Gasoline tank truck unloading

It should be 1. The reference oil should be indicated by an initial made of two letters.

With money to spare, why use two pumps for unloading? P

The OP’s question is very common, as well as a classic and excellent one. In the design of oil depots, for non-liquefiable hydrocarbons and liquids that are difficult to vaporize, there is an issue of tank cleaning after unloading. In my opinion, there are two common methods: 1) a main pump plus a small tank cleaning pump. I’ve never used it, but it’s said to be very difficult to clean thoroughly as well. 2. Zero-position tank. First, it flows by gravity into the zero-position tank, and then it is pumped out; I’ve seen this method used, and it’s said to result in better drainage. In addition, some manufacturers have produced unloading pumps that come with a small tank; it is said that these pumps perform well in terms of unloading, and they are used in the oil depots of the CNPC system. If what I said is incorrect, please feel free to point it out. I hope those with experience can share their insights based on their own design and usage experiences, so as to provide useful references for others. Many hands make light work.

When we empty the tanks, a pneumatic diaphragm pump is used at the bottom of the tank.

Are there any specific recommendations for bilge pumps? Is a gear pump or a vane pump better?

Centrifugal pumps tend to run dry over time; if you need to pump to the bottom, consider using a diaphragm pump, as it should meet your requirements. Sliding vane pumps also fail to pump out all the liquid completely in the end.

This post was last edited by nan@ming on 2015-7-27 at 14:37. When we designed the jetty for unloading oil tankers, we used a centrifugal pump + water ring vacuum pump, and the results were good. Some owners do not want vacuum pumps; we have designed a combination of centrifugal pumps and swing rotor pumps, which also works well – it performs well even in Tibet, and its performance is better than that of German positive displacement pumps. However, domestically produced swing rotor pumps generate a lot of vibration. Using a centrifugal pump + sliding vane pump gives slightly poorer results, but it can still meet the requirements for lifting the pump and cleaning the tank. However, the sliding plate needs to be replaced after handling about 500–700 tank trucks. Oil is delivered by road transport and then unloaded; we usually pump it into the zero-level tank. If pumping is too slow after all the oil has been drained to zero level, use a centrifugal pump to drain the oil from multiple vehicles at once; after the remaining oil is placed in the zero-level tank, transfer it to the main storage tank. The method mentioned above involves using a small-volume pump (diaphragm pump, rotary vane pump) to remove excess oil, which is also an option; however, the process is too complex. Yet such pumps can transport oil and gas together, yielding good results. A diaphragm pump will work as well, but it requires a compressed air source. It’s generally not feasible for ordinary companies to do this; some automobile manufacturers, such as Changan, use diaphragm pumps for unloading and transferring materials. The reason is twofold: they have an air supply available, and these pumps are explosion-proof.