The correct installation steps for vacuum pressure switches

The correct installation steps of the vacuum pressure switch are as follows:

Calibration switch: First, clean the vacuum pressure switch. Check if the switch is in good condition by touch and visual inspection, and determine whether it is a normally open node or a normally closed node. The calibration environment requires a temperature between 15 and 25℃ and a humidity maintained between 45% and 75%. The switch should be placed in the environment for two hours before the calibration can begin. When calibrating, tools such as a calibration bench, standard meter, adapter, multimeter, wrench, and screwdriver are needed to calculate the maximum allowable error of the switch. That is, first calculate the PSI value of the switch and multiply it by 6.895 to obtain the range. Then, multiply the range by the accuracy and divide by 100 to get the final result.

Confirm the installation location: The pressure tapping port should avoid being in areas where the pipeline bends, forks, or where the flow beam forms vortices to ensure the accuracy of the measurement. When there are protruding objects in the pipeline (such as temperature measurement components), the pressure tapping port should be placed in front of it to avoid interference. If it is necessary to take pressure near the regulating valve, the distance between the pressure taking port and the valve should be determined according to the flow direction of the medium to ensure the accuracy and stability of the measurement. For wide containers, the pressure tapping port should be located in an area with smooth fluid flow and no vortices to ensure that the selected process parameters are measured accurately. The instrument should be installed perpendicularly to the horizontal plane, and the distance between the installation point of the instrument and the measurement point should be as short as possible to avoid slow indication.

Connecting the conduit: The horizontal section of the connecting conduit should have a certain slope to facilitate the discharge of condensed liquid or gas and ensure the accuracy of the measurement. The inclination direction of the conduit should vary depending on the medium being measured. When the medium being measured is gas, the conduit should be tilted low towards the pressure tapping port. When the medium being measured is a liquid, the conduit should be inclined towards the pressure measuring instrument. At the upper and lower bends of the conduit, devices for discharging condensed liquid or venting should be installed according to the medium conditions to prevent the accumulation of condensed liquid or gas from affecting the measurement accuracy. If the measurement point of the instrument is not at the same horizontal position as the installation point of the instrument, the correction of additional height error also needs to be considered.

Fixed switch: Check the name of the switch to ensure it is connected in the right place. Confirm the normally open and normally closed nodes. Install the pressure controller in the water source pipeline. Pay attention to the specification of the pressure controller joint. Users can choose a conversion joint. When installing, tighten the connection of the switch very hard to prevent oil leakage.

Electrical connection: When installing, please ensure that the electrical connection of the pressure switch is tight and reliable to avoid poor contact causing short circuits or damage to the equipment. Wiring according to the steps in the product manual. For example, for some pressure switches, screws No. 1 and No. 3 should be connected to the live wire and neutral wire of the input power supply respectively. The motor of the water pump is single-phase, and the two wires should be connected to screws No. 2 and No. 4 respectively.

Debugging and testing: Connect the power supply, let the pressure of the controlled medium rise, observe and adjust to ensure that the set value of the pressure switch is consistent with the indication of the pressure gauge. If the switch has not acted when the pressure rises to the upper limit setting, then turn the pressure adjustment screw, fine-tune it to the switching action, and repeat the verification once again. Also, conduct the lower limit verification. The process is the same as above. Repeat the verification several times. During the debugging process, the data from the pressure gauge was taken as the standard reference.

Sealing inspection: Ensure sealing performance and there should be no leakage, especially for flammable and explosive gas media and toxic and harmful media.

Fix the adjusting screws: Use red paint to fix the pressure adjusting screw and the pressure difference adjusting screw on the top of the iron shell of the pressure switch.