But what if you want to retain the information stored in master table to เพิ่มยอดวิว analyze the job, KEEP_MASTER clause is used if we need to retain the master table even after a successful job or killed job. JOB_NAME – This is used to give a specific name to the export job, by default the job name is in the format SYS_EXPORT__NN. ESTIMATE – This is used to estimate how much space each table in the export job will consume (in bytes). And getting on the homepage led to 3,097 views in my video’s first week. Session Time (also known as “Session Watch Time”) is the total amount of time someone spends on YouTube after watching your video.

This article will help you identify the critical areas where extra attention must be paid to ensure a successful installation. Once you’ve been in the pump industry a while, reading a pump curve will be second nature. However, if you’ve never been taught how to read and understand a pump curve, it’s a skill you must master as quickly as possible.

This article will help you understand how to apply pumps in a variable speed application. The operation of this pump is based on the fluid being continuously pumped from a suction nozzle located at the center of the impeller. A horizontal pump delivers liquid at a very high speed by using a drive motor. It is designed in such a way that fluids with equal speed can exit the impeller and enter the pump.

Pumping

The NPSH curve is more relevant to rotary centrifugal pumps and less relevant to positive displacement pumps which are less likely to operate end of curve and cavitate. In the below curve an NPSH of 3.32M is required to deliver the required performance. A vertical turbine pump is commonly used in the water utility and industrial sectors to lift water from deep wells, reservoirs, or underground aquifers.

As the shaft speed or the impeller diameter is altered, the flow will change by the same amount. If the speed of a pump is reduced by 20% the flow at the same head will also decrease by 20%. This means that depending on the class used for testing the head can vary between +- 0% to +-7% and flow between 0% to +-9% which requires careful consideration during pump selection. Although a pump curve shows the various duty points that a pump can achieve, operating the pump in some of the areas of operation can lead to many problems. As 90% of problems with pumps are caused by the system they are installed in, it is important to note that pump selection is just part of the process of selecting a pump which is right for the process. Sulzer offers one of the most comprehensive ranges of submersible pumps available on the market today.

Detailed Pump View Widget

Special attention should be paid to the location of BEP relative to the operating condition. For this reason the Hydraulic Institute (HI) has defined a pumps Preferred Operating Region (POR) as flows from 70% to 120% of flow at BEP for most centrifugal pumps. Years ago, making a pump selection meant sitting down with large printed catalogs and flipping through them until you reached a pump curve that fit a project’s hydraulic requirements. Today this process is made much easier through the use of electronic pump curve catalogs. One of the most well-known developers of electronic pump catalogs is Engineered Software and their pump selection software pump-flo.

Its All About Databases & Their Performance, Troubleshooting & Much More … ¯\_(ツ)_/¯

Outside of Oracle Database, uou are not given direct access to those files, unless you have the appropriate operating system privileges. Similarly, Oracle Database requires permission from the operating system to read and write files in the directories. The following example shows a SQL statement that creates a directory object named dpump_dir1 that is mapped to a directory located at /usr/apps/datafiles. The usefulness of the estimate value for export operations depends on the type of estimation requested when the operation was initiated, and it is updated as required if exceeded by the actual transfer amount. In logging mode, real-time detailed status about the job is automatically displayed during job execution. In situations where there are conflicting table attributes, Oracle Data Pump is not able to load data into a table using either direct path or external tables.

The flow through a screw pump takes place axially and in the direction of the driver screw. Due to the movement of this gear, the idler (driven) gear also starts rotating. The cavity formed between the teeth of these gears is closed by the pump casing and the side plates (also known as wear plates or pressure plates). This pump produces the flow of fluid due to fluid flow between these two gears. In maximum cases, hydraulic pumps are used to energize the fluids from lower pressure to higher.

The water would then exit the second stage diffuser and flow up the pump column to the discharge point. Vertical inline pumps are commonly used in water and chemical pumping applications but are not typically used in solids-handling applications. [newline]They are very common in HVAC and plumbing applications and are growing in popularity in other applications. Specialty designs are often fitted with unique impeller designs allowing end-suction pumps to be used in solids-handling applications, such as pumping municipal and industrial wastewater. One particularly popular specialty end-suction design is the submersible pump. The submersible pump is an end-suction design that has been fitted with a motor designed to operate while submerged. This allows the entire pump to be submerged in the liquid being pumped.