Orifice plate flowmeter installation method

Among the many fluid flow measuring instruments, the most common type of metering flow meter is the orifice meter. However, many users who use the orifice meter for the first time are still unfamiliar with its installation method. Give a brief introduction.

Installation of orifice plate flowmeter pipeline conditions and steps:

1. The straight section before and after the throttle must be straight and must not be bent by the naked eye.

2. 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.

3, in order to ensure the flow of fluid to form a fully developed turbulent velocity distribution at the 1D before the throttling, and to make this distribution into a uniform axial symmetry, so:

(1) The straight pipe section must be round, and the roundness of the throttling piece must be extremely strict with respect to the front 2D range of the throttling piece, and there must be a certain roundness index. Specific measurement methods:

A. At the front of OD, D/2, D, and 2D of the throttling piece, at least four pipe inner diameters are measured at a substantially equal angular distance on the four vertical pipe sections, and an average value D is taken. The difference between the single measured value and the average value of any internal diameter must not exceed ±0.3%

B. After the throttling device, the 8 internal diameters measured at the OD and 2D positions are measured by the above method. The maximum deviation of any single measured value from the D is not more than ±2%.

(2) A sufficiently long straight pipe section is required before and after the throttle piece. The long enough straight pipe piece and the local resistance piece form before the throttle piece are related to the diameter ratio β.

(3) The length of the straight pipe section between the first resistance piece and the second resistance piece on the upstream side of the throttle piece may take the value of the second resistance piece and β = 0.7 (regardless of the actual β value) 2.

4. When the upstream side of the throttle is an open space or a large container with a diameter ≥ 2D, the straight length between the open space or large container and the throttle must not be less than 30D (15D). If there is any other local resistance between the throttle and the open space or large container, except from the open space to the joint, the length of the minimum straight pipe section 1 is provided between the throttle and the local resistance. The total length of straight sections between flow elements must not be less than 30D (15D).

5. Connect the signal cable and power cable according to the flowmeter installation instructions.

6, open the import, export valve, import and export valve opening to be consistent.

7. Open the stainless steel three-valve bank balance valve, slowly open the high-low pressure side valve of the orifice plate, and close the stainless steel three-valve bank balance valve after the fluid passes the flowmeter.