How to Reasonably Design the Inlet and Outlet Pipelines of Dalian Acid Resistant Pump

The interior of the pipeline connecting the acid resistant pump and equipment in Dalian should be cleaned thoroughly. Fixed welding joints should be kept away from equipment. No additional external force is allowed to be applied to the equipment. Temporary blind plates should be added to the inlet and outlet of the equipment, and can only be removed after the pipeline is blown clean. The flange spacing should be a small distance that allows the gasket to be smoothly inserted. When terminating the pipeline, a dial gauge should be used on the coupling to monitor its radial displacement. When the speed is ≤ 6000 rpm, the displacement is ≤ 0 05mm. When the speed is greater than 6000rpm, the displacement is ≤ 0.02mm. Otherwise, adjust the pipeline.

When there is a variable diameter pipe in the inlet pipe system of the acid resistant pump, an eccentric reducer with a diameter ≥ DN65 is used to prevent gas accumulation at the variable diameter location. The installation of the variable diameter pipe is shown as follows: when the front bend of the inlet flange is downward, the top of the variable diameter pipe is flat; When the bend is upward, the bottom of the variable diameter pipe is flat.

The suction inlet of the dual suction acid resistant pump should be equipped with a straight pipe section that is not less than 3 times the inlet diameter of the pump. Large pumps should have a straight pipe section that is 7 times or more the inlet diameter of the pump to ensure smooth liquid flow into the acid resistant pump, avoid bias and rotational flow, and prevent vibration and noise of the acid resistant pump.

When the piping of the dual suction acid resistant pump is upward suction, there is no need to consider the required straight pipe section on the suction inlet. Vertical pipelines can be directly connected to the suction pipe mouth through elbows and reducers, and are required to be as short as possible.

When the suction and discharge ports of the acid resistant pump are on the same vertical plane, in order to facilitate the installation of valves, eccentric reducers or two 45 ° elbows can be used to increase the distance between the inlet and outlet pipes:

The outlet pipeline of acid resistant pumps must have a certain degree of flexibility, especially under high temperature and high pressure conditions, and must undergo stress analysis to determine the geometric shape of the pipeline based on the magnitude of thermal stress.

The outlet of the acid resistant pump should not be directly connected to an elbow. Drain the shut-off valve and check valve between the acid resistant pump outlet with a drain valve. The acid resistant pump outlet pressure gauge is installed on the short joint between the acid resistant pump port and the check valve, and can also be installed on the outlet reducer. The pressure gauge connection should have a root valve, and the pressure gauge head should face the operating surface.

Protection pipeline of acid resistant pump - preheating wire: When the temperature of the medium conveyed by the preheating wire is greater than 200 ℃, in order to avoid the rapid influx of high-temperature liquid into the pump to be operated when switching acid resistant pumps Uneven heating of the acid resistant pump body and impeller can cause damage or deformation, resulting in jamming of the fixed and rotating parts. Therefore, a preheating wire needs to be installed to keep the stopped acid resistant pump in a waiting state for switching at any time.

Protection pipeline of acid resistant pump - small flow line: When the working flow rate of the pump is lower than 30% of the rated flow rate of the acid resistant pump, a force perpendicular to the axis direction - radial thrust will be generated. Moreover, due to the low efficiency of the acid resistant pump operation, the liquid temperature at the inlet increases, the vapor pressure increases, and cavitation is prone to occur. To prevent cavitation, a small flow line should be set up for the acid resistant pump to operate normally at the lowest flow rate.

The protection pipeline of acid resistant pump - balance line: For liquids that are in a bubble point state when transporting saturated vapor pressure and high dry atmospheric pressure at room temperature, in order to prevent steam or bubbles from entering the acid resistant pump and causing cavitation, a balance line is generally recommended. The balance line is connected from the inlet of the acid resistant pump to the gas phase section of the suction tank (tower).

Protection pipeline for acid resistant pump - bypass line: When starting a high head acid resistant pump, the outlet valve is subjected to excessive pressure on one side, making it difficult to open. If forced to open, there is a risk of damaging the valve stem and seat. By installing bypass lines with flow restriction orifice plates before and after the outlet valve, it can be easily opened. At the same time, the bypass line also has the function of reducing pipeline vibration and noise.