When the fluid filled with pipes flows through the throttling parts (orificles, nozzles, etc.) in the pipes, the fluid will form a local contraction at the throttling parts, so that the flow rate increases and the static pressure decreases, so that the pressure drop or pressure difference is produced before and after the throttling parts, the greater the flow of the medium flow, the greater the pressure difference generated before and after the throttling parts. Therefore, the fluid flow rate can be measured by measuring the differential pressure.
Basic installation requirements:
(1) The throttling device should be checked before installation whether the number and size of the throttling device meet the requirements of the pipeline installation position.
(2) The newly installed pipeline system must be installed after pipeline flushing.
(3) When installing the throttling device, pay attention to the direction, and the party with the "ten" number should be installed in the upstream direction.
(4) When the throttling device is installed in the pipeline, it should ensure the perpendicularity and concentricity of the pipeline axis. The error of perpendicularity shall not exceed ±10, and the difference of concentricity shall not exceed 0.0025D/0.1+2.3B4.
(5) The various sealing gaskets used during installation shall not protrude into the inner wall of the pipeline.
(6) The hole plate must be installed at a rate of density, no leakage is allowed, and pressure test should be carried out after installation.
(7) The pressure guide pipe should be installed vertically or inclined, and its inclination should not be less than 1:12. For fluids with higher viscosity, the inclination should also increase, and when the pressure signal transmission distance is greater than 3 meters, the pressure guide pipe should be tilted in sections, and a gas collector and a settler should be installed at each highest and lowest point respectively
(8) In order to avoid differential pressure signal transmission distortion, positive and negative pressure tubes should be laid as close as possible, and anti-freezing measures should also be taken in cold areas.
(9) During installation, attention should also be paid to the position of the pressure opening. When installed on the vertical pipe, the position of the pressure inlet can be selected on the plane of the pressure inlet device: When installed on the horizontal pipe, the position of the pressure inlet is shown in the figure. (Measuring medium picture 1 for liquid, picture 2 for gas)
(10) The minimum pipe section length of the upper and lower reaches of the throttling device: (L1 and L2 are multiples of D).
