵是引进国外先进技术，易损件选用进口元件或进口材料。

X型系列真空泵完全可替代国外同类产品。

真空泵具有运转性能可靠、易损件少、振动小、噪音低、效率高的特点。

二、真空泵构造X系列真空泵按照旋片式原理运行。

泵体（3）中安装一个偏心转子。

利用离心力推动叶片在转子的槽中向泵腔内壁滑动。

叶片(5)将转子(4)和泵腔内壁之间分隔成几个小腔体。

当腔体跟进气口通道相连时，气体被吸入，在下一次转动中被压缩并且推入油分离器（1）。

压差使油不断的被压进压缩腔体。

油和介质再被释放进入油分离器，在那里由于重力作用经除雾器（11）和排气过滤器（8），与排出的气体分离。

分离出的油在油分离器底部再次被推入压力腔体（油循环）。

无油气体经过排气盖板被释放到大气中。

1.油分离器2.吸气阀3.泵体4.转子5. 叶片6.排气阀7. 注油塞8. 排气过滤器9. 排气嘴10.冷却器 11. 除雾器12. 油窗13. 放油塞14. 油过滤器第二章系统简介一、系统流程1．空气流程1）空气由进气滤清器滤去尘埃之后，经由吸气阀（2）进入真空泵泵体；与润滑油混合，与油混合的空气经过压缩后通过排气阀（6）进入油分离器（1）进行粗分离，再经排气过滤器（8）的精分离，不含油的空气通过排气嘴（9）排入大气。

如空气中含有可凝气体，则打开气镇阀。

2）空气流程中各组件功能说明：A、进气滤清器空气滤清器为干式纸质过滤器，过滤纸细孔度约为10μ左右，通常每1000小时应取下清除表面的尘埃，清除的方法是使用低压空气将尘埃由内向外吹除。

B、吸气阀 (2)避免关闭电源后，叶片（5）逆向旋转。

注意：吸气阀不能作为真空系统止回阀或切断阀使用，吸气阀不能防止油被吸入真空系统。

真空泵作业指导书一、引言真空泵是一种用于抽取气体和产生真空的设备，广泛应用于科研实验、工业生产和医疗设备等领域。

本作业指导书旨在提供对真空泵的操作指导，以确保安全、高效地进行真空泵作业。

二、真空泵概述真空泵是一种将气体抽出容器，从而形成低压或者高真空环境的设备。

根据工作原理的不同，真空泵可分为离心泵、旋片泵、涡旋泵、份子泵等多种类型。

在进行真空泵作业前，应确保熟悉所使用真空泵的类型、特点和工作原理。

三、准备工作1. 确保操作区域干燥、通风良好，避免有害气体积聚。

2. 检查真空泵及其附件是否完好无损，如有损坏或者异常现象应及时报修或者更换。

3. 检查真空泵的电源线是否连接坚固，电源开关是否正常。

四、操作步骤1. 打开真空泵的电源开关，确保电源指示灯亮起。

2. 检查真空泵的油位，如低于标准线，应添加适量的真空泵油。

3. 打开真空泵的进气阀门，确保阀门处于开启状态。

4. 打开真空泵的排气阀门，确保阀门处于关闭状态。

5. 启动真空泵，观察泵的运行状态，如有异常声音或者振动应即将住手操作，并检查故障原因。

6. 根据实际需求，调节真空泵的工作压力，以保持恰当的真空度。

7. 在真空泵工作过程中，应定期检查油位和油质，如有需要，及时更换或者添加真空泵油。

8. 当做业完成时，先关闭真空泵的进气阀门，再关闭电源开关，确保安全停机。

五、安全注意事项1. 在操作真空泵时，应佩戴适当的个人防护装备，如手套、护目镜等。

2. 禁止将易燃、易爆物品放置在真空泵附近，以防发生火灾或者爆炸事故。

3. 在操作真空泵时，应避免过度负荷使用，以免损坏设备或者引起意外。

4. 禁止将有害气体直接排放到室内环境中，应选择合适的排气方式，如通过排气管道排放到安全区域。

5. 在操作真空泵过程中，如发现异常情况，应即将住手操作，并及时报修或者寻求专业人员匡助。

六、维护保养1. 定期清洁真空泵的外壳和附件，保持设备的整洁。

2. 定期更换真空泵油，确保油质清洁，延长设备寿命。

石油行业石油泵使用说明书第一章总则1.1 产品概述石油泵是一种专用于石油行业的设备，主要用于输送原油、炼油过程中的各种介质。

本说明书旨在提供石油泵的正确使用方法和相关注意事项，确保设备的安全、稳定运行。

1.2 产品结构石油泵主要由电动机、泵体、叶轮、机械密封等部件组成。

其中，电动机用于提供动力，泵体负责承载和输送介质，叶轮则起到增压的作用，机械密封保证泵体不泄漏。

第二章安全操作2.1 设备安装2.1.1 确保安装场所稳固平整，且通风良好。

2.1.2 泵体应与基础牢固连接，避免设备晃动和共振。

2.1.3 首次使用前，应仔细检查设备上的所有螺栓、紧固件等是否固定牢固。

2.2 电气安全2.2.1 使用过程中应注意防止电源线被钢丝索、管道等锐利物品损坏。

2.2.2 若发现电动机过热、异响、有异常气味等情况，应立即停止使用并检查电机。

2.3 操作规范2.3.1 在操作前，应确保石油泵的泄压装置处于关闭状态。

2.3.2 操作人员必须熟悉设备的控制面板、运行指示灯等功能。

第三章操作方法3.1 开机与停机3.1.1 开机前，应检查电动机的运行方向是否正确，确保与箭头方向一致。

3.1.2 启动设备时，应逐渐加速，避免冲击和过载。

3.1.3 停机前，应先关闭石油泵的进出口阀门，然后再停止电动机。

3.2 维护保养3.2.1 定期检查电动机的润滑油是否充足。

3.2.2 对于长时间不使用的泵机，应及时对其进行防腐处理。

3.2.3 定期清洗泵体内部的沉淀物和杂质，确保流道畅通。

第四章故障排除4.1 电动机无法启动4.1.1 检查电源线是否连接正常。

4.1.2 检查电动机的保险丝是否烧断。

4.1.3 检查电机是否过热，如有报警，请停机查看原因。

4.2 泵机振动或噪音过大4.2.1 检查泵体与基础连接是否松动。

4.2.2 检查叶轮是否受损或磨损。

4.3 泵机出现漏油现象4.3.1 检查机械密封的紧固程度，适时更换密封件。

4.3.2 检查进出口阀门的密封性能。

液环式真空泵安全操作规程范本一、使用前的准备工作1. 检查设备及周边环境是否符合安全要求，确保设备处于正常工作状态。

2. 确保操作人员已经接受相关的安全培训并具备操作证书。

3. 确保工作区域的通风良好，没有易燃、易爆物品。

4. 检查液环式真空泵的电源线，确保线路正常，并连接到可靠的接地插座上。

二、启动真空泵1. 检查液环式真空泵的液位，确保液体充足并符合工作要求。

2. 检查泵的旋钮及开关，确保处于关闭状态。

3. 将真空泵的电源开关置于“关闭”状态。

4. 检查泵的进气管道是否无堵塞，确保泵能正常吸气。

5. 将真空泵的电源开关置于“打开”状态。

三、正常操作1. 在运行过程中，严禁拆卸或更换液环式真空泵的零部件。

2. 如果发现泵体过热或异常噪音，应立即停止泵的运行并通知相关人员进行检修。

3. 在泵的运行过程中，禁止在泵体周围堆放杂物，以免影响泵的正常散热。

4. 如果需要对泵进行保养、清洁或维修，应先切断电源，并等待泵完全停止运行后再进行操作。

5. 在泵体运行期间，应定期检查泵的工作状态，确保泵正常运行且无泄漏现象。

6. 在泵停止运行后，应切断电源，并等待泵完全停止运行后再进行维护或检修工作。

四、紧急情况处理1. 在发生泵体突然停机或其他无法正常运行的情况时，应立即切断电源，并通知相关人员进行处理。

2. 在泵运行期间，如果发现泵体发生泄漏或冒烟等异常情况，应立即切断电源，并使用相应的灭火器进行灭火。

3. 在泵体运行期间，如果发现有异味、烟雾、火花等异常情况，应立即切断电源，并按照事先制定的紧急应急计划进行处理。

4. 在泵运行期间，如果有人员伤害或感觉不适，应立即切断电源，并进行必要的急救措施。

同时，通知相关人员进行应急处理。

五、维护保养1. 在泵停止运行后，应定期对泵进行维护保养，清洁过滤器、润滑部件等。

2. 定期检查液环式真空泵的密封件，如有损坏或老化应及时更换。

3. 定期检查液环式真空泵的电源线及插头，确保无漏电及损坏现象。

油扩散泵真空泵安全操作及保养规程一、前言油扩散泵真空泵是现代实验室中不可或缺的仪器，具有广泛的应用。

为了确保实验室的安全和工作的顺利进行，本文将详细介绍油扩散泵真空泵的操作规程和保养方法。

二、操作规程1. 准备工作在操作油扩散泵真空泵之前，必须进行一系列准备工作。

首先需要确保仪器所在的环境干燥、通风良好，并保持清洁。

其次，需要将仪器与电源断开连接，以免出现电击的危险。

最后，必须检查仪器是否正常工作并根据情况进行维护。

2. 操作步骤•步骤一：打开油扩散泵真空泵的上盖。

•步骤二：检查油存量，如果油不足需加油。

在加油之前必须先关闭油泵。

•步骤三：查看各个仪器部件是否故障或有其他问题，如果发现问题需要及时处理。

•步骤四：启动真空泵，并停留一段时间以使真空压力降低到所需的值。

•步骤五：开启扩散泵，开始工作。

•步骤六：当结束使用后，关闭扩散泵和真空泵。

•步骤七：处理废弃材料，进行清理。

三、保养规程正确的保养对于延长设备的使用寿命和保持其性能至关重要。

以下是保养油扩散泵真空泵的规程。

1. 给油扩散泵添加油油扩散泵必须时刻保持适量的油，以维持其正常运行。

如果发现油量不足，应及时添加。

2. 清理真空泵真空泵在使用过程中会收集各种棉絮、灰尘和微小碎片。

在使用真空泵前，必须将其清理干净。

可以使用干净的布或者软刷来清除，避免使用湿布。

3. 定期更换电机渗油电机在使用过程中会逐渐渗油，需要定期更换。

一般建议在使用1000小时后进行更换，具体更换时间根据使用情况而定。

4. 检查各个零部件在使用过程中，要经常检查油扩散泵真空泵是否有零部件损坏或者松动，如有必须及时维修或者更换。

同时还要检查电缆、接触开关等是否正常。

四、注意事项油扩散泵真空泵向来被认为是较为安全的仪器，但是操作时还是需要注意以下问题：•避免将有机溶剂进入油中。

•根据使用要求选用适当的真空泵及油扩散泵类型。

•不要将手放入真空泵内部，以防止发生安全事故。

•不要在真空泵边上放置易燃物品。

真空泵作业指导书一、概述真空泵是一种用于抽取气体或气体混合物，从而在容器内建立真空环境的设备。

本作业指导书旨在提供对真空泵的正确操作和维护的指导，以确保其安全运行和延长使用寿命。

二、操作步骤1. 准备工作a. 确保工作区域清洁整齐，无杂物堆放。

b. 检查真空泵的电源线是否完好无损，接地是否良好。

c. 检查真空泵的油位是否在正常范围内，如需要添加或更换油，请参考相关操作手册进行操作。

d. 确保操作人员穿戴好个人防护装备，包括耐酸碱手套和防护眼镜等。

2. 启动真空泵a. 打开真空泵的电源开关，确保电源指示灯亮起。

b. 打开真空泵的电源开关，确保真空泵开始运行。

c. 观察真空泵的运行情况，确保无异常噪音和振动。

3. 建立真空环境a. 打开容器的进气阀门，确保气体能够进入真空泵。

b. 观察真空泵的压力表，确保压力逐渐下降。

c. 根据需要，适时调整真空泵的工作参数，如抽气速率和抽气时间等。

4. 关闭真空泵a. 关闭容器的进气阀门，停止气体进入真空泵。

b. 观察真空泵的压力表，确保压力稳定在所需范围内。

c. 关闭真空泵的电源开关，停止真空泵的运行。

d. 清理工作区域，将真空泵周围的杂物清除。

三、维护保养1. 定期检查油位a. 按照操作手册的要求，定期检查真空泵的油位。

b. 如发现油位过低，应及时添加或更换油。

2. 清洁真空泵a. 关闭真空泵的电源开关，确保真空泵停止运行。

b. 使用软布擦拭真空泵的外壳和零部件，确保清洁无尘。

3. 定期更换油a. 根据操作手册的要求，定期更换真空泵的工作油。

b. 在更换油时，确保使用合适的工具和设备，避免油液溅出或污染环境。

4. 检查密封件a. 定期检查真空泵的密封件，如发现磨损或老化，应及时更换。

5. 定期维护a. 根据操作手册的要求，定期进行真空泵的维护保养，包括清洗、润滑和紧固等。

四、安全注意事项1. 在操作真空泵时，应穿戴好个人防护装备，确保安全操作。

2. 避免将易燃、易爆或有毒气体引入真空泵，以免发生意外事故。

真空泵操作及维护指引真空泵是一种用于抽取气体或气体混合物的设备。

它被广泛应用于许多领域，如实验室研究、医疗设备、制药和化学工业等。

为了保持真空泵的正常运行和延长使用寿命，下面是一些真空泵操作和维护的指南。

操作指南：1.检查真空泵的工作原理和操作手册，了解设备的工作方式和使用限制。

2.在使用真空泵之前，确保设备连接正确，密封良好，并检查所有管道和接口是否松动或损坏。

3.打开泵的阀门，平稳地启动泵。

在启动过程中，应该保持泵的压力和流量在安全范围内。

4.避免过度工作、高负载或长时间运行，这样可以减少设备的磨损和损坏。

5.定期检查并清理真空泵的滤网和过滤器。

过滤器可能会被灰尘、杂质或污垢堵塞，影响泵的性能。

6.定期检查和更换润滑油。

润滑油在运行过程中会老化和污染，如果不及时更换，可能会影响泵的正常运行。

7.注重防腐蚀保护。

一些气体或气体混合物可能会对泵内部的金属部件产生腐蚀作用，导致设备损坏。

使用适当的防腐蚀涂层或材料可以延长设备的使用寿命。

8.使用维护记录和维护计划，定期进行维护和检修工作。

定期清洗、校准和更换磨损的零部件，以确保泵的正常运行。

维护指南：1.清理真空泵的外部表面，并确保排放出口通畅。

清除表面积聚的灰尘和污垢，以便散热和保持泵的性能。

2.检查泵的密封系统，确保没有泄漏。

定期更换密封件，以防止气体泄漏和设备损坏。

3.检查真空泵的电气连接和电线，确保电源线路正常并牢固连接。

4.定期检查真空泵的运行状态和性能。

使用适当的仪器进行测量和检验，以确保泵的工作参数在正常范围内。

5.定期校准泵的压力表和流量计，以确保其准确性和精度。

6.如果发现任何异常噪音、振动或异味，应立即停止使用真空泵，并检查设备是否出现故障或损坏。

7.定期进行泵的维护保养，包括清洗、润滑和更换磨损的零部件。

定期更换油封、轴承和密封件，以保持设备的正常运行。

总结：以上是真空泵操作和维护的一些建议和指南。

定期维护和保养真空泵是确保设备正常运行和延长使用寿命的关键。

液环式真空泵安全操作规程范本液环式真空泵是一种常见的真空设备，广泛应用于化工、医药、电子、冶金等领域。

为了确保操作人员的人身安全和设备的正常运行，以下是液环式真空泵的安全操作规程范本，共计____字。

请注意，该范本只作为参考，具体的操作规程应根据实际情况进行制定。

第一章总则第一条本规程适用于液环式真空泵的安全操作，涵盖设备的日常操作、维护和检修等内容。

第二条液环式真空泵的操作必须符合相关国家标准和规定，操作人员必须经过专门的培训，并持有相应的操作证书。

第三条操作人员必须了解液环式真空泵的工作原理、结构特点、安全操作规程和常见故障处理方法，并能正确操作设备。

第四条液环式真空泵的操作必须按照操作规程进行，并严格遵守安全生产规定，禁止违章操作。

第五条液环式真空泵的操作必须严格按照设备的使用说明书进行，特殊情况下必须按照专门的操作程序进行。

第二章操作规程第一节开机操作第六条开机前，操作人员必须检查液环式真空泵的工作环境，确保周围没有明火和易燃、易爆物品，确保通风良好。

第七条开机前，操作人员必须检查液环式真空泵的油位，并确保油位在正常范围内，没有泄漏。

第八条开机前，操作人员必须检查液环式真空泵的各个连接部位是否牢固，无松动和泄漏现象。

第九条开机前，操作人员必须检查液环式真空泵的电气设备是否正常，包括电源线、开关、保险等。

第十条开机时，操作人员必须站在安全位置，确保无人站在泵旁，然后将电源插头插入插座，按下启动按钮。

第十一条开机后，操作人员必须观察液环式真空泵的运行情况，确保无异音和异味，运行稳定。

第二节停机操作第十二条停机时，操作人员必须先关闭液环式真空泵的出口调节阀，将泵的负荷逐渐降低，然后将电源开关关闭。

第十三条停机后，操作人员必须观察液环式真空泵的停机情况，确保无滴水和泄漏现象。

第十四条停机后，操作人员必须清理液环式真空泵的工作环境，将周围杂物清除干净。

第三节日常维护第十五条每班交接班时，操作人员必须按照相关规定进行班前交接，交接班人员必须了解液环式真空泵的工作情况。

DEXLIQUID RING VACUUM PUMPS OPERATION AND MAINTENANCEMANUALINDEX1. INTRODUCTION Page32. REVIEW OF THE SHIPPING DOCUMENTS,,33. WARRANTY,,34. OPERATING PRINCIPLE,,45. TECHNICAL DESCRIPTION,,46. USE,,5USE AS A VACUUM PUMPUSE AS A COMPRESSOR7. OPERATING CONDITIONS,,6OPERATING DATAGAS AND VAPOURSSERVICE LIQUID SUPPLY8. TRANSPORT,,79. STORAGE,,8SHORT TERM STORAGELONG TERM STORAGE10. STANDARD NORMS FOR SAFETY,,8GENERAL PRESCRIPTIONSPRECAUTIONS DURING OPERATION11. ADDITIONAL RISKS,,912. INSTALLATION,,913. CONNECTIONS,,10PIPEWORKACCESSORIESELECTRICAL WIRING14. SERVICE LIQUID SUPPLY ARRANGEMENTS,,1015. START UP,,14PREPARATION TO START UPSTART UPSTOP16. SHUT DOWN PERIOD,,1517. MAINTENANCE,,1518. OPERATING PROBLEMS AND TROUBLE SHOOTING,,1619. REPAIR,,17DISASSEMBLY OF THE CASING, PORT PLATE AND IMPELLERREASSEMBLY OF THE IMPELLER, PORT PLATE AND CASING20. SPARE PARTS,,2121. PUMP SCRAP AND DISPOSAL,,21 ATTACHMENTS: SECTION WITH PART1. INTRODUCTIONThe purpose of the present manual is to ease the installation, the operation and the routine maintenance activities of the liquid ring vacuum pumps belonging to the DEX range.Before proceeding with the installation and the start up of the pump, it is very important to undertake the reading of the present manual, inform the operators and the plant personnel about the content of each section in order to grant the correct operation of the equipment as well as the maximum safety of the personnel in charge for installation, start up and maintenance.Please note that the DEX liquid ring vacuum pumps could be potentially harmful to people and things for the following reasons:-Rotating parts at high speed!-Deep vacuum-Fluids and gas handled by the equipment could be hazardous and toxic Array -Presence of electric powerThe non observance of the instructions reported in this manual or the improper use of the pump by unskilled and/or unauthorised personnel may result in severe damage to things or serious injury and even death of people!The Technical and Service Departments are available for any technical assistance or clarification you may need. In case of doubt, call up.2. REVIEW OF THE SHIPPING DOCUMENTSWhen receiving the goods, it is necessary to inspect and check them against the shipping documents. Make sure that no shipping damages are occurred to the equipment during transportation.3. WARRANTYThe warranty does not cover for damages or failures caused by mishandling, incorrect installation and wrongelectrical wiring of any piece of equipment of the plant.In any case the warranty excludes the reimbursement for any sort of damages originated by any cause.Ing. Centra declines any responsibility for what concerns to injuries of people and damages to things due tothe improper use of its equipment.For additional or replacement warranty clauses in respect to the statements of present manual, please refer to the contractual conditions mentioned in the order acknowledgement.Consumables are not subject to any warranty.4. OPERATING PRINCIPLE Pumps belonging to the DEX range are designed and operating based on the liquid ring principle.The pump consists of a cylindrical housing within which an impeller with fixed blades turns off set in respect to the housing itself.The impeller rotation spins by centrifugal force the service liquid around the housing thus forming a ring of liquid concentrically to the housing. Because of the off set between the housing and the impeller, during the impeller revolution, chambers between the blades are formed with a progressively increasing and decreasing volume resulting in producing respectively vacuum and compression. The presence of vacuum in the inlet port area draws in gas through the pump suction nozzle which is then compressed and discharged through the discharge port up to the dedicated pump nozzle.During pump operation, it has to be supplied a continuos service liquid flow in order to remove the heat absorbed by the liquid itself due to the isothermal compression.FIG. 1 5. TECHNICAL DESCRIPTIONThe DEX pump is single stage type, acting in parallel due to the symmetric design, with horizontal axis,provided with vary port valves. The rotating part is supported by two robust life grease lubricated ball bearings located in the casings at shaft ends.The pump is self standing on feet present under each casing.The pump shaft driving end has to be connected an electric motor in B3 construction through a flexible coupling.The shaft sealing is granted by two single mechanical seals, standardized according to DIN 24960, fitted directly on the shaft and located in each casing (shaft ends).The standardisation of specific items among different pump sizes reflects the modular design in order to rationalise the construction of the whole range and reduce the amount of spare parts to be kept on stock.SUCTION DISCHARGE SHAFTINLET PORTIMPELLER BLADESLIQUIDRING DISCHARGEPORT IMPELLER6. USEDEX pumps are mainly used for the following applications:Suction of gas and vapours from autoclaves and sterilizersVacuum packaging, drying and impregnationPrimingProcess under vacuum, suction of gas and vapours in the chemical, food and wine industryDryers and evaporators used in the textile, brick and soap industrySolvent recovery.• USE AS VACUUM PUMPThe whole range of DEX liquid ring vacuum pumps can handle any gas suitable with the material of construction and with the service liquid as well as limited quantity of liquid carry over flowing into the pump together with the process gas.The deepest suction pressure which can be achieved by the pump is related to the vapour tension of the service liquid; any time the vapour tension comes close to the suction pressure the pump may cavitate therefore it is advisable to keep the service liquid temperature as low as possible.Process conditions close to cavitation do require the installation of an anticavitation valve or relief valve to protect the pump (see section 13).In case it is requested a deeper suction pressure compared to what the pump can provide, it is possible to combine the pump with a gas ejector (or other type of equipment) in order to achieve even 10 mbar abs. of vacuum.The recommended operating limits are reported in TAB.1.The extensive use of the pump under cavitation conditions may result in heavy damages to the pump itself.• USE AS COMPRESSORThe DEX liquid ring pump range can be used also as a compressor.Normally when the gas suction pressure is atmospheric (1013 mbar abs.), the discharge pressure must not exceed the differential pressure stated in TAB.1 where are indicated the operating limits.TAB. 1PUMP MODELDEX 600-800Max. pump speedrpm 1750Max. inlet gas temperature° C 100Max. service liquid temperature° C 75Max. discharge pressure (vacuum pump)mbar 500Max. differential pressure (compressor)mbar11007. OPERATING CONDITIONS•OPERATING DATAThe nominal pump capacity and the absorbed power related to the suction pressure or differential pressure can be determined by reading the performance curve attached to the technical-commercial documentationsubmitted with the offer or with the order acknowledgement; in any case it will be provided copy of upon customer request.•GAS AND VAPOURSGases and vapours handled by the pump as well as the service liquid must not contain solid particles which may damage the seal surface of the mechanical seal stationary and rotating ring; minor quantities of fine solids in suspension are admitted.In case the inlet temperature of the process gas is above 70°C, it may be necessary to increase the service liquid flow rate up to even 50% more compared to the design flow stated in TAB. 3.If the inlet stream contains a consistent quantity of condensables, it is advisable to install a pre condenser ahead of the pump suction nozzle; the condensate resulting from the cooling can flow into the pump provided that the total amount shall not exceed the allowed max. quantity of liquid carry over stated in TAB 2.•SERVICE LIQUID SUPPLYAs already mentioned above, the service liquid shall not contain any solid particles therefore it is recommendable to install a strainer in the service liquid supply piping.The flow rates stated in TAB. 3 are mandatory; those values are referred to suction conditions of dry gas only.The pressure of the service liquid supply shall be adequate to overcome the pressure losses of the liquid through the piping and through the heat exchanger, if any, plus assure a positive pressure of 0,5 bar above the pump discharge pressure at pump service liquid inlet.The selected service liquid must be compatible with the process gases and vapours, its density shall range from 800 to 1200 Kg/m3 and its viscosity shall be below 8 cST.Pump improper use or not in accordance with what specified and recommended in the !present manual may result in malfunctioning of the equipment and in seriousconsequences for people and things.TAB. 2Max. quantity of liquid carry over allowedPUMP MODELthrough the suction nozzle (m3/h)Continuos operation Discontinuous operationDEX 6006,26,7DEX 8007,88,4TAB. 3DESIGN SERVICE LIQUID FLOW RATE (m3/h)VACUUM PUMP COMPRESSORPUMP MODEL RPMSuction pressure (mbar)Differential pressure (mbar)402006002006001000145021,91,81,81,71,6 DEX 60017502,22,2221,91,814502,52,252,12,22,12DEX 80017502,52,252,12,22,128. TRANSPORTBefore arranging the transport of the pump, the following has to be checked:-Weight of the pump/equipment-Overall dimensions of the pump/equipment - Lifting points The pump must be transported by selecting adequate means of lifting and transportation suitable to the pump weight and to its packing dimensions nevertheless in compliance with the safety standards on force.When transporting, installing and performing maintenance, it is important to grant a safe lifting of the equipment; use serviceable lifting slings installed and operated by skilful personnel (see FIG. 2).Any eye bolt or lifting point present on a single part of the pump shall not be used for any reason to lift the whole pump assembly or the vacuum unit.FIG. 2!9. STORAGEAll DEX pumps are dispatched with the main connections like suction and discharge nozzles, service liquid connection, etc. closed by plastic plugs or adhesive disks.•SHORT TERM STORAGE (UP TO 2 MONTHS) :-Store the pump indoor and possibly in a dry and clean environment.-Make sure that the ambient temperature does not go below 5°C.-On a routine basis (every 10 day max.) turn the pump rotating part for some revolutions by acting on the motor cooling fan.•LONG TERM STORAGE (MORE THAN 2÷3 MONTHS) :-Lift the pump from the floor by putting wood blocks underneath.-Periodically replace the inhibitor oil to increase the internal preservation status or pour in additional oil (example Mobil Oil type SINTILO R) through the suction nozzle after having removed the protection plugs. Afterwards it is recommendable to re install the plugs.-Fully cover the pump with a plastic sheet or PVC film and put inside anticondensation products.-Check on a regular basis the conditions of the protections.-On a routine basis (every 30 day max.) turn the pump rotating part for some revolutions by acting on the shaft drive end or on the coupling if it is already installed on a base and connected to a motor.10. GENERAL NORMS FOR SAFETYBefore pump start up it is necessary to activate all protection devices meant for people and things so that any possibility of hazardous risk is avoided during operation but also during routine maintenance of the pump and of its accessories.•GENERAL PRECAUTIONSDEX pumps shall be used exclusively for the specified duty and within the limitations statedin the technical-commercial documentation submitted at quotation stage or with the orderacknowledgement.For any use not covered by the present manual, it is necessary to contact the TechnicalDepartment in order to get confirmation of the suitability to the new operating conditions interms of performance, safety and duration.•PRECAUTIONS TO BE FOLLOWED DURING OPERATION-Avoid to get close to pump suction and discharge nozzles.-In case the pump is running at high temperature due to hot sucked gas or hot service liquid,protections against the accidental contact with external parts have to be foreseen andinstalled.-When running, do not disconnect any pump auxiliary piping (service liquid supply line, etc.).-Avoid to run the pump under cavitation for long time (it makes high and unpleasant noise).-On routine basis, the efficiency of the monitoring and protecting devices has to be checked.-Check that all electrical devices with protection duties are installed and activated.!!11. RESIDUAL RISKSAvoid to have the pump suffering from:-Shocks.-Mishandling or moving errors of mobile means present around the pump.-Hitting with sharp and heavy equipment.-Dry operation or running under cavitation.-Improper use with dangerous or hazardous liquids and gases, different from thosestated in the specifications issued for order.In case of failure, check that all protection and safety devices are functioning and activated,afterwards disconnect the electric power supply and advise the plant personnel responsible for the operation.12. INSTALLATIONDEX pumps are normally connected to the electric motor by means of a flexible coupling.The equipment is accommodated on a base in welded construction.It is mandatory to fix the pump base on a foundation made in concrete by using anchor bolts or expansion bolts passing through the dedicated base holes.The base shall be located on a levelled floor; if required, use metal shims of different thickness to put underneath the base in order to get a proper base levelling.When the pump is supplied together with the motor on a base, the alignment of the assembly is made in the workshop; in any case it is necessary to re-check the alignment of the assembly after the fixing on the foundation.If it is a new installation, before tightening the foundation bolts, check the concrete set and its consistency.• PUMP-MOTOR ALIGNMENTBefore starting up the pump it is mandatory to check the pump-motor alignment.To check the alignment it is necessary to inspect the concentricity and parallelism of theinstalled coupling halves by using a ruler, a feeler gauge, a sliding gauge or a dial gauge.Remove the coupling guard first; put the ruler against the halves in position 1-2-3-4 (see Fig. 3) and check with the feeler gauge or the dial gauge that the radial clearance “a ” does not exceed 0,1 mm.Measure with the sliding gauge the distance “b ” in position 1-2-3-4; the difference among the four measurements shall not exceed 0,1mm.Additionally, check that the distance between the coupling halves “b ” is not less than 2 mm.WHEN THE ALIGNMENT CHECK HAS BEEN COMPLETED, RE-INSTALL THECOUPLING GUARD!FIG. 3!!!13. CONNECTIONS•PIPEWORKAs already stated previously, the pumps are dispatched with the main nozzle and the service liquid connection closed with protection plugs.Remove the protections only when the pump is ready for being connected to the plant pipework. Before doing it, make sure that all piping has been checked for cleanness.To increase the protection at start up, during the first operation hours it can be fitted an inlet screen on the pump suction with the aim to avoid that any welding shot or dirt still present in the pipework may enter into the pump.The suction and discharge nozzles can be easily identified by checking the arrows located closed to each nozzle.Each pipe connected to the pump must have the same diameter size of the respective pump nozzle and shall be constructed so that it easily connects with the dedicated pump nozzle allowing the tightening of the bolting without any consequence to the pump casing.The service liquid supply pipe, before branching off to the service liquid connection points located on each pump casing, shall be double in size compared to each pump connection point.It is extremely important to adequately support the suction and discharge pipework in order to avoid loads on the nozzles which may generate problems to the smooth operation of the pump.When constructing the pipework, pay attention to the fittings and to the supporting structures in order to take into account allowance for thermal expansion.The vertical section of the discharge line shall not exceed 1 meter height in order to avoid the forming of backpressure inside the pump with consequent motor overload and pump flooding during pump shut down caused by the return of the discharged liquid back into the housing.14. SERVICE LIQUID SUPPLY ARRANGEMENTS•ONCE THROUGH (FIG. 4)Standard arrangement for installation where there is enough fresh service liquid available and there are no handling problems down-stream as both the liquid and the gas are not considered polluted and polluting.The gas mixed together with the service liquid can be sent directly into the discharge system or, if it is requested a gas-liquid separation, to a separator tank: by gravity, the gas will flow out from the top and the liquid from the bottom.It is recommended to make sure that the service liquid supply pressure will be 0,5 bar above the pump discharge pressure.•PARTIAL RECIRCULATION (FIG. 5)This configuration is particularly indicated when the fresh liquid consumption must be low, the pump can take service liquid at a higher temperature compared to the fresh liquid and when there are no handling problems down-stream as both the liquid and the gas are not considered polluted and polluting.The service liquid flow consists partly of fresh liquid (normally approx. 50%) and the remaining quantity by liquid at higher temperature recovered from the separator tank.Also in this case it is recommended to make sure that the service liquid supply pressure will be 0,5 bar above the pump discharge pressure.•RECIRCULATED SERVICE LIQUID ARRANGEMENT (FIG. 6)This arrangement has to be followed any time there is an application which requires to avoid any process gas leakage or when there are involved fluids which for their chemical composition or pollution caused by the process gas can not be leave the plant for environmental or process reasons.The service liquid flows from the pump into the separator tank, recirculated back through a heat exchanger where it is cooled down at the specified temperature and then back to the pump.In case the heat exchanger generates a high a pressure drop thus altering the conditions for a good service liquid supply, it is necessary to install a recirculation pump to restore the pressure required in the system.•ACCESSORIES (see FIG. 4-5-6-7)Particular attention has to be paid when installing the gaskets between flanges which shall be placed concentrically in respect to the flange to avoid the restriction of the area dedicated to the passing of fluids.-A check valve is fitted on the pump suction nozzle when it runs as a vacuum pump in order to avoid the loss of vacuum ahead of the pump; the check valve is installed on the gas discharge line when the pump runs as a compressor in order to prevent the loss of the backpressure.-The separation of the process gases from the service liquid normally takes place in a separator tank which has also the duty to recover the service liquid completely or partially.The separator can be fitted directly on top of the pump discharge nozzle or to the side of the pump with a tangential inlet.Normally the separator tank is provided with an overflow connection (to drain the excess of liquid in case the pump sucks liquid or process vapours which do condense) and a service liquid make up connection.-When the DEX pump runs with full recirculated service liquid, it is required to cool down the service liquid at the design inlet temperature; this can be achieved by using a heat exchanger located on the recirculated service liquid line back to the pump.-The service liquid recirculation pump is usually installed together with a check valve fitted on its discharge line and followed down stream by a flow adjusting valve.-The monitoring of the service liquid flow can be made either with a pressure gauge, located down stream the recirculation pump, in combination with the knowledge of the recirculation pump performance or, more accurately, by a flow meter or a flow indicator installed on the service liquid recirculation line.-When the pump runs close to cavitation conditions, or the process stream contains gases with high vapour tension, it is recommend to install an anticavitation valve on the service liquid supply line before it branches off to the casing connection points; It shall be fitted in vertical position (!) and normally connected to the separator.-To avoid the flooding of the liquid ring pump during shut down time, it is required to stop the recirculation pump at the same time when the liquid ring pump is stopped.-On complex plants or when there are present toxic and hazardous gases and liquids, normally there are installed monitoring, control and self adjusting equipment, safety devices to check levels, flow rates, pressures in all critical points like low/high level switches, actuated valves, control valves, safety valves and any sort of extra safeties/alarms.-When installing a gas ejector on the pump suction, it can be achieved a deeper vacuum.The ejector does not have any impact on the absorbed power and usually it is installed in vertical position.(it can be also installed in horizontal position without affecting the functioning).The gas ejector motive fluid must not contain any liquid droplets!To reduce the hogging time when the pump is combined with a gas ejector, it is recommendable to provide an ejector by-pass line including shut off valve; as soon as the pump runs close to 50 mbar abs, the ejector can be brought in operation by closing the by pass valve.LEGENDNOZZLE ACCESSORIESP 1Vacuum pumpA SUCTIONM 1 Vacuum pump electric motorV 1 Separator tankB DISCHARGEE 1 Heat exchangerP 2 Recirculation pumpC SERVICE LIQUID MAKE UPM 2 Recirculation pump electric motorCV 1 Inlet check valveD COOLING WATER INLETPI 1 Vacuum gaugeTI 1 Temperature gaugeE COOLING WATER OUTLETVRV 1 Anticavitation valveJ 1 Gas ejectorF OVERFLOWVB 1 Drain valveVB 2 – VB 5 Shut off valveG SEPARATOR DRAINVB 3 – VB 4 Adjusting valveH SERVICE LIQUID INLET•WIRINGThe electrical wiring must be carried out by specialised personnel only; it has to be strictlyfollowed the instructions provided by the electric motor supplier and by the variousmanufacturers of the electric components involved in.Check that the motor name plate data matches with the local power supply in terms ofvoltage, frequency, phase and absorbed current.In case of three phase power supply, check that the voltage of all phases is identical.Connect the motor earthing properly.Remove the terminal box cover by losing the fixing screws; connect the wires as indicated inthe instructions or on the inside of the cover and then reposition the terminal box coverand fix it by tightening the dedicated screws.It is recommended to install a thermal circuit breaker in order to protect the motor fromexcessive low voltage or overload.For its correct sizing, follow the current values reported on the motor nameplate.!15. START UP•PREPARATION TO START UPWhen the pump is started up for the first time, the following checks shall be performed:-Open the shut off valve located on the pump discharge line, if any.-Check the tightness of the gaskets installed in the pipework.-Prime the pump and the service liquid lines up to the pump center-line or up to the highest level allowed by the level control devices.-Check the sense of rotation of the liquid ring pump and of the recirculation pump, if any, by starting the dedicated motors for a very short time. If the sense of rotation is not correct, assuming the power supply is three phase, disconnect the power supply, open the motor terminal box and exchange the connection of two phases, afterwards close the terminal box by fixing the cover; when performing this step make sure that the safety device which prevents the accidental supply of power is activated.•START UPStart up the pump after having checked that all shut off valves located in the suction and discharge lines are open as well as the service liquid supply shut off valve in case of once through or partial recirculation arrangement. Start up the recirculation pump, if any.Just after start up, the service liquid flow adjusting valve has to be set according to the amount required by the pump. Block the achieved valve setting; this position shall be kept even during shut down period (for safety, it is advisable to remove the hand wheel to prevent any tampering).The exact service liquid flow required by each DEX model is specified in TAB. 3.Open the cooling water supply to the heat exchanger, if present, and adjust the flow according to the value stated in the specific documentation.Check that the current absorbed by the motor and indicated by the Amp meter located in the panel does not exceed the value reported on the motor nameplate.Check that the pump runs smoothly by turning silent and without vibration.In case during pump operation there is the impression that there is something wrong with the pump, it is required to stop it immediately and to identify the reason of the malfunctioning.During the normal operation, check on a routine basis the main parameters like the suction pressure, the discharge pressure by reading the vacuum or pressure gauge, the level in the separator, the service liquid flow and temperature and the motor absorbed current.If required, add make up liquid inside the separator.DO NOT RUN THE PUMP WITHOUT SERVICE LIQUID !BEFORE STARTING UP THE PUMP, IT IS NECESSARY THAT THE PLANT IS !COMPLETED FROM BOTH MECHANICAL AND ELECTRICAL POINT OF VIEW, INACCORDANCE WITH THE LOCAL SAFETY STANDARDS ON FORCE.•STOPSwitch off the vacuum pump motor and the recirculation pump motor, if any; stop the service liquid supply in case of once through or partial recirculation or stop the cooling water supply to the heat exchanger by closing the dedicated valves in case of recirculated service liquid arrangement.If the process conditions require the pump stop against the presence of vacuum ahead of the pump below 100 mbar, in order to allow the pump to start again, it is necessary to arrange the equalising of the pressure inside the suction and discharge lines.This is not required if there is installed the anticavitation valve.16. SHUT DOWN PERIODWhen it is foreseen a relatively long shut down period (more than 2 months), or when meant required,it is necessary to drain the liquid ring pump but also the recirculation pump and the heat exchanger, if present.Remove the threaded drain plugs located in the lowest part of the pump casing and wait for the complete discharge of the liquid.This procedure has to followed also when it is required to preserve the pumps and the heat exchanger from potential damages caused by freezing or when the service liquid may generate deposits.If the service liquid is classified hazardous then before draining the pump it ismandatory to flush the service liquid circuit by using a suitable liquid; the flushingcan be made by keeping the pump in operation.IT IS END USER DUTY TO MAKE SURE THAT THE DISPOSAL OF THE SERVICELIQUID MAY CAUSE DANGER TO PEOPLE HEALTH AND TO THINGS AND THAT THEADOPTED DISPOSAL PROCEDURES SHALL COMPLY TO THE LOCAL LAW ANDRELEVANT STANDARDS ON FORCE.17. MAINTENANCEIf the pump runs within the limits of the operating range specified in the previous sections and, more important, if the service liquid is clean and does not contain solid abrasive particles, the DEX pumps will be able to operate for long time without the need of performing any maintenance activity.The personnel in charge for the plant operation is routinely requested to check the smooth operation of the pump according to the procedures reported in section 15.Extreme care has to be dedicated any time there is a leak from the mechanical seals orwhen an unusual noise or vibration arises either from the pump or from the motor particularlyif it is associated with an increase in power consumption or irregular fluctuations of the Ampmeter.When water is used as service liquid, especially in case of reciculated service liquidarrangement, it is required to check its hardness as it might form lime deposits on theinternals with consequent wear of the inner parts and increase of the absorbed power.The most important and frequent maintenance activities are normally the following:•Replacement of the mechanical seals •Pump internal cleaning • Replacement of the bearingsFor any activity involving the pump disassembly and reassembly in order to replace failed parts, please refer to Section 19 – REPAIR.!!。