Pipeline centrifugal pumps are general-purpose equipment for conveying clear water and liquids with similar physical and chemical properties, widely used in industrial and urban water supply and drainage, high-rise building pressure boosting, fire-fighting systems, HVAC circulation and other fields [2]. According to the installation form can be divided into vertical and horizontal, according to the impeller structure is divided into closed, open and semi-open [1], the adaptable medium temperature range -20 â?? to 240 â?? [3], typical models include ISG, ISW, IRG, etc. [2] [4].
The equipment consists of impeller, pump body, sealing ring and other core components, the impeller rotates to generate centrifugal force to achieve liquid transport, the pump body plays a supporting role, and the sealing system to protect the operating vacuum. It adopts modular piping design, equipped with high-efficiency hydraulic model, supports electric drive and direct connection structure, featuring low noise, small footprint and easy maintenance. Installation requires precise calculation of suction height and ensuring pipeline sealing, and the performance curve reflects the relationship between flow rate, head and power [4]. Common faults such as air binding can be solved by filling water and exhausting air, and the bearings and sealing parts need to be overhauled regularly [2].
Diaphragm pumps are designed to protect columns and cylinders by separating the liquid being pumped from the columns and cylinders with the aid of a membrane. The left side of the diaphragm in contact with the liquid are made of corrosion-resistant materials or coated with a layer of corrosion-resistant substances; the right side of the diaphragm is filled with water or oil.
Diaphragm pumps, also known as control pumps, is the main type of actuator, by accepting the control signal output from the regulator control unit, with the help of power operation to change the fluid flow. Diaphragm pump in the control process is to accept the regulator or computer control signals, change the flow of the regulated medium, so that the regulated parameters are maintained in the required range, so as to achieve the automation of the production process. If the automatic adjustment system compared with the artificial adjustment process, the detection unit is the human eye, regulation and control unit is the human brain, then the implementation of the unit - diaphragm pump is the human hand and foot. To achieve the process of a parameter such as temperature, pressure, flow, level and other regulatory control, are inseparable from the diaphragm pump.
Air operated diaphragm pumps are commonly used in five materials: plastic, aluminium alloy, cast iron, stainless steel, Teflon. Electric diaphragm pumps have four materials: plastic, aluminium alloy, cast iron, stainless steel. Diaphragm pump diaphragm according to different liquid media were used nitrile rubber, neoprene, fluorine rubber, PTFE, PTFE, etc. placed in a variety of special occasions, used to pump a variety of media to meet the needs. [2].
