Application of Gear Pump in Special Situations and Pipeline Design Factors

1、 The application of gear pumps in certain situations: As viscosity increases, centrifugal pumps become inefficient, and users need to consider using positive displacement pumps (PD pumps, also known as positive displacement pumps). When the pressure needs to increase, some positive displacement pumps are difficult to sustain. When the temperature rises, other pumps will also fail

The gear oil pump has two meshing gear shafts of the same size. The drive shaft is connected to the motor or reducer (through an elastic coupling) and drives another shaft. In heavy-duty industrial gear pumps, the gears are usually integrated with the shaft (as a component), and the tolerance of the shaft neck is very small

There are three commonly used gear forms: straight teeth, helical teeth, and herringbone teeth. These three forms each have their own advantages and disadvantages, and have different applications

Straight teeth are a simple form and are preferred for use under high-pressure conditions, as they do not have axial thrust and have higher conveying efficiency. The helical teeth have less pulsation during the conveying process and are quieter at higher speeds because the meshing of the teeth is gradual. However, due to the effect of axial thrust, the selection of bearing materials may result in limited inlet and outlet pressure differences and lower processing viscosity. Because axial force will push the gear towards the bearing end face and cause friction, only by selecting a bearing material with higher hardness or designing on its end face can we cope with this axial thrust

The operating principle of an external gear pump is very simple. The liquid enters the suction end of the pump, is sucked in by the unmeshed interdental cavity, and then driven inside the interdental cavity to reach the outlet end along the outer edge of the gear shaft. The re meshing teeth push the liquid out of the cavity and into the back pressure area

2. Factors to Consider in Petroleum Pipeline Design

In the process of petroleum pipeline design, factors should be considered first, because problems are of utmost importance in the design of stainless steel pump pipelines. The following issues should be noted during the design process:

(1) Cut off valves should be installed at the boundary of the equipment for pipelines entering and exiting the device, and "8" shaped blind plates should be installed on the device side.

. There are many misconceptions in pipeline design nowadays, such as the use of "8-shaped" blind plates in transporting toxic pipelines, resulting in some pipelines entering and exiting the device lacking corresponding protection. However, if there is a lack of "8-shaped" blind plates, once personnel make mistakes or violate regulations, it will also pose a threat to people, such as suffocation, etc. So in the design process, attention should be paid to the design and planning of the "8" shaped blind plate of the device, which can reduce errors in actual operation and minimize losses to the design

(2) In the process of pipeline design, we should pay sufficient attention to pipelines that need to transport gases that are prone to hidden dangers or pose a threat to the environment. In locations with high accident rates, alarm devices should be designed. Once a danger occurs, an alarm will be issued immediately to remind workers to carry out timely maintenance

In the pipeline design process, inlet shut-off valves and bypass valves should be installed on the valves. During normal operation, the inlet shut-off valve should be locked in the open state, and the bypass valve should be locked in the closed state. In the design process, it should be noted that the drawings should be marked with symbols according to the following regulations:

L.O. or C S. O.=locked in open state (not allowed to close without approval)

L.C. or C S. C.=Locked in closed state (not allowed to open without approval)

When designing, these main signs are designed to make it easy for operators to learn and pay attention to these issues during operation