Assembly of Petrochemical Gear Oil Pump and Problems in Pipeline Construction

≪ One> Assembly of gear oil pump

1. Key points for assembly of gear oil pump

During assembly, the pump body and stainless steel pump cover should be intact and not disordered. The main and passive gears should be of equal height, with a height difference of no more than 0.03mm; When pressing the driving gear shaft into the driving gear, the hot pressing method should be used. The driving gear should be uniformly heated to 150 ℃~200 ℃ before pressing in; The passive gear shaft is pressed into the gear oil pump housing. The value of the shaft head penetrating into the separated surface of the shell should comply with the regulations; After pressing the corresponding bushings into the passive gear, pump housing, and rear cover, the bushings should not protrude from the two ends of the gear, the end face of the pump cover, and the bottom plane of the pump body cavity; After the gear pair is installed in the housing, the end face clearance, tooth tip to pump clearance, and tooth side clearance should meet the technical requirements; The assembled gear oil pump should operate flexibly without any jamming phenomenon. The pressure limiting valve should be able to move flexibly inside the valve body, and can seat freely by its own weight, with a tight seal; The oil collection filter screen should be intact. If there is any damage, it is allowed to use soldering to plug it, but the soldering area should not exceed 10% of the filter screen area

2. Assembly of rotary gear oil pump

When installing the outer rotor of a rotary gear oil pump, the chamfered side of the outer rotor end face should be first installed in the housing, and then the inner rotor should be rotated to check for flexibility

3. Breakin test

The installed gear oil pump should undergo a running in test on the gear oil pump test bench. When running in, first run at the rated speed without load for 4 minutes, then gradually increase the load to the standard pressure for 3 minutes. There should be no noise, overheating, or oil leakage during the running in. After running in, check whether the repaired gear oil pump meets the specified performance indicators

< II A Brief Discussion on the Problems in the Construction of Gear Oil Pump Oil Pipelines The main medium used for transportation in oil gear oil pump pipelines is various raw material based products produced after petroleum cracking and processing. Many chemical media inside oil pipelines are toxic, and many products are flammable and explosive. Due to the complexity and instability of oil pipeline installation engineering, it is easily affected by the construction environment, construction materials, and actual engineering conditions. Therefore, in the installation and construction process of oil pipelines, it is necessary to strictly control the installation quality of various types of pipelines, otherwise it is easy to cause various accidents

1. Design problem of gear oil pump pipeline line

Due to some owners not needing the design institute to directly provide pipeline axonometric drawings in order to save investment costs.

. Often in the form of commissioning construction units or manually drawing single line diagrams; Due to the high pressure of project schedule, the detailed design time is tight, and the tasks are also heavy. In addition, the multiple upgrades of simple drawings have brought many troubles to pipeline construction

2. Lack of Technical Strength

In recent years, some large oil and engineering companies have continuously entered the Chinese market, and the demand for talent is increasing, and the treatment is also relatively generous. Therefore, the talent loss of domestic oil construction companies is relatively serious, and there is a growing shortage of technical personnel.

. Many construction projects require technical personnel to develop reasonable construction plans based on design requirements, engineering characteristics, and actual on-site conditions before construction, and they cannot provide sufficient technical disclosure to the construction team, which can easily lay quality risks for the construction of gear oil pump pipelines. Some construction units use welding personnel without welding project qualification certificates during the construction process of gear pump pipelines, which leads to welding quality problems

3. Low awareness of quality management in construction units

Due to the lack of technical personnel in some construction units, coupled with weak awareness of quality management, it is not possible to fully adopt traditional pipeline construction techniques and management concepts, such as the management of single line diagrams, installation and welding technology during the construction process. Traditional management models have always been used, resulting in a significant gap in management level compared to modern pipeline construction requirements.

There are many types of pipeline materials used in the construction site of petroleum gear pump pipelines. If the material quality management is not in place, it is easy to cause various quality hazards. The material management at some construction sites has the problem of untimely transplantation of color codes or labels for pipes and fittings, and the phenomenon of material mixing on site is quite serious. These problems have a significant impact on the quality of pipeline construction; During welding construction, there are many types of welding materials on some construction sites, and the management of baking, distribution, and recycling of welding materials is not in place. The follow-up management cannot be carried out, and the remaining welding materials cannot be recycled in a timely manner or dried according to regulations. There are also problems with non-standard use of welding rod barrels, which directly affect the welding quality of pipelines

4. Loose construction technology management

In oil pipeline construction, there are problems such as unclear welding technology disclosure or lax implementation of welding process instructions, which can easily lead to uncontrolled welding process parameters.

. During the construction process, some construction workers arbitrarily change the size or form of the groove, change parameters such as current and voltage, and some workers increase the welding speed in order to catch up with the work, resulting in various welding quality problems such as cracks, undercuts, porosity, and slag inclusion in the weld seam

5. Incomplete quality inspection

The installation and construction of gear oil pump pipelines require outdoor operations, and the construction sites are relatively scattered. Some technical, quality management, and non-destructive testing personnel cannot be fully equipped, the proportion of control inspections is insufficient, it is difficult to find non-destructive testing welds, the testing technology is lagging behind, and the repair process is not formulated in a timely manner, all of which will have a significant impact on the quality of pipeline construction.