A tank truck, gas truck, fuel truck, or Tanker Truck or tanker , is a motor vehicle designed to carry liquids or gases on roads. The largest such vehicles are similar to railroad tank Cars which are also designed to carry liquid loads. Many variants exist due to the wide variety of liquids that can be transported. Tank trucks tend to be large; they may be insulated or non-insulated; pressurized or non-pressurized; and designed for single or multiple loads (often by means of internal divisions in their tank). Some are semi-trailer trucks. They are difficult to drive and highly susceptible to rollover due to their high center of gravity, and potentially the free surface effect of liquids sloshing in a partially filled tank.
Tank trucks are described by their size or volume capacity. Large trucks typically have capacities ranging from 5,500 to 11,600 US gallons . In Australia, road trains up to four trailers in length (known as Quad tankers) carry loads in excess of 120,000 L. Longer road trains transporting liquids are also in use.
A tank truck is distinguished by its shape, usually a cylindrical tank upon the vehicle lying horizontally. Some less visible distinctions amongst tank trucks have to do with their intended use: compliance with human food regulations, refrigeration capability, acid resistance, pressurization capability, and more. The tanks themselves will almost always contain multiple compartments or baffles to prevent load movement destabilizing the vehicle.
Water Tanker Truck,Water Truck,Water Sprinkler,Tanker Truck,Sprinkler Truck,Tank Truck Zhengzhou Dongfeng Mid-south Enterprise Co., Ltd. , https://www.cn-dfmtruck.com
  
As an energy-saving and material-saving product , the application scope of screw pump in Jilin Chemical Fiber Group Company is expanding constantly. Especially, the double-screw pump has the advantages of no pulsation in liquid balance, long service life, strong self-absorption ability and external bearing structure In the long wire stock solution workshop production is also more and more widely. In the development of quality and reduce consumption has achieved good results. However, there are some problems in the course of the problem worth discussing.
  
The cause of the failure of the twin-screw pump is usually caused by many factors. Different faults show different phenomena. To eliminate the fault, the cause of the fault must be first identified. In practice, through the scientific research, prediction and analysis, it is found that the twin-screw Abnormal pump performance, which found problems, solve problems and eliminate faults. The general principle of judging the fault of twin-screw pump is to find out the reason by combining the structure, the principle of contact and clarifying the phenomenon.
  
After the long-term operation of the twin screw pump, an abnormal failure occurs, and the following problems usually occur.
  
1, the pump vibration or noise causes: the installation of the pump is not strong, the pump installed too high, more than the capacity of the pump; motor ball bearings damaged; pump spindle bending or eccentric spindle with the motor, not parallel, etc .; suction pipe or Pump suction side leakage; suction line blocked. The solution is to stabilize the pump or reduce the pump installation height, reduce the suction pipe resistance, cleaning or increase the filter to reduce the viscosity of the medium; replace the motor ball bearings; to correct the bending of the pump shaft or adjust the relative position of the pump and the motor ; Elimination of inhalation pipe and suction side of the pump leaks; Elimination of suction tube blockage.
  
2, drive shaft or motor bearing overheating reasons: the lack of oil or bearing rupture. The solution is to refill the oil or replace the bearing.
  
3, the pump heat: the pump rotating parts serious friction; mechanical seal back to the oil hole plugged; oil temperature is too high; installation is not correct, the rotating parts are not the heart. Solution is to check the replacement of wear parts; to clear the return hole; appropriate to reduce the oil temperature; adjust the calibration assembly and installation accuracy.
  
4, no flow output: the suction pipe blocked or leaks; inhalation height promised to inhale the vacuum height; electric reversal; media stick too much and other causes. The solution is to check the suction line, reduce the suction height, change the motor direction, heat the media and more.
  
5, the pump pressure is insufficient: the seal is leaked; stop the device state, when the screw pump there is no self-closing function, water inspection; selection is correct; outlet pressure is too large, and so on. Insufficient pressure on the pump. A lot of problems involved. The easiest is to check whether the import blockage. Look at the motor. If these two no problem, then you have to look at the screw and the bearing is not broken
  
6, the flow decline: suction pipe blockage or leakage; spiral sleeve, sleeve wear; safety valve spring is too loose or disc valve seat and lax contact; motor speed is not enough; the installation is too high, more than the ability to pump shaft seal leakage. The corresponding solution should be to repair the suction line; wear parts should be replaced when severe wear; adjust the spring, grinding disc and valve seat; repair or replace the motor; reduce the suction height and suction pipe resistance; repair or replacement of shaft seals .
  
7, a large number of mechanical seals oil spills: wrong assembly position; sealing gland is not flat; moving ring or static seal surface bump; moving ring or static ring seal damage. The solution is to re-install as required; adjust the gland; grind the sealing surface or replace the new one; and replace the sealing ring.
  
8, mechanical seal fever: sealing liquid pipeline blockage; mechanical seal spring compression is too large. The solution is to eliminate the sealing tube failure; reduce the amount of spring compression.
  
9, the shaft power increased dramatically: the discharge pipe plug; screw and pump sets of serious friction; medium viscosity is too large; installation is not correct, the rotation of parts are not the heart. The solution is to stop the pump cleaning pipeline; repair or replacement of parts; the media warming, reducing viscosity; adjust the calibration assembly and installation accuracy.
  
10, hold the shaft (can not rotate): excessive temperature pump over-expansion of parts; starting torque is not enough. The solution is to pump after the hand-cranked disk and then start; check the drive.
  
Twin screw pump operation, found the abnormal phenomenon, we must conduct a careful investigation, according to the phenomenon of failure, analysis and determine the location and cause of the fault. Sometimes a fault may have several anomalies, sometimes an anomaly, may have caused several failures. Therefore, the twin screw pump operation abnormal phenomenon, we must carefully find out the causes of abnormal phenomena, which requires us to be good at making analytical reasoning, through the phenomenon of grasping the substance, to identify the cause and location of the fault will be troubleshooting.
  
Screw pump applications and areas are more and more large, the more stringent technical requirements, it should be studied for different screw pump is the focus of future research. Twin screw pump market prospects are very broad. However, due to the reliability of twin-screw pump needs to be further strengthened, so to improve the technical content of twin-screw pump product is the main direction of development of screw pump manufacturers in the future.
Analysis and solution of double screw pump fault
   Screw pump is a positive displacement pump , screw pump was first introduced in the 20th century, 60 years of production, compared to the development of foreign screw pump technology nearly 20 years later, but with the continuous economic development, our country in-depth study of foreign advanced technology , Developed a twin screw pump, three screw pump, five screw pump. Due to its unique structure, self-priming capability, high efficiency, small size, reliable work, and can transport a wide range of viscosity media, screw pump is widely used in petrochemical, shipping, electric power, mechanical pressure system, food, paper, Sewage treatment and other industrial sectors.