如何调试 How to debug orifice plate flowmeter
1. Connect the signal and power cables. 2. Open the inlet and outlet valves with the same opening degree. 3. Open the stainless steel three-valve balance valve, slowly open the valve at the high and low pressure end of the orifice plate, and close the stainless steel three-valve balance valve after the fluid passes through the flow meter. Orifice flowmeter installation pipeline conditions:
(1) The straight pipe section used to install the throttle should be smooth. If it is not smooth, the flow coefficient should be multiplied by the roughness correction factor. (2) The straight pipe sections before and after the throttle must be straight and there should be no visible bend . (3) In order to ensure that the fluid flow forms a fully developed turbulent velocity distribution 1D in front of the throttle, and to make this distribution into a uniform axisymmetric shape, so: ① The straight pipe section must be round, and The 2D range of the front part requires strict roundness and a certain roundness index. Specific measurement method: (A) OD, D / 2, D, 2D 4 vertical pipe sections in front of the throttle, measure at least 4 single diameters of the inner diameter of the pipe at a maximum equal angular distance, and take the average value D. 其最大偏差不得超过±2%② 节流件前后要求一段足够长的直管段，这段直管段和节流件前的局部阻力件形式有关和直径比β有关。 The difference between the single inner diameter single measured value and the average value must not exceed ± 0.3% (B) After the throttle, 8 single inner diameter single measured values are measured at the OD and 2D positions by the above method. Compare any single measured value with D, the hole The maximum deviation of the plate flowmeter must not exceed ± 2%. ② A long straight pipe section is required before and after the throttle. This straight pipe section is related to the form of the local resistance member in front of the throttle and the diameter ratio β. (4) The length of the straight pipe section between the first resistance member and the second resistance member on the upstream side of the throttle can be in the form of the second resistance member and β = 0.7 (regardless of the actual β value). 2 (5) When the upstream side of the throttle is an open space or a large container with a diameter ≥ 2D, the length of the straight pipe between the open space or the large container and the throttle shall not be less than 30D (15D). If there are other local resistance parts between the throttle and the open space or the large container, in addition to the minimum straight pipe length 1 that meets the requirements between the throttle and the local resistance parts, from the open space to the The total length of the straight pipe sections between the flow pieces must not be less than 30D (15D).
与差压变送器及流量积算仪安装和接线 Orifice flowmeter and differential pressure transmitter and flow totalizer installation and wiring
1. There are two F4 gaskets between the orifice plate flow meter and the three valve group (leakproof) 2. The differential pressure transmitter is installed on the three valve group (two gaskets are also required in the middle). There are two letters on the differential pressure transmitter, one is L and the other is H (L stands for low pressure, H stands for high pressure) 3. The two flanges on the orifice flowmeter have +, —, and the + flange is installed on the fluid The direction from which the-sign is the direction the fluid goes. Cannot be installed 4. The H end of the differential pressure transmitter is installed on the + side of the three valve group corresponding to the orifice plate, and the L end is corresponding to the-side of the orifice plate. (Cannot be installed in reverse) 5. Wiring: There are three terminals of the differential pressure transmitter when the back cover is opened: +,-, + in the order of the last + without wiring. Just pick the + and-on the left. Corresponds to 4, 5, 6, 6 of the flow totalizer's wiring terminals, and 6 of the flow totalizer is connected to + on the left-hand side of the differential pressure transmitter. The terminals 4 and 5 of the flow totalizer are connected to the terminals of the differential pressure transmitter—. 7. After all the signal cables are connected, connect the 220v power supply (otherwise the flow totalizer will be burned). It is best to have a straight pipe section of about 5 meters.