La horizontal split case pumps are a popular choice in many plants because they are simple, reliable, and lightweight and compact in design. In recent decades, the use of مورد تقسیم pumps has increased in many applications, such as process applications, for four reasons:

1. Advances in centrifugal pump sealing technology

2. Modern knowledge and modeling of fluid mechanics and rotational dynamics

3. Advanced manufacturing methods to produce precise rotating parts and complex assemblies at reasonable costs

4.The ability to simplify control through the use of modern control technology, especially modern variable speed drives (VSDs)

In terms of reliability, the pump curve deserves more attention regardless of the nature of the application. During the selection process, plotting the operating point curve of the application can mean the difference between saving money and losing money.

Best Efficiency Point

The best efficiency point (BEP) is the point at which the پمپ اسپلیت کیس افقی is most stable. If the pump is operated away from the BEP point, it will not only lead to an increase in unbalanced loads - the loads usually peak at the pump dead center, but also (over long periods of operation) reduce the reliability of the pump and the life of its components.

The design of the pump usually determines its optimal operating range, but the pump should generally be operated within 80% to 109% of the BEP. This range is ideal but not practical, and most operators should determine an optimum operating range before selecting a pump.

The required net positive suction head pressure (NPSHR) usually limits the operating range of the pump in terms of BEP. When operating well above the BEP flow, the pressure drop in the suction passage and piping will drop significantly below the NPSHR. This pressure drop can cause cavitation and damage to pump parts.

As pump parts wear and age, new clearances develop. The pumped liquid begins to recirculate more frequently (internal backflow - pump salon note) than when the pump was new. Recirculation can have a detrimental effect on the efficiency of the pump.

Operators should check the pump performance curve for the entire operating profile. Pumps operating in closed loop or recovery service (with bypass systems – pump salon note) should be operated close to the BEP or within about 5% to 10% to the left of the BEP. In my experience, closed loop systems pay less attention to the pump performance curve.

In fact, some operators do not check the alternative operating points or recovery flow range on the pump curve. Recycling service flows can vary widely, which is why operators must find and evaluate all possible operating points on the pump curve.

Extreme Operating Points

In bulk transfer service, the horizontal split پمپ کیس transfers liquid from a container or tank with different liquid levels at the suction and discharge ports. The pump pumps liquid out at the suction port and fills the container or tank at the discharge port. Some bulk transfer services require the use of control valves, which can significantly change the differential pressure.

Pump head is constantly changing, but the rate of change can be high or low.

There are two extreme operating points in bulk transfer service, one at the highest head and the other at the lowest head. Some operators mistakenly match the pump's BEP to the operating point at the highest head and forget about the other head requirements.

The selected pump will operate to the right of the BEP, providing unreliable and less efficient performance. In addition, because the pump is sized to operate at the highest head near the BEP, the pump is sized larger than it actually needs to be.

Incorrect pump selection at the lowest head operating point will result in higher energy consumption, lower efficiency, more vibration, shorter seal and bearing life, and lower reliability. All of these factors can significantly increase initial and operating costs, including more frequent unplanned downtime.

Finding the middle point

The best horizontal split case pump selection for bulk transfer service depends on locating the duty point at the highest head to the left of the BEP or at the lowest head to the right of the BEP.

The resulting pump curve should include operating points that take into account other factors such as NPSHR. The pump should operate near the BEP, which is the middle point between the highest and lowest heads, most of the time.

In general, all duty points should be identified and pump operation evaluated for all possible duty points.

An important consideration is the pump's operating conditions, and when the pump's performance is slightly reduced, the pump operating point on the pump curve is estimated. For some pump applications, such as bulk transfer service, there is a large difference between the highest and lowest head points, and a variable speed centrifugal pu