Understand the common technical indicators of the shield pump to help select the type of work

The shielded pump is popular because of its small size, no leakage, low noise and long life. Many customers will consult us about the selection of the shielded pump. Today we share some selection experience.

The shielded pump does not use a mechanical seal. The stator rotor of the motor is sealed with a stainless steel sleeve to provide a leak-free function. The product uses a sliding bearing to achieve low noise.

Shielding pump is used in civil applications. It can be used in gas fireplaces, heating circulating water systems, heat pump air conditioning water circulation systems, tap water boosters, air conditioners and high-speed rail locomotive pumps. The shielded pumps are also used in petroleum and chemical industries, and aerospace rocket launches. , ships and nuclear power plants and other fields.

Before purchasing a shielded pump, the customer should master the method of judging the quality of the shielded pump and understand the technical specifications of the commonly used shielded pump.

The technical indicators of the shielded pump mainly have the following points:

N speed, this parameter is easy to understand, that is, the number of revolutions per unit time of the shield pump, generally expressed in revolutions per minute.

H head, an expression of effective energy, that is, the value of the energy of the pump pumping unit liquid medium from the pump inlet to the outlet.

Q flow, this parameter describes the liquid medium sent by the shield pump in unit time. Units can be cubic meters per second, cubic meters per hour, liters per second, and so on.

P power, the power of the shield pump is divided into input power and output power, and the power that the prime mover transmits to the pump shaft is called input power. Output power refers to the effective energy that the pumped medium obtains per unit of time. There is a difference between the input power and the output power, which represents the power loss. The ratio between output power and input power represents efficiency.

NPSH cavitation margin, this parameter is used to describe cavitation performance.

When choosing a shielded pump, we mainly look at the following three points:

First, the operating stability and noise figure of the shield pump. This parameter is mainly related to the quality of the shielded pump motor.

Second, the sealing performance of the shield pump, it can be said that this is the core factor to measure its quality. It is not only at room temperature to meet this requirement, but also to meet the requirements of work in high temperature, high pressure, high corrosion, high melting point environment.

Third, the installation and post-maintenance of the shielded pump, the simpler, the more convenient. Good structural design can greatly save the cost of post-installation, commissioning and maintenance.

Because the sliding bearing in the shield pump is lubricated by the medium conveyed by the pump, if it is not installed horizontally, it will easily lead to lack of liquid in the bearing, and the lubrication is insufficient, resulting in dry grinding damage of the bearing. If it is not installed horizontally, the pump will be shaken during operation and will not be stable. At the same time, due to improper installation, the gas generated in the pump can not be exhausted, which affects the cycle cooling of the motor, causing the temperature rise of the motor to be high.

Therefore, we want to install the shielded pump horizontally after the correct selection of the shielded pump, so as not to affect the normal work progress.