钻井泵基础知识PPT课件

《钻井泵基础知识PPT课件》由会员分享，可在线阅读，更多相关《钻井泵基础知识PPT课件（49页珍藏版）》请在金锄头文库上搜索。

1、钻井泵基础知识n n一、钻井泵的结构和特点 n n二、钻井泵工作原理 n n三、钻井泵的使用 n n四、钻井泵的日常维护和检查 n n五、钻井泵常见故障判断及排除方法n n六、钻井泵易损件及其更换方法 一、钻井泵的结构和特点 钻井泵基本组成钻井泵的结构图小齿轮轴总成曲轴总成十字头总成液力端总成排出管路总成排出空气包总成排出空气包总成钻井泵主要特点钻井泵主要特点钻井泵主要特点钻井泵主要特点 动力端动力端 机架采用钢板焊接件，强度高，刚机架采用钢板焊接件，强度高，刚性好，重量轻。性好，重量轻。n n 整体人字齿轮传动，运转平稳整体人字齿轮传动，运转平稳. .n n 合金钢曲轴。可更换的十字头导合金

2、钢曲轴。可更换的十字头导板。板。 n n 采用滚子轴承，提高了运转时的采用滚子轴承，提高了运转时的平稳性和承载能力。平稳性和承载能力。n n 中间拉杆盘根采用先进密封结构，中间拉杆盘根采用先进密封结构，密封效果好。密封效果好。n n 动力端齿轮、轴承、十字头等部动力端齿轮、轴承、十字头等部位采用强制润滑和飞溅润滑相结合位采用强制润滑和飞溅润滑相结合的润滑方式。的润滑方式。n n 应用施必牢防松螺母，拆装方便。应用施必牢防松螺母，拆装方便。液力端液力端n n 液缸采用直通式布液缸采用直通式布置，可使液流平稳、结置，可使液流平稳、结构紧凑、容积效率高。构紧凑、容积效率高。n n 三个液缸具有互换三

3、个液缸具有互换性。性。n n 缸盖和阀盖能快速缸盖和阀盖能快速旋紧，装拆方便。旋紧，装拆方便。n n 吸入阀和排出阀能吸入阀和排出阀能通用互换。通用互换。n n 采用敞开式的活塞采用敞开式的活塞与缸套内腔结构，便于与缸套内腔结构，便于观察。观察。n n 二、钻井泵的工作原理动力机万向轴、皮带等小齿轮轴曲轴十字头总成连 杆液力端总成机械能液体能转动往复运动钻井泵的工作过程钻井泵的基本性能参数 n n泵的理论排量：泵在单位时间内排出的介质体积称为泵的理论平均排量，简称为泵的理论排量，以Q表示。n n泵的工作压力：通常是指泵排出口处单位面积上所受到的液体作用力，简称为泵压，以p表示。n n泵的额定功

4、率和效率：单位时间内动力机传递给泵主动轴的能量，称为泵的输入功率；泵工作于额定冲次时的输入功率称为泵的额定功率，以N表示；单位时间内液体经泵作用后增加的能量称有效功率，也称水功率，以Nr表示；泵的效率是有效功率与输入功率的比值。n n冲次：也称泵冲，指单位时间内活塞的往复次数，以n表示。n n冲程长度：指活塞往复运动的距离，以S表示。三、钻井泵的使用 钻井泵作为钻井作业的重要装备，在工作时向井底输送循环高压钻井液，冲洗井底、破碎岩石、冷却润滑钻头，并将岩屑携带返回地面。 钻井泵使用我们从下面三方面讲：1、钻井泵的安装2、钻井泵的启动3、泵在运转中的监视钻井泵的安装 （一）钻井泵的安装1、 钻井

5、泵应安装在水平或略向液力端倾斜的底座上（倾斜度3），以利于润滑油的流动。2、泵的安装位置应尽量降低，泥浆池的位置应尽量提高，以提高钻井泵的吸入效率。3、 吸入管线布置时应使灌注泵旁通联接，以便于当灌注泵有故障或进行维修时，钻井泵可以继续工作。 皮带轮左右偏差和斜差不大于2mm一根皮带中间挂15kg重物下垂50-60mm左右不平度每米不大于2mm前后不平度每米不大于3mm3、泵的吸入管入口端应高于泥浆池底约300mm，而且吸入管内径必须一致，吸入管的入口端不能正对泥浆池的入口（对泥浆罐也是如此）。4、剪销安全阀必须安装成可直接与泥浆接触，并且将安全阀排出端用无缝钢管直接引到泥浆罐，这条管线应尽可

6、能少一些转折。若转弯应使弯头大于120，不允许把安全阀的排出管线接到泵的吸入管上，在排出管路与安全阀之间不许安装任何型式的闸门。剪销安全阀的阀体上标有每级工作压力的标记，调节压力时，只需按剪销安全阀的阀体上标有每级工作压力的标记，调节压力时，只需按所给压力把剪切销插入相应的孔内。注意：剪销板孔内只能插一个剪所给压力把剪切销插入相应的孔内。注意：剪销板孔内只能插一个剪切销。若缸套活塞尺寸变更，则须相应地调定安全阀压力。不要使用切销。若缸套活塞尺寸变更，则须相应地调定安全阀压力。不要使用内六角扳手、电焊条或其它材料，若这样作将会影响安全阀的压力值，内六角扳手、电焊条或其它材料，若这样作将会影响安全

7、阀的压力值，并可能导致事故的发生。并可能导致事故的发生。There is marked the working pressure of each grade on the There is marked the working pressure of each grade on the body of shear safety valve. When adjusting the pressure, body of shear safety valve. When adjusting the pressure, just insert the shear pin to corresponding

8、 hole according to just insert the shear pin to corresponding hole according to the required pressure. Note: each time you can only insert the required pressure. Note: each time you can only insert one shear pin in hole plate. If the cylinder liner and one shear pin in hole plate. If the cylinder li

9、ner and piston are changed, the pressure of safety valve also should piston are changed, the pressure of safety valve also should be adjusted accordingly. But do not use Allen key (hexagon be adjusted accordingly. But do not use Allen key (hexagon ring spanner), welding rod and some other things as

10、shear ring spanner), welding rod and some other things as shear pin, because it will influence the pressure of safety valve, pin, because it will influence the pressure of safety valve, even lead to an accident. even lead to an accident. 牢固的支撑所有吸入和排出管线，不使它们受到不必要的应力，牢固的支撑所有吸入和排出管线，不使它们受到不必要的应力，同时也是为了

11、减少振动，决不可由于没有足够的支撑而让管线悬挂在同时也是为了减少振动，决不可由于没有足够的支撑而让管线悬挂在泵上。泵上。 Firmly support all the suction and discharge pipelines to Firmly support all the suction and discharge pipelines to make sure that they do not suffer the unnecessary stress, at make sure that they do not suffer the unnecessary stress, at t

12、he same time, to decreases vibration. It is not allowed to the same time, to decreases vibration. It is not allowed to make pipelines suspend on pump without enough supports.make pipelines suspend on pump without enough supports.泵的启动start of pump 启动前的准备工作preparation before start启动前的准备工作启动前的准备工作Prepa

13、ration before startPreparation before start 检查动力端机架底部，放空润滑油并清洗油池。然后对照泵机架铭牌上对润检查动力端机架底部，放空润滑油并清洗油池。然后对照泵机架铭牌上对润滑油的要求，将一定牌号和数量的润滑油加入动力端。滑油的要求，将一定牌号和数量的润滑油加入动力端。Check the bottom of power end; empty the lubrication and clean the oil Check the bottom of power end; empty the lubrication and clean the oil

14、sump. Then according to the lubrication requirement marked in the sump. Then according to the lubrication requirement marked in the nameplate on pump frame, fill the power end with adequate lubrication.nameplate on pump frame, fill the power end with adequate lubrication. 检查十字头与上导板的间隙是否符合要求。检查十字头与上导

15、板的间隙是否符合要求。Check the clearance between the crosshead and upper guide to make sure Check the clearance between the crosshead and upper guide to make sure that it is proper.that it is proper. 检查喷淋泵水箱内冷却润滑液是否达到要求。检查喷淋泵水箱内冷却润滑液是否达到要求。Check the cooling lubricant in the water tank of spray pump to make Ch

16、eck the cooling lubricant in the water tank of spray pump to make sure that it is propersure that it is proper 检查所有螺纹联接是否紧固以及泵内是否有杂物。检查所有螺纹联接是否紧固以及泵内是否有杂物。Check all the thread connections to make sure they are tightened and Check all the thread connections to make sure they are tightened and check f

17、or any sundries in the pump.check for any sundries in the pump. 检查泥浆管线上的所有阀门是否置于正确位置。检查泥浆管线上的所有阀门是否置于正确位置。Check all valves on mud line to make sure they are on proper Check all valves on mud line to make sure they are on proper status.status. 检查排出空气包充气压力是否达到检查排出空气包充气压力是否达到40.5MPa40.5MPa的规定值。的规定值。Che

18、ck the pulse dampener to make sure its charge pressure Check the pulse dampener to make sure its charge pressure gets to 40.5MPa.gets to 40.5MPa. 打开喷淋泵系统和灌注系统的进排液阀门。打开喷淋泵系统和灌注系统的进排液阀门。Open the inlet and outlet valves of spray pump and charge Open the inlet and outlet valves of spray pump and charge

19、pump.pump. 检查剪销安全阀和压力表是否齐全灵敏。安全阀的压力设置是否检查剪销安全阀和压力表是否齐全灵敏。安全阀的压力设置是否符合要求。符合要求。Check the shear safety valve and the pressure gauge to make Check the shear safety valve and the pressure gauge to make sure they are ready and sensitive, check whether the safety sure they are ready and sensitive, check wh

20、ether the safety valves pressure setting is correct or not.valves pressure setting is correct or not. 向吸入管路腔内灌满水或泥浆，排净空气。向吸入管路腔内灌满水或泥浆，排净空气。Fill the chamber of suction lines with water or mud to Fill the chamber of suction lines with water or mud to discharge all air.discharge all air.启动start 应以低速起动

21、，逐渐增速，以提高容积效率。应以低速起动，逐渐增速，以提高容积效率。Start with low speed and speed up gradually to improve the volumetric Start with low speed and speed up gradually to improve the volumetric efficiency.efficiency. 如果需要高泵速时，就必须使用灌注泵。如果需要高泵速时，就必须使用灌注泵。If high pump speed is needed, the charge pump must be used.If high

22、pump speed is needed, the charge pump must be used. 检查动力端润滑油压表读数是否正常。检查动力端润滑油压表读数是否正常。Check the reading of lubrication pressure gauge at power end to see whether Check the reading of lubrication pressure gauge at power end to see whether it is proper or not.it is proper or not. 注意检查各部温度，不得有局部过热现象。注意

23、检查各部温度，不得有局部过热现象。Check the temperature of each part. There are should no local overheating. Check the temperature of each part. There are should no local overheating. 启动泵必须与有关操作及检查人员取得联系。启动泵必须与有关操作及检查人员取得联系。When start the pump, you shall contact with related operator and inspector.When start the pum

24、p, you shall contact with related operator and inspector. 开泵时检查人员必须注视压力表的压力，泥浆未返回地面前不允许离开气开泵时检查人员必须注视压力表的压力，泥浆未返回地面前不允许离开气开关。开关。When start the mud pump, the operator should notice the pressure showed When start the mud pump, the operator should notice the pressure showed on the pressure gauge. If th

25、e mud does not return to the ground, the on the pressure gauge. If the mud does not return to the ground, the operator should not leave the control panel (air switch of clutch).operator should not leave the control panel (air switch of clutch). 挂泵离合器时，采用二次启动法，这样可使泵得到活动的机会，也可以观挂泵离合器时，采用二次启动法，这样可使泵得到活

26、动的机会，也可以观察泵在启动中有无障碍，如一切正常，即可挂上离合器。察泵在启动中有无障碍，如一切正常，即可挂上离合器。When engage the pump clutch, prefer adopt twice start method, this can When engage the pump clutch, prefer adopt twice start method, this can make the pump get the chance to act and also see whether there is anything make the pump get the ch

27、ance to act and also see whether there is anything wrong. If there is nothing wrong, engage the clutch finally.wrong. If there is nothing wrong, engage the clutch finally.泵在运转中的观察泵在运转中的观察Inspection (observation) during operation ( running)Inspection (observation) during operation ( running)检查活塞杆和中间拉

28、杆卡箍是否有不正常响声；检查液缸上的所有螺母检查活塞杆和中间拉杆卡箍是否有不正常响声；检查液缸上的所有螺母以及阀盖和缸盖是否有松动现象。如发现不正常现象，查明原因，及时处理。以及阀盖和缸盖是否有松动现象。如发现不正常现象，查明原因，及时处理。Check whether the clamp for piston rod and extension rod connection Check whether the clamp for piston rod and extension rod connection has some abnormal sound; check whether all

29、the nuts on cylinder has some abnormal sound; check whether all the nuts on cylinder block and valve cover and cylinder cover are loosen or not. If block and valve cover and cylinder cover are loosen or not. If there are some abnormality, find out the reason and eliminate them there are some abnorma

30、lity, find out the reason and eliminate them immediately. immediately. 检查各高压密封处是否有泄漏现象，泵阀和缸套处是否有刺漏声，如发检查各高压密封处是否有泄漏现象，泵阀和缸套处是否有刺漏声，如发现问题，应及时处理。现问题，应及时处理。Check whether the high pressure seal have leakage or not, and Check whether the high pressure seal have leakage or not, and whether the pump valve

31、and cylinder liner have any washout sound. whether the pump valve and cylinder liner have any washout sound. If there is something wrong, resolve it immediately. If there is something wrong, resolve it immediately. 注意泵压变化，发现异常情况妥善处理。注意泵压变化，发现异常情况妥善处理。Notice the change of the pump pressure. If there

32、is something Notice the change of the pump pressure. If there is something wrong, handle it immediatelywrong, handle it immediately n n注意喷淋泵的供水情况是否正常。注意喷淋泵的供水情况是否正常。n nNotice whether the water supply of spray pump is Notice whether the water supply of spray pump is normal or not.normal or not.n n 注意

33、各轴承部位、十字头导板以及其它有相对运动的注意各轴承部位、十字头导板以及其它有相对运动的部位的温度是否过高或有异常现象。部位的温度是否过高或有异常现象。n nNotice the temperature of each part of bearing, Notice the temperature of each part of bearing, crosshead guide and other parts with movement is too crosshead guide and other parts with movement is too high or has any abn

34、ormal phenomenon.high or has any abnormal phenomenon.n n 在机架后部，动力端润滑油路的压力表读数是否正常。在机架后部，动力端润滑油路的压力表读数是否正常。n nAt the back of frame, check whether the pressure At the back of frame, check whether the pressure gauges reading of lubrication for power end is proper or gauges reading of lubrication for pow

35、er end is proper or not not 钻井泵的日常维护和检查 正确和及时地对钻井泵进行维护保养，是保证钻井正确和及时地对钻井泵进行维护保养，是保证钻井泵正常工作，延长寿命的必要措施。对于任何一台泵的泵正常工作，延长寿命的必要措施。对于任何一台泵的使用，都应重视这一环节。使用，都应重视这一环节。Maintaining the drilling pump correctly and duly is the Maintaining the drilling pump correctly and duly is the necessary measure to ensure it w

36、orking properly and necessary measure to ensure it working properly and lengthen its servicing life. To any drilling pump, it is lengthen its servicing life. To any drilling pump, it is very important. very important. uu每天的维护保养每天的维护保养 daily maintenance daily maintenance uu每星期的维护保养每星期的维护保养 weekly mai

37、ntenanceweekly maintenanceuu每月的维护保养每月的维护保养 monthly maintenancemonthly maintenanceuu每年的维护保养每年的维护保养 yearly maintenanceyearly maintenanceuu在维护保养中尚须注意的其它事项在维护保养中尚须注意的其它事项 uuSome other items should be paid attentionSome other items should be paid attention每天的维护保养daily maintenancen n停泵后检查动力端的油位。停泵后检查动力端的油

38、位。n nCheck the oil level of the power end after Check the oil level of the power end after stoprunningstoprunningn n观察缸套与活塞的工作情况。若发现漏出来的泥浆超出正常限度时，则须观察缸套与活塞的工作情况。若发现漏出来的泥浆超出正常限度时，则须更换新缸套、活塞。更换新缸套、活塞。n nObserve the working condition of cylinder liner and piston. If the mud Observe the working conditio

39、n of cylinder liner and piston. If the mud leaking out is over the limit, It needs to change a new cylinder liner and leaking out is over the limit, It needs to change a new cylinder liner and piston. piston. n n检查缸套腔，若有大量泥浆沉淀，应加以清理。检查缸套腔，若有大量泥浆沉淀，应加以清理。n nCheck the chamber of cylinder liner. If the

40、re is too much mud deposit, Check the chamber of cylinder liner. If there is too much mud deposit, clean it.clean it.n n检查喷淋泵水箱内水是否够用，并及时补充，冷却水有污染时加以更换，检查喷淋泵水箱内水是否够用，并及时补充，冷却水有污染时加以更换，并同时清理水箱卫生。并同时清理水箱卫生。n nCheck whether the water tank of spray pump is enough or not and Check whether the water tank

41、of spray pump is enough or not and replenish in time. When the cooling water is polluted, change it and clean replenish in time. When the cooling water is polluted, change it and clean the water tank.the water tank.n n检查排出空气包的充气压力，是否符合要求。检查排出空气包的充气压力，是否符合要求。n nCheck whether the charge pressure of di

42、scharge dampener is proper or Check whether the charge pressure of discharge dampener is proper or not.not.n n检查剪销安全阀的可靠性，必要时应予以更换。检查剪销安全阀的可靠性，必要时应予以更换。n nCheck the shear safety valves reliability and change it when necessary.Check the shear safety valves reliability and change it when necessary.n n

43、检查润滑油泵压力表变化情况。如发现压力很小（检查润滑油泵压力表变化情况。如发现压力很小（0.035MPa0.035MPa）或无压）或无压力，应及时检查过滤器是否有堵塞现象。力，应及时检查过滤器是否有堵塞现象。n nCheck the reading of pressure gauge of lubrication pump. If the Check the reading of pressure gauge of lubrication pump. If the pressure is very smallpressure is very small（0.035MPa0.035MPa）or

44、even without pressure, check or even without pressure, check whether the filter is jammed or not in time. whether the filter is jammed or not in time. n n每天将活塞杆卡箍松开，把活塞转动四分之一圈左右，然后再上紧卡每天将活塞杆卡箍松开，把活塞转动四分之一圈左右，然后再上紧卡箍。箍。n nLoose the piston rod clamp everyday. Turn the piston a quarter Loose the piston

45、 rod clamp everyday. Turn the piston a quarter round and then tighten the clamp.round and then tighten the clamp.n n在上紧缸盖与阀盖前，先在其丝扣内填涂润滑脂，且在每在上紧缸盖与阀盖前，先在其丝扣内填涂润滑脂，且在每4 4小时时间小时时间内，检查一次是否有松动现象出现。内，检查一次是否有松动现象出现。 n nBefore installing the cylinder cover and valve cover, first fill the Before installing

46、the cylinder cover and valve cover, first fill the thread with grease. Check whether it loose or not every 4 hours.thread with grease. Check whether it loose or not every 4 hours.n n经常观察阀盖、缸盖、缸套密封（含耐磨盘与液缸间的密封）的报警经常观察阀盖、缸盖、缸套密封（含耐磨盘与液缸间的密封）的报警孔，如有泥浆流出，就应及时的更换相应的密封圈。孔，如有泥浆流出，就应及时的更换相应的密封圈。n nObserve t

47、he alarm hole of valve cover, cylinder cover and cylinder Observe the alarm hole of valve cover, cylinder cover and cylinder liner seal (including the seal between wear plate and cylinder). If liner seal (including the seal between wear plate and cylinder). If the mud flows out, replace correspondin

48、g seal ring in time. the mud flows out, replace corresponding seal ring in time. 每星期的维护保养每星期的维护保养每星期的维护保养每星期的维护保养 weekly maintenance weekly maintenance n n每周拆卸阀盖、缸盖一次，除去污泥，清洗干净，涂上二硫化钼复合钙每周拆卸阀盖、缸盖一次，除去污泥，清洗干净，涂上二硫化钼复合钙基润滑脂，检查阀导向套的内套，如已明显磨损（阀导向杆与导套间的间隙基润滑脂，检查阀导向套的内套，如已明显磨损（阀导向杆与导套间的间隙超过超过3mm3mm）应将其换掉。

49、）应将其换掉。n nDisassemble the valve cover and cylinder cover once a week. Get rid of the mud and Disassemble the valve cover and cylinder cover once a week. Get rid of the mud and clean it. Then coat it with compound molybdenum disulfide calcium base grease. clean it. Then coat it with compound molybden

50、um disulfide calcium base grease. Check the inner bushing of valve guide. If it has been obviously worn (the clearance Check the inner bushing of valve guide. If it has been obviously worn (the clearance between valve stem and guide bushing should not more than 3mm), replace it between valve stem an

51、d guide bushing should not more than 3mm), replace it immediately. immediately. n n检查阀和阀座的使用情况，把磨损严重或刺坏了的阀体，阀胶皮和阀座检查阀和阀座的使用情况，把磨损严重或刺坏了的阀体，阀胶皮和阀座换掉（更换阀座时应注意同时更换阀体）。检查阀弹簧，把折断或丧失弹力换掉（更换阀座时应注意同时更换阀体）。检查阀弹簧，把折断或丧失弹力的阀弹簧及时换掉。的阀弹簧及时换掉。n nCheck the condition of valve and valve seat. Replace the worn and wa

52、shout valve Check the condition of valve and valve seat. Replace the worn and washout valve body, valve rubber and valve seat (notice: when replace the valve seat, replace the body, valve rubber and valve seat (notice: when replace the valve seat, replace the valve body at the same time). Check the

53、valve spring, replace the broken or miss valve body at the same time). Check the valve spring, replace the broken or miss elasticity spring in time.elasticity spring in time.n nn n检查活塞锁紧螺母，若遇腐蚀或损坏应换掉（因为一般上检查活塞锁紧螺母，若遇腐蚀或损坏应换掉（因为一般上紧过三次以后的螺母，镶在其内的密封圈已失去锁紧能力）紧过三次以后的螺母，镶在其内的密封圈已失去锁紧能力）。n nCheck the pist

54、on lock nut. When it is cankered or worn, Check the piston lock nut. When it is cankered or worn, change it, because generally, if a nut is screwed down three change it, because generally, if a nut is screwed down three times, the sealing ring inlayed in it shall lose the seal function. times, the s

55、ealing ring inlayed in it shall lose the seal function. n n从排泄孔盖的丝堵处放一次水，直至见油为止。从排泄孔盖的丝堵处放一次水，直至见油为止。 n nDrain water from the screw plug on the drain hole cover until Drain water from the screw plug on the drain hole cover until oil out.oil out.n n检查并清洗润滑油泵管线中的滤网一次。检查并清洗润滑油泵管线中的滤网一次。n nCheck and cle

56、an the filter strainer of lubrication pump pipeline Check and clean the filter strainer of lubrication pump pipeline once.once.每月的维护保养每月的维护保养每月的维护保养每月的维护保养 monthly maintenancemonthly maintenance 检查液力端的所有双头螺栓和螺母。例如缸盖法兰螺母，液缸与机检查液力端的所有双头螺栓和螺母。例如缸盖法兰螺母，液缸与机架联接的螺母，以及吸入管路、排出管路的联接螺栓、螺母等。如果架联接的螺母，以及吸入管路、排出管

57、路的联接螺栓、螺母等。如果出现松动，须按规定扭矩重新上紧。出现松动，须按规定扭矩重新上紧。Check all the studs and nuts of power end. Such as the flange nut of Check all the studs and nuts of power end. Such as the flange nut of cylinder cover, the nut connected with cylinder and frame, and the bolts and cylinder cover, the nut connected with c

58、ylinder and frame, and the bolts and nuts in suction pipeline and discharge pipeline. If there are some looses, nuts in suction pipeline and discharge pipeline. If there are some looses, tighten them according to prescribed torque. tighten them according to prescribed torque. 检查中间拉杆填料盒内的密封圈，若已磨损须更换，

59、一般每三个月检查中间拉杆填料盒内的密封圈，若已磨损须更换，一般每三个月至少换一次。更换时应注意油封方位至少换一次。更换时应注意油封方位 。Check the packing ring of extension rod in the stuffing box. If it is worn, Check the packing ring of extension rod in the stuffing box. If it is worn, replace it at least once three months. When replacement, notice the azimuth rep

60、lace it at least once three months. When replacement, notice the azimuth of the packing.of the packing. 拆卸和清洗装在排出滤网里的滤筒。拆卸和清洗装在排出滤网里的滤筒。Disassemble and clean the filter strainer in the discharge filter.Disassemble and clean the filter strainer in the discharge filter. 每六个月换掉动力端油池和十字头沉淀油槽内的脏油，并同时清理每六

61、个月换掉动力端油池和十字头沉淀油槽内的脏油，并同时清理这些油槽。这些油槽。Change the used oil in sump of power end and in crosshead oil deposit pool Change the used oil in sump of power end and in crosshead oil deposit pool once per six months and clean them at the same time. once per six months and clean them at the same time. 每年的维护保养

62、每年的维护保养 yearly maintenancen n检查十字头导板是否松动，十字头运转间隙是否符合规定要求，可在导板检查十字头导板是否松动，十字头运转间隙是否符合规定要求，可在导板下加垫片来调整。在拆卸曲轴总成时，可将十字头旋转下加垫片来调整。在拆卸曲轴总成时，可将十字头旋转180180再进行使用。再进行使用。n nCheck whether the crosshead guide is loosened or not, check whether Check whether the crosshead guide is loosened or not, check whether th

63、e clearance is proper or not. If it is not, add shim below the guide to the clearance is proper or not. If it is not, add shim below the guide to adjust. When disassemble the crankshaft assembly, the crosshead can adjust. When disassemble the crankshaft assembly, the crosshead can be turned 180 and

64、reuse it. be turned 180 and reuse it. n n推荐每隔两年或三年对整个泵进行一次全面检查。检查主轴承、偏心轮轴推荐每隔两年或三年对整个泵进行一次全面检查。检查主轴承、偏心轮轴承、十字头轴承、小齿轮轴轴承是否磨损或损坏，若不能继续使用，则须承、十字头轴承、小齿轮轴轴承是否磨损或损坏，若不能继续使用，则须另换新的。另换新的。n nIt is recommended that check thoroughly the whole pump every two or It is recommended that check thoroughly the whole

65、pump every two or three years. Check whether the main bearing, eccentric (crank) bearing, three years. Check whether the main bearing, eccentric (crank) bearing, crosshead bearing, pinion shaft bearing are worn or not. If they can not crosshead bearing, pinion shaft bearing are worn or not. If they

66、can not use any more, replace them with new bearing.use any more, replace them with new bearing.n n检查齿轮的磨损情况，若磨损严重，须将曲轴和小齿轮轴同时调头安装，检查齿轮的磨损情况，若磨损严重，须将曲轴和小齿轮轴同时调头安装，利用齿面未磨损的一面。利用齿面未磨损的一面。n nCheck the wear condition of gears. If they are worn, install the Check the wear condition of gears. If they are

67、worn, install the crankshaft and pinion shaft by turn over the ends to use the unworn crankshaft and pinion shaft by turn over the ends to use the unworn face of gears. face of gears. 在维护保养中尚须注意的其它事项在维护保养中尚须注意的其它事项在维护保养中尚须注意的其它事项在维护保养中尚须注意的其它事项other attentions during the maintenance processother att

68、entions during the maintenance process n n上卡箍前，必须将上卡箍前，必须将2525的锥面擦干净。的锥面擦干净。n nBefore install the clamp, clean the 25 taper faceBefore install the clamp, clean the 25 taper facen n更换缸套时，必须将缸套密封圈一起换掉。更换缸套时，必须将缸套密封圈一起换掉。n nWhen replace the cylinder liner, replace the seal ring of liner When replace th

69、e cylinder liner, replace the seal ring of liner at the same timeat the same timen n冬季停泵后，须将阀腔及缸套内的泥浆放尽并冲洗干净。冬季停泵后，须将阀腔及缸套内的泥浆放尽并冲洗干净。n nWhen the pump is stopped in winter, discharge the mud in When the pump is stopped in winter, discharge the mud in valve pot and liner and flush them clean. valve p

70、ot and liner and flush them clean. n n泵各检查窗孔应注意盖好，以防灰砂等混入润滑油内。泵各检查窗孔应注意盖好，以防灰砂等混入润滑油内。n nCover all man holes well to avoid the sand or dust enter the Cover all man holes well to avoid the sand or dust enter the lubrication. lubrication. n n排出空气包只能充以氮气等惰性气体，严禁充入易燃、易爆气排出空气包只能充以氮气等惰性气体，严禁充入易燃、易爆气体。如氧气、

71、氢气等。体。如氧气、氢气等。n nThe air bladder of dampener can just be filled with inert The air bladder of dampener can just be filled with inert gases such as nitrogen. It is forbidden to fill it with flammable gases such as nitrogen. It is forbidden to fill it with flammable and explosive gas, such as oxygen,

72、hydrogen, etc. and explosive gas, such as oxygen, hydrogen, etc. 钻井泵常见故障判断及排除方法钻井泵常见故障判断及排除方法Frequent failure and solutionFrequent failure and solution 液力端故障液力端故障 故故 障障原原 因因排排 除除 方方 法法 压力表的压力下降。排压力表的压力下降。排量减小或不排泥浆。量减小或不排泥浆。吸入管路密封不严，空气进吸入管路密封不严，空气进入泵内。吸入滤网堵死。入泵内。吸入滤网堵死。拧紧吸入管法兰螺栓或更换垫拧紧吸入管法兰螺栓或更换垫片。停泵，

73、清除吸入滤网杂物片。停泵，清除吸入滤网杂物液体排出不均匀，有忽液体排出不均匀，有忽忽小的冲击。压力表的忽小的冲击。压力表的压力变化很大，吸入管压力变化很大，吸入管路发出呼呼声。路发出呼呼声。一个活塞或一个阀磨损一个活塞或一个阀磨损严重或者已经损坏。严重或者已经损坏。泵缸内进空气。泵缸内进空气。更换已坏活塞；打开阀盖，更换已坏活塞；打开阀盖，检查阀有无损坏或卡死。检查阀有无损坏或卡死。检查吸入管路及阀盖是否严密检查吸入管路及阀盖是否严密缸套处有剧烈的敲击声。缸套处有剧烈的敲击声。活塞螺母松掉。缸逃压盖松活塞螺母松掉。缸逃压盖松动。吸入不良，产生水击。动。吸入不良，产生水击。拧紧活塞螺母。拧紧缸套

74、压拧紧活塞螺母。拧紧缸套压盖。检查吸入不良的原因。盖。检查吸入不良的原因。阀盖、缸盖以及缸套密阀盖、缸盖以及缸套密封处显示孔漏泥浆。封处显示孔漏泥浆。阀盖、缸盖未上紧。阀盖、缸盖未上紧。密封圈损坏。密封圈损坏。上紧阀盖、缸盖。上紧阀盖、缸盖。更换密封圈。更换密封圈。排出空气包充不进气体或排出空气包充不进气体或充气后很快泄漏。充气后很快泄漏。充气接头堵死。空气包气囊充气接头堵死。空气包气囊已破。针形截止阀密封不严已破。针形截止阀密封不严清除接头内的杂物。更换气清除接头内的杂物。更换气囊。修理或更换针形截止阀。囊。修理或更换针形截止阀。柴油机负荷大。柴油机负荷大。排出滤筒堵塞。排出滤筒堵塞。拆下滤

75、筒，清除杂物，洗净。拆下滤筒，清除杂物，洗净。动力端故障故故 障障原原 因因排排 除除 方方 法法轴承高热轴承高热1.1.油管或油孔堵死。油管或油孔堵死。2.2.润滑油太脏。润滑油太脏。3.3.滚动轴承磨损或损坏。滚动轴承磨损或损坏。1.1.清理油管及油孔。清理油管及油孔。2.2.更换新油。更换新油。3.3.拆开轴承，查明原拆开轴承，查明原因更换轴承。因更换轴承。动力端有敲击声动力端有敲击声1.1.十字头导板已磨损。十字头导板已磨损。2.2.轴承磨损。轴承磨损。3.3.导板松动。导板松动。4.4.液力端有水击现象。液力端有水击现象。1.1.调整间隙或更换已调整间隙或更换已磨损的导板。磨损的导板

76、。2.2.更换轴承。更换轴承。3.3.上紧导板螺钉。上紧导板螺钉。4.4.改善吸入性能。改善吸入性能。钻井泵易损件及其更换方法Consumable and replacement 阀与阀座阀与阀座valve and valve seatn n取下阀盖、缸盖、缸盖堵头和定位盘，抽出插板总成，取出阀杆导向取下阀盖、缸盖、缸盖堵头和定位盘，抽出插板总成，取出阀杆导向器（下）和阀弹簧以及阀体等（含阀胶皮和阀螺母等）。用随机配置的液器（下）和阀弹簧以及阀体等（含阀胶皮和阀螺母等）。用随机配置的液压拔阀器专用工具，分别将上部排出阀座和下部吸入阀座拔出。压拔阀器专用工具，分别将上部排出阀座和下部吸入阀座拔出

77、。n nRemove the valve cover, cylinder cover, cylinder plug and locating disk; Remove the valve cover, cylinder cover, cylinder plug and locating disk; draw out the inserter assembly; take out the valve draw out the inserter assembly; take out the valve guide(downguide(down), valve ), valve spring and

78、 valve body, spring and valve body, etc.(includingetc.(including the valve rubber and valve nut, etc.). the valve rubber and valve nut, etc.). pull out the upper discharge valve seat and the lower suction valve seat pull out the upper discharge valve seat and the lower suction valve seat by hydrauli

79、c valve puller.by hydraulic valve puller.n n清洗上下阀座孔配合面（使用优质清洗剂），确认各阀座孔十分清洁清洗上下阀座孔配合面（使用优质清洗剂），确认各阀座孔十分清洁并干燥（无脏物、油脂、防锈剂等）。用金刚砂纸磨去表面上所有毛刺，并干燥（无脏物、油脂、防锈剂等）。用金刚砂纸磨去表面上所有毛刺，砂纸要沿阀座孔循环运动。砂纸要沿阀座孔循环运动。n nClean the fitting surface of upper and lower valve seat hole (pump deck) Clean the fitting surface of upp

80、er and lower valve seat hole (pump deck) and make sure all the valve seat hold clean and dry without dirty, grease and make sure all the valve seat hold clean and dry without dirty, grease and antirust. Rub out all burrs on the surface with emery paper, notice and antirust. Rub out all burrs on the

81、surface with emery paper, notice that the emery paper should move circularly along the valve seat hole that the emery paper should move circularly along the valve seat hole (pump deck). (pump deck). n n彻底清洗并干燥阀座，把吸入和排出阀座装到阀腔孔内装上阀体，用彻底清洗并干燥阀座，把吸入和排出阀座装到阀腔孔内装上阀体，用铜棒榔头敲击导向杆上部，使阀座到位。再装上阀弹簧及其它零件。铜棒榔头敲击导向

82、杆上部，使阀座到位。再装上阀弹簧及其它零件。n nClean and dry the valve seat and deck. Install the suction valve and Clean and dry the valve seat and deck. Install the suction valve and discharge valve seat into the valve pot and then the valve body. Knock discharge valve seat into the valve pot and then the valve body. K

83、nock the upper part of the guide rod with hammer or copper rod to make the the upper part of the guide rod with hammer or copper rod to make the valve seat get to its position. At last, install the valve spring and some valve seat get to its position. At last, install the valve spring and some other

84、 components. other components. 液力端hydraulic end液力端装配图液力端装配图液力端装配图液力端装配图 assembly of hydraulic endassembly of hydraulic end缸套、活塞）cylinder liner and pistonn n取下喷淋管总成、卡箍，将十字头中间拉杆通过盘泵移至泵的后死点取下喷淋管总成、卡箍，将十字头中间拉杆通过盘泵移至泵的后死点位置，用铁锤敲击缸套压盖逆时针旋转松开，使其退出，与此同时，通过位置，用铁锤敲击缸套压盖逆时针旋转松开，使其退出，与此同时，通过缸套锁紧环的作用将缸套缸套锁紧环的作用将

85、缸套- -活塞一并从液缸耐磨盘孔中带出，用随机配置的活塞一并从液缸耐磨盘孔中带出，用随机配置的缸套吊装工具吊下。缸套吊装工具吊下。n nDisassemble the spray wash line assembly and clamp. Pull the crosshead Disassemble the spray wash line assembly and clamp. Pull the crosshead extension rod to the back dead center position through cranking. Knock extension rod to th

86、e back dead center position through cranking. Knock the liner clamping plate with hammer to loose it in the liner clamping plate with hammer to loose it in contrarotationcontrarotation and and take it down. At the same time, take out the cylinder liner and piston take it down. At the same time, take

87、 out the cylinder liner and piston form the wearable disk hole through the effect of liner retainer with the form the wearable disk hole through the effect of liner retainer with the liner hoisting device. liner hoisting device. n n组装时，首先清洗活塞杆和活塞，务使其上面无毛刺和划痕。将活塞组装时，首先清洗活塞杆和活塞，务使其上面无毛刺和划痕。将活塞密封圈装到活塞芯

88、的槽内，把活塞装到活塞杆上，注意不要让活塞密封圈密封圈装到活塞芯的槽内，把活塞装到活塞杆上，注意不要让活塞密封圈滑脱。旋紧活塞杆上的螺母。在缸套内圆和活塞外圆上涂抹润滑脂。检查滑脱。旋紧活塞杆上的螺母。在缸套内圆和活塞外圆上涂抹润滑脂。检查活塞杆和中间拉杆端部，务使其上面清洁无毛刺。把活塞杆装进缸套里，活塞杆和中间拉杆端部，务使其上面清洁无毛刺。把活塞杆装进缸套里，使活塞杆在缸套后面保持对中，用硬木或专用工具将活塞打进缸套内。使活塞杆在缸套后面保持对中，用硬木或专用工具将活塞打进缸套内。n nWhen assembly, first clean the piston rod and pisto

89、n to make sure they When assembly, first clean the piston rod and piston to make sure they without burr and nick. Put the piston sealing ring to the groove of piston without burr and nick. Put the piston sealing ring to the groove of piston core and then put the piston on the piston rod. Notice that

90、 the piston core and then put the piston on the piston rod. Notice that the piston sealing ring should not be surged. Screw down the bolts on the piston sealing ring should not be surged. Screw down the bolts on the piston rod. coat the inner surface of liner and outer surface of piston with rod. co

91、at the inner surface of liner and outer surface of piston with grease. Check the end of the piston rod and extension rod to make sure grease. Check the end of the piston rod and extension rod to make sure they without burr. Put the piston into the cylinder liner; make the piston they without burr. P

92、ut the piston into the cylinder liner; make the piston rod in the center at the back of the cylinder liner. Then knock the piston rod in the center at the back of the cylinder liner. Then knock the piston into the cylinder liner with hardwood or special tools. into the cylinder liner with hardwood o

93、r special tools. n n把把缸缸套套密密封封圈圈装装到到耐耐磨磨盘盘的的沉沉孔孔内内。用用润润滑滑脂脂薄薄薄薄涂涂在在缸缸套套压压盖盖的的内内表表面面，然然后后从从后后部部套套到到缸缸套套上上。将将两两半半缸缸套套锁锁紧紧环环装装在在缸缸套套槽槽内内，用用O O形形圈圈把把两两半半缸缸套套锁锁紧紧环环箍箍住住。用用吊吊具具从从缸缸套套上上部部吊吊住住缸缸套套。在在缸缸套套压压盖盖螺螺纹纹上上涂涂抹抹润润滑滑脂脂。把把缸缸套套旋旋压压到到缸缸套套法法兰兰内内，旋旋紧紧缸缸套套压压盖盖，使使缸缸套套端端面面 贴贴到到位位为为止止，用用锤锤头头把把缸缸套套压压盖盖敲敲紧紧。通通过过盘

94、盘泵泵使使十十字字头头中中间间拉拉杆杆向向前前死死点点方方向向移移动动，要要注注意意：在在十十字字头头中中间间拉拉杆杆接接近近活活塞塞杆杆端端部部时时，不不得得损损坏坏活活塞塞杆杆端端部部的的定定位位凸凸台台，要要支支住住活活塞塞杆杆使使它它进进入入到中到中间间拉杆的定位孔内。然后装入卡箍。拉杆的定位孔内。然后装入卡箍。n nPut Put the the cylinder cylinder liner liner sealing sealing ring ring into into the the countersink countersink groove groove of of we

95、arable wearable disk; disk; daub daub the the inner inner surface surface of of cylinder cylinder liner liner clamping clamping plate plate (gland) (gland) with with proper proper grease, grease, and and then then put put it it on on the the cylinder cylinder liner liner from from the the back; back

96、; install install the the two two halves halves liner liner lock lock ring ring into into the the groove groove of of liner liner and and clamp clamp them them with with O-O-ring; ring; hoist hoist the the cylinder cylinder liner liner from from the the upper upper part; part; daub daub grease greas

97、e to to the the liner liner gland gland thread; thread; put put the the cylinder cylinder liner liner into into the the flange flange of of cylinder cylinder liner liner and and screw screw down down the the liner liner gland gland until until the the end end is is on on its its position position an

98、d and knock knock the the liner liner gland gland to to tighten tighten it it with with hammer; hammer; move move the the crosshead crosshead extension extension rod rod to to the the front front dead dead center center position position through through cranking. cranking. Notice Notice that: that:

99、when when the the crosshead crosshead extension extension rod rod is is close close to to the the end end of of the the piston piston rod, rod, it it should should not not damage damage the the locating locating convex convex part part of of the the piston piston rod rod end. end. Support Support th

100、e the piston piston rod rod to to make make it it into into the the locating locating hole hole of of extension extension rod, rod, and and then then install install the the clamp. clamp. n n装装卡卡箍箍之之前前，须须将将挡挡泥泥板板装装在在中中间间拉拉杆杆的的端端部部，把把卡卡箍箍卡卡住住活活塞塞杆杆和和中中间间拉拉杆杆端端部部法法兰兰的的斜斜面面上上。上上紧紧螺螺栓栓。然然后后在在缸缸套套后后部部装装上

101、上缸缸套套端端盖。盖。 n nBefore Before install install the the clamp, clamp, install install the the mud mud baffle baffle at at the the end end of of the the extension extension rod. rod. Clamp Clamp the the clamp clamp at at the the inclined inclined (taper) (taper) part part of of the the piston piston rod

102、 rod end end and and extension extension rod rod end, end, screw screw down down the the bolts bolts and and then then install install the the liners liners end end cover at the back of liner.cover at the back of liner.n n若若活活塞塞杆杆和和卡卡箍箍都都是是新新的的，在在卡卡箍箍两两瓣瓣的的开开口口处处有有大大约约1/21/2（13mm13mm）的的间间隙隙，以以保保证证活活

103、塞塞杆杆端端面面形形成成良良好好的的金金属属对对金金属属联联接接。当当磨磨损损后后，两两瓣瓣将将趋趋于于接接近近。如如果果已已经经没没有有间间隙隙，则则卡卡箍箍不不起起作作用用，此此时时就就应应更更换换卡箍。卡箍。n nIf If the the piston piston rod rod and and clamp clamp are are new, new, there there should should be be a a 1/21/2（13mm13mm）gap gap between between two two halves halves of of the the clam

104、p clamp to to make make sure sure the the end end face face of of the the piston piston rod rod have have a a good good connection connection of of metal metal to to metal. metal. When When they they are are worn worn out, out, the the two two halves halves should should close close gradually. gradu

105、ally. If If there there is is no no gap, gap, the the clamp clamp cannot cannot work, and then replace it. work, and then replace it. 排出空气包气囊更换air bladder replacing for discharge dampenerair bladder replacing for discharge dampenern n 确认系统中已经完全泄压。确认系统中已经完全泄压。Make sure there is no pressure in Make su

106、re there is no pressure in the systemthe systemn n 拆卸掉盖。拆卸掉盖。Disassemble the cover of dampener.Disassemble the cover of dampener.n n 取下气囊取下气囊 。take out the air bladder take out the air bladder n n 检查气囊是否损坏，消除引起损坏的因素。检查气囊是否损坏，消除引起损坏的因素。n nCheck whether the air bladder is damaged or not. Eliminate the

107、 Check whether the air bladder is damaged or not. Eliminate the damage factor. damage factor. n n 检查底塞的状况，各边缘必须光滑。检查底塞的状况，各边缘必须光滑。Check the bottom plug Check the bottom plug condition and the edge should be smooth.condition and the edge should be smooth.n n 装入新气囊装入新气囊 install the new air bladder ins

108、tall the new air bladder n n 装上盖，勿使气囊变形或受挤压。装上盖，勿使气囊变形或受挤压。Install the upper cover and Install the upper cover and make sure the air bladder is not distorted and extruded. make sure the air bladder is not distorted and extruded. n n 上紧螺母。上紧螺母。Screw down the boltsScrew down the boltsn n 进行充气。进行充气。Cha

109、rge it. Charge it. 排出空气包总成排出空气包总成discharger air dampener assemblydischarger air dampener assembly排出空气包充气n n 取下空气包压力表罩，旋转排气阀压帽约取下空气包压力表罩，旋转排气阀压帽约1/41/21/41/2周，以排放残余压力，周，以排放残余压力，使压力表的读数为零，取下排气阀压帽和堵头。使压力表的读数为零，取下排气阀压帽和堵头。n nTake off the dampener pressure gauge cover; turn the discharge valve Take off t

110、he dampener pressure gauge cover; turn the discharge valve cap 1/41/2 round to discharge the remnants pressure to make the cap 1/41/2 round to discharge the remnants pressure to make the reading of the pressure gauge is zero and then get rid of the discharge reading of the pressure gauge is zero and

111、 then get rid of the discharge valve cap and plug. valve cap and plug. n n 把软管连到氮气瓶阀和空气包排气阀接头上。把软管连到氮气瓶阀和空气包排气阀接头上。n nConnect the hose to the nitrogen bottle valve and dampener discharge Connect the hose to the nitrogen bottle valve and dampener discharge valves connector. valves connector. n n 打开空气

112、包截止阀。打开空气包截止阀。n nOpen the shutoff valve on dampener Open the shutoff valve on dampener n n 缓慢打开氮气瓶阀开关，用此阀调节流入空气包的气体。缓慢打开氮气瓶阀开关，用此阀调节流入空气包的气体。n nOpen the nitrogen bottle valve slowly and adjust the air going into the air Open the nitrogen bottle valve slowly and adjust the air going into the air blad

113、der by this valve.bladder by this valve.n n 当空气包压力表指示到所需之压力时，关闭气瓶阀。当空气包压力表指示到所需之压力时，关闭气瓶阀。n nWhen dampener get to the specified pressure, please close the nitrogen When dampener get to the specified pressure, please close the nitrogen bottle valve.bottle valve.n nn n关闭空气包截止阀。关闭空气包截止阀。Close the shuto

114、ff valve on Close the shutoff valve on dampener.dampener.n n取下软管，盖上压力表罩，再次装上排气阀压帽和堵取下软管，盖上压力表罩，再次装上排气阀压帽和堵头。头。n nTake out the hose and cover the pressure gauge cover, Take out the hose and cover the pressure gauge cover, then install the discharge valve cap and plug. then install the discharge valve

115、 cap and plug. n n为了得到最好的效果，空气包预充压力不得超过泵的排出为了得到最好的效果，空气包预充压力不得超过泵的排出压力的压力的2/32/3，最大充气压力为，最大充气压力为4.5MPa4.5MPa（650psi650psi）。）。 n nTo get a better effect, the pre-charge pressure of the To get a better effect, the pre-charge pressure of the dampener should not higher than the 2/3 of discharge dampener

116、 should not higher than the 2/3 of discharge pressure. The Max. charge pressure is 4.5MPapressure. The Max. charge pressure is 4.5MPa（650psi650psi）。）。空气包充气注意事项 dampener charging instruction n n仅能使用压缩氮气或压缩空气，不能使用氧气、氢气仅能使用压缩氮气或压缩空气，不能使用氧气、氢气等易燃、易爆气体。等易燃、易爆气体。n nThe charge air shall be compressed nitro

117、gen or The charge air shall be compressed nitrogen or compressed air, not oxygen, hydrogen or some other compressed air, not oxygen, hydrogen or some other flammable and explosive gasesflammable and explosive gasesn n在保养空气包时，空气包内的气压必须为零，此时，在保养空气包时，空气包内的气压必须为零，此时，泵的压力也必须为零，不能完全依靠观察压力表的读数来泵的压力也必须为零，不能

118、完全依靠观察压力表的读数来判断，必须打开排气阀的压帽泄压，因残余压力较小时，判断，必须打开排气阀的压帽泄压，因残余压力较小时，压力表已无法显示，但此低压也可能导致事故的发生。压力表已无法显示，但此低压也可能导致事故的发生。n nWhen maintain the dampener, the pressure in it shall be When maintain the dampener, the pressure in it shall be zero. And so does the pump pressure. It should not zero. And so does the p

119、ump pressure. It should not judge the pressure through the reading of the pressure judge the pressure through the reading of the pressure gauge. Because when the pressure is low, the pressure gauge. Because when the pressure is low, the pressure gauge can not show. So it should open the discharge gauge can not show. So it should open the discharge valve to discharge the pressure, because such low valve to discharge the pressure, because such low pressure may still lead to accident. pressure may still lead to accident.