机械密封培训课件(ppt 82页).ppt

1、西部管道密封培训,JohnCrane Tech(Tianjin) Co.,Ltd,培训内容概述,密封基础知识 密封系统知识 密封的安装要求 密封的失效大致判断 与客户技术人员进行交流,机械密封基础 第一部分,Concepts of Mechanical Seals机械密封概念,Shaft,Process Fluid 密封流体,Leakage 泄漏,Environment 环境,Vessel Wall 釜壁,The Basic Sealing Problem:Preventing Leakage基本的密封问题: 防止泄漏,Shaft,Process Fluid 流体流动,Leakage 泄漏,E

2、nvironment 环境,Vessel Wall 釜壁,The Concept of anEnd Face Mechanical Seal机械密封端面的概念,Shaft Movement 轴的运动,Required Features必须的特征,Small axial clearance小的轴向间隙 Self adjusting自调节,Mating Ring 配合环,Primary Ring 补偿环,Secondary Sealing Element 辅助密封,A Flexible Seal Flexible 机械密封,Hydrostatic loading流体静力学负荷 Secondary

3、sealing elements辅助密封 Replaceable parts可替换的部件,O-Ring O型圈,Shaft轴,Mating Ring 配合环,Primary Ring补偿环,Snap Ring卡环,Anti-X Ring 挡环,O-Ring O型圈,Disk推环,Springs弹簧,Retainer传动套,Set Screw定位螺丝,An Example of a Complete Seal,Simply put, a mechanical seal is:简单的说,机械密封就是,1.A wearable, stationary, primary sealing element

4、 一个耐磨,静止的密封件 2. A wearable, rotating, primary sealing element 一个耐磨,旋转的密封件 3. A secondary sealing element 二次密封 4. A mechanical loading device to press primary sealing elements 1 and 2 against one another, and 使件1和件2相互贴合的机械装置 5. Auxiliary components to complete seal 辅助密封,Non-flashing 没有闪蒸,Flashing 闪蒸,

5、Parallel 平行,Converging 收敛,Diverging 发散,Face Separation 密封面分离,Shape: 形态,Gap: 间隙,Fluid: 流体,The Sealing Interface密封接触面,Lubricant润滑剂,Separation分离面,Magnified Surface A 放大面,Magnified Surface B放大面,Heat热量,The Sealing Interface密封面,Lubrication Purpose:润滑目的 Separate surfaces分离两个面 Prevent contact of high surfac

6、e points 防止出现面接触 Reduce friction/heat generation减少摩擦/生热,Process Fluid Acts as Lubricant Between Faces流体在两个面之间充当润滑剂的过程,Gland密封端盖,Pump Housing 泵腔,Process Fluid 工艺流体,Invisible Leakage: 不可见泄漏 Fluid Evaporates Upon Reaching Atmosphere 微量的泄漏在大气侧蒸发,Primary Ring 补偿环,Mating Ring 配合环,Gland密封端盖,Pump Housing 泵腔

7、,No Fluid Or Dry Running 没有流体或者干运转,Primary Ring 补偿环,Mating Ring 配合环,Without Lubrication, Faces Run Dry And Overheat 没有润滑干运转导致过热,Mating Ring 配合环,Primary Ring补偿环,Heat Generation 生热,Rubbing摩擦 Viscous Shear粘性剪切力,Heat Transfer热传递,Conduction传导 Convection对流,Injection注入,Flushing冷冲洗,Removes Heat带走热量 Replenis

8、hes Cool Clean Lubricating Liquid 补充润滑液,Primary Seal: Flush基本密封:冲洗,Single Seal Flushing By - Pass from Discharge (API Plan 11) 单密封通过出口进行冲洗,By- pass Line from Pump Discharge to Seal Gland 从泵出口到密封端盖的管线,Discharge出口,Flow流动,Suction 入口,Primary Seal: Flush基本密封:冲洗,Minimum Pressure .3 bar / 5 psi Above A? 最小

9、压力值要大于A处0.3Bar,Flow 流动,Discharge出口,Suction 入口,Restrictional Device (Bushing) 限流装置,Single Seal Flushing from External Source (API Plan 32) 单密封通过外部来源进行冲洗,A,Primary Seal: Quench 基本密封:急冷,Restrictional Device (Packing) 限流装置(盘根,Quench Source急冷源,Process Fluid工艺流体,Single Seal Quench from External Source (AP

10、I Plan 62) 单密封通过外部急冷,API Piping Plans API 冲洗方案 第二部分,JOHNCRANE,API Piping Plans API 冲洗方案,Integral (internal) recirculation from pump discharge to seal 内部循环从泵的出口到密封,Advantage 优点 - No external piping 没有外部冲洗 Limitations 局限性 - Changing flow rate required dismantling of pump 改变流量需要拆泵 - For clean pumpages

11、only 只能是适用干净的介质,API Piping Plans API 冲洗方案,Points to Note for API Plan 02: API 02 冲洗方案应注意的事项： The injection tapping is used for venting prior to startup. -在开车前，入口用来进行放空 API plan 02 is often used together with plan 62, especially on high temperature bellows seals.冲洗方案2经常与62一起用，特别是用在高温波纹管密封,API Piping

12、Plans API 冲洗方案,No flushing to the mechanical seal (dead-ended) 机械密封里没有冲洗,Points to Note for API Plan 11: API 冲洗方案11 应注意的事项 - Use an orifice to restrict the flow rate if the discharge pressure is 3 bar higher than seal chamber pressure.如果出口压力高于密封腔压力3bar，需要用一个孔限制流量 - Use on clean and low abrasives dut

13、ies用在干净，含磨石性颗粒少的工矿,API Piping Plans API 冲洗方案,Seal Flushing By-Pass from Discharge 单密封通过出口进行冲洗,Recirculation from seal chamber through a flow control orifice and back to pump suction从密封腔里出通过一个孔板返回到泵的入口,Points to Note for API Plan 13: API 冲洗方案 13 应注意的事项 - Use an orifice to restrict the flow rate if th

14、e seal chamber pressure is 3 bar higher than suction pressure.如果密封腔压力高于入口压力3bar，需要用一个孔板限制流量 - handle abrasives duty better than API plan 11处理含有磨石性颗粒的工矿13方案号优于11方案 - higher seal chamber pressure to suppress vaporisation较高的密封腔压力可抑制它的汽化,API Piping Plans API 冲洗方案,Points to Note for API Plan 14: API 冲洗方案

15、 14 应注意的事项： - Flow back to suction side will evacuate vapours that may collect in seal chamber. - Recommended for light hydrocarbon service,API Piping Plans API 冲洗方案,Recirculation from pump discharge through a flow control orifice and cooler to seal Open Loop Cooling Circuit,Cooling Water Outlet冷水出口

16、,Cooling Water Inlet冷水入口,API Piping Plans API 冲洗方案,Recirculation from a pumping ring in the seal chamber through cooler and back to seal Closed Loop Cooling Circuit 冲洗液通过密封腔中的泵效环从密封腔中流出经过换热器，再返回到密封中，形成自封闭循环。形成封闭的冷却回路,Throat bushing,Suction入口,Discharge出口,18 - 24,Vent at highest point of the piping排气在

17、管线的最高点,Cooling Water Outlet冷水出口,Cooling Water Inlet冷水入口,mechanical seal with pumping ring,Heat exchanger换热器,API Piping Plans API 冲洗方案,Points to note for API Plan 23: Thermosyphon design热虹吸设计 * heat exchanger 换热器 18 to 24“ above pump centre line. 在泵中心线以上 18 to 24 * Prevent overheating in standby and

18、startup. * 在泵启动和备用时，要防止过热。 Install close fitting neck bushing at the bottom of seal chamber to isolate the heat from the impeller end.在密封腔底部安装喉部衬套用来隔离从叶轮传出的热量 Used on high temperature applications to minimise heat load on the cooler by cooling only small amount of liquid that is recirculated.用于高温工况，

19、通过冷却密封腔的小部分的循环流体来使冷却器的热负荷降至最低. For high temperature boiler feed pump applications用于高温锅炉给水泵上 Other applications其他应用 * high temperature liquid close to bubble point. * 接近沸点的高温液体,API Piping Plans API 冲洗方案,Recirculation from pump discharge through a cyclone separator delivering clean fluid to the seal a

20、nd fluid with solids back to pump suction line冲洗液从泵出口流出，通过一旋液分离器，使干净流体进入 密封腔，带有颗粒的流体返回到泵入口处形成封闭循环,API Piping Plans API 冲洗方案,Points to Note for API Plan 32:对于API plan 32 须注意: - Chose a proper source of seal flush to eliminate the potential for vaporisation of the injected fluid and to avoid contamina

21、tion of the fluid being pumped with the injected flush.选择合适的密封冲洗源， 以减少冲洗流体的汽化，同时可避免冲洗流体被污染。 - Install a labyrinth bushing at the bottom of the stuffing box to control the flushing and pressure if necessary. - - 如有必要的话，在密封腔底部安装喉部衬套或迷宫密封来控制冲洗和压力,API Piping Plans API 冲洗方案,Single Seal Flushing from Exte

22、rnal Source 单密封通过外部来源进行冲洗,Throat Bushing,Recirculation from pump discharge through a cyclone separator delivering clean fluid through a cooler and then to seal and fluid with solids back to pump suction line,Cooling Water Outlet,Cooling Water Inlet,API Piping Plans API 冲洗方案,Needle valve,External res

23、ervoir providing a dead-ended blanket of fluid to the quench connection of the gland,Points to Note for API Plan 51:对于API plan 51 须注意: - Dead ended blanket on atmospheric side of seal to prevent freezing of moisture. Seal face will not stick together when the pump started. - 在密封大气侧，一端封闭的 情况可防止潮气的冻结，

24、这样 在泵启动时，密封面就不会 粘接在一起。 Typical application : 典型的应用 Pump operating below 0 C应用于泵在 0C以下 - API 610 8th Edition has eliminated this piping plan.API 610 第八版已经取消这个冲洗方案,API Piping Plans API 冲洗方案,Piping Systems,API Piping Plans API 冲洗方案,A fluid used as a lubricant or buffer between dual mechanical seals. 这种

25、液体象缓冲剂，润滑剂用在双机械密封 The buffer fluid is always at a pressure lower than the pump process pressure being sealed.缓冲液的压力通常低于被密封的介质的压力,A fluid which is introduced between dual mechanical seals to completely isolate the pump process liquid from the environment.双机械密封里的隔离液用于是泵的工艺液体与大气分离 Pressure of the barri

26、er fluid is always higher than the pump process pressure being sealed.隔离液压力总是高于泵的运作压力,The purpose of fluid circulationis to remove heat from mechanical seal,API Piping Plans API 冲洗方案,On applications below ambient temperature, circulation of barrier fluid may not be desirable. 这种情况适用于比室温低的工况，隔离液的循环不能

27、满足要求。 The atmosphere will heat the reservoir and consequently add heat to the seal area.外部对储罐进行加热，从而，对密封区域进行加热,Fluid circulation by temperature difference between the seal and reservoir. 流体依靠密封腔和储罐的温差进行循环 Higher temperature liquid at seal has lower density rises to the reservoir.密封中的高温流体密度较小，依靠热虹吸现象

28、上升到储罐中 Lower temperature liquid at reservoir has higher density falls to the seal to provide cooling.储罐中的低温流体密度较大，下降到密封腔中对密封进行冷却,External Force Circulation,Thermosyphon,Pumping Ring,Dead Ended,API Piping Plans API 冲洗方案,Points to Note for API Plan 52: Typically used with an Arrangement 2 unpressurise

29、d dual seal.通常用于不带压双封 During normal operation, circulation is maintained by an internal pumping ring.在正常操作情况下，通过腔内的泵效环维持循环 The reservoir is usually continuously vented to a vapour recovery system and is maintained at a pressure less than the pressure in the seal chamber.储罐通常与回收系统相连通，罐内压力通常低于密封腔压力,Pr

30、essure Gauge 压力计,Level Gauge 水准仪,Fill valve,Orifice,Drain,Level Switch (H) 电平开关,Level Switch (L,Pressure Switch 压力开关,Normally Open,Vent valve 排气阀,External reservoir providing buffer fluid for the outer seal of an unpressurised dual seal arrangement. 外部储罐对不带压双封的外密封起缓冲液的作用,API Piping Plans API 冲洗方案,Pr

31、essure Gauge 压力表,Level Gauge 水准仪,Level Switch (L) 电平开关,Vent Valve 排气阀(Normally Close) 通常关着,Orifice,Pressure Switch 压力操纵开关,External Pressure 外部压力 Source,One-way Block Valve(Normally Open,Points to Note for API Plan 53: Typically used with an Arrangement 3 pressurised dual seal.通常用于带压双封 During normal

32、operation, circulation is maintained by an internal pumping ring.在正常操作情况下，通过腔内的泵效环维持循环 The reservoir pressure is greater than the process pressure being sealed.罐内压力通常高于被密封介质压力,External reservoir providing pressurised barrier fluid for the outer seal of an pressurised dual seal arrangement.外部储罐对带压双封的

33、 外密封起隔离液的效果,Drain,API Piping Plans API 冲洗方案,Points to Note for API Plan 54: Typically used with an Arrangement 3 pressurised dual seal.通常用于带压双封 During normal operation, circulation is maintained by an external pump or pressure system.在正常操作情况下，通过外部的泵或压力系统维持循环 The circulating barrier fluid pressure is

34、 greater than the process pressure being sealed. 循环隔离液的压力高于被密封介质的压力,External barrier fluid system providing pressurised barrier fluid for the outer seal of an pressurised dual seal arrangement 外部隔离液系统对带压双封的外密封提供带压隔离液,API Piping Plans API 冲洗方案,Safe to use, handle, store储藏、操作、使用安全可靠 Stable liquid at a

35、mbient temperatures在室温下，性能稳定 Not a VOC, VHAP or other regulated compound 不易挥发、非有毒物质 Non flammable不易燃烧 Non foaming when pressurised高于常压时，不易起泡 Clean and good lubricity干净且有较好的润滑性 Compatible with process fluid与工艺流体有互容性 Compatible with seal materials与密封材料相一致 Good heat transfer properties有好的传热性能 Good flow

36、 qualities at very low temperatures 在低温下，有好的流动性 Low solubility of gas对气体有较低的溶解性 Local availability当地容易获得 Low cost成本低,VOC : Volatile Organic Compound VHAP : Volatile Hazardous Air Polutants,Selection of Buffer / Barrier Fluid,API Piping Plans API 冲洗方案,Tapped connections for the purchasers use 在接口处攻螺纹

37、，以方便用户使用,Point to Note for API Plan 61:对于API plan 61 须注意: Typically this plan is used when the purchaser is to provide fluid (such as steam, gas, or water ) to an auxiliary sealing device. 通常在买方能给密封辅助系统提供流体（如蒸汽、气体或水）的情况下，才采用该方案,API Piping Plans API 冲洗方案,Points to Note for API Plan 62: 对于API plan 62

38、须注意: The quench may be required to prevent solids from accumulating on the atmospheric side of the seal.增加吹扫口以防止在密封大气侧有颗粒的积累 Typically used with a close-clearance throttle bushing. 普遍使用节流衬套,API Piping Plans API 冲洗方案,Single Seal Quench from External Source 单密封通过外部急冷,API 682 2nd Edition API 682 第二版New

39、 Piping Plans 新的冲洗方案,Plan 14 (Plan 11+13) 冲洗方案14 Plan 53s - Arrangement 3, Contacting Wet (CW) Seals 53 方案-排列方案3，接触式湿密封 53a traditional configuration 传统构造 53b bladder accumulator 蓄能器 53c piston pot/ accumulator 活塞/蓄能器 Containment Seal 二次辅助密封 Plan 72 Arrangement 2 w/ Containment Seal (CS) Plan 75 Arr

40、angement 2 w/ Containment Seal (CS) Plan 76 Arrangement 2 w/ Containment Seal (CS) Gas Barrier Seals 气体 Plan 74 Arrangement 3, Non-Contacting (NC) Seals排列方式3，非接触式密封,Plan 53a (A.4.12,Arrangement 3, Contacting Wet (CW) Seals排列方式3，接触式湿密封 Dual Pressurised (Double) Seals 带压双封 Utilises direct nitrogen bla

41、nket for pressure利用氮气层来增压 due to nitrogen entrainment in the barrier liquid API 682 limits the maximum nitrogen pressure to 10 barg, JC recommendation is maximum nitrogen pressure 21 barg, as long as the barrier fluid temperature is less than 120C API 682 限制了氮气的最大压力为10barg, 约翰克兰建议只要隔离液温度小于120度， 最大氮气

42、压力21barg,API 682 2nd Edition API 682 第二版 New Piping Plans 新的冲洗方案,Plan 53b (A.4.12,Arrangement 3, Contacting Wet (CW) Seals 排列方式3，接触式湿密封 Dual Pressurised (Double) Seals 带压双封 Utilizes bladder accumulator for pressure 利用蓄能器来增压 Bladder eliminates nitrogen contact with barrier liquid蓄能器把氮气与隔离液分开 Allows f

43、or higher pressure applications 允许高压力应用,Configuration Includes: Accumulator 蓄电池 Pressure Indicator 压力显示器 Pressure Switch压力开关 Heat Exchanger换热器,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,Plan 53c (A.4.12,Arrangement 3, Contacting Wet (CW) Seals排列方式3，接触式湿密封 Dual Pressurised (Double) Seals

44、带压双封 Utilizes piston pot for pressure 利用活塞增压,API 682 2nd Edition API 682 第二版 New Piping Plans 新的冲洗方案,Plan 53c (A.4.12,Allows for higher pressure applications 允许高压力应用 Configuration includes:构造包括 Piston pot 活塞 Pressure indicator压力显示器 Pressure switch 压力开关 Heat exchanger换热器 Level switch电平开关,Piston pot e

45、liminates nitrogen contact with barrier liquid活塞缸阻断了隔离液与氮气的连接 Piston provides constant pressure ratio to seals (1.1:1) 活塞给密封提供持续的压力比率,Spring 弹簧,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,Barrier Fluid Temperature (7.3.4.1.1)隔离流体温度,Liquid barrier systems shall be designed such that that m

46、aximum temperature differential between the barrier fluid inlet and outlet immediately adjacent to the seal chamber is: 设计隔离液系统允许的温差不一样，入口和出口温差不一样 8 degree C for glycol /water or diesel barrier fluids; and 对于水，乙二醇，柴油隔离液，允许最大温差8度 16 degree C for mineral oil barrier fluid 矿物油隔离液 允许最大温差16度,Plan 11 with

47、 Plan 53,Arrangement 3 may use Plan 11 & 53 排列方式3可以用11&53方案 Improved heat transfer 增加换热 Reverse pressure capability 压力转换能力 “Back to Back ” seals uses Plan 53背对背密封用53方案,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,Plan 72 (A.4.16,Arrangement 2, w/ Containment Seal (CS) 排列方式2，辅助二次密封 Dual Un-

48、Pressurised (Tandem) Seals 不带压双封 Dry-running secondary containment seal 干运转二次辅助密封 Low pressure nitrogen sweep (purge)低压氮气吹扫 Sweeps primary leakage to collection system 主密封泄漏的东西排放到收集系统里 Dilutes primary leakage to lower emission levels 稀释泄漏的东西 Used in conjunction with Plan 75 or 76 ，与75方案获76方案一起使用,CSV

49、: containment seal vent CSD: containment seal Drain GBI: gas buffer inlet FIL: coalescing filter,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,Plan 74 (A.4.17,Arrangement 3, Non-contacting Seals (NC) 排列方式3，非接触式密封 Dual Pressurised (Double) Gas Barrier Seals 带压 Nitrogen gas barrier 氮气隔离 1.75

50、- 2 bar (25-30 psi) above seal chamber pressure密封腔压力1.75-2bar Zero emissions 零泄漏 Essentially a T2800 panel 2800类型控制面板,GBI: gas buffer inlet GBO: gas buffer outlet (NC) (used only to depressurize,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,Plan 75 (A.4.18,Arrangement 2, w/ Containment Seal

51、 (CS) 排列方案2，二次辅助密封 Dual Un-Pressurised (Tandem) Seals 双无压密封 Dry-running secondary 辅助密封干运转 Condensate collection reservoir (8.6.5.2)冷凝液收集罐 Used when primary seal leakage may condense ( does not completely vaporize) 用于从主密封泄漏出来的可冷凝的工况 May be used in conjunction with Plan 72 或许和72方案一起使用,API 682 2nd Edit

52、ion API 682 第二版New Piping Plans 新的冲洗方案,Plan 76 (A.4.19,Arrangement 2, w/ Containment Seal (CS) 排列方式2，二次辅助密封 Dual Un-Pressurised Seals (Dry-running secondary)双无压密封 Primary leakage routed to flare or vent Used when primary seal leakage will not condense (completely vaporizes) 用于从主密封泄漏出的不可冷凝的工况 Essentially a 48SC or 28LD panel leakage detection May be used in conjunction with Plan 72 或许和72方案一起使用,API 682 2nd Edition API 682 第二版New Piping Plans 新的冲洗方案,密封安装 第三部分,在安装前，不要拆开密封 不要接触或碰撞密封面 将密封面向上放置密封 放在柔软的