What technical requirements must be met when installing a standard throttle device?

The main points are: the flow direction is correct, the straight pipe sections meet the requirements, the location of the pressure tapping points is appropriate, and the installation of the pressure guide pipes complies with the specifications.

1. The installation of the throttling element in the pipeline must ensure that it is perpendicular to the pipeline axis, with a deviation not exceeding ±1°. 2. The installation of the throttling element in the pipeline should ensure it is concentric with the pipeline. 3. The gaskets used to clamp the throttling element (including those between the ring chamber and the flange, between the ring chamber and the throttling element, and between the flange used for pressure measurement and the orifice plate) must not protrude into the inner wall of the pipeline after clamping. 4. To accurately determine the values at operating temperature, the measurement tube and throttle elements should be made of materials with known coefficients of thermal expansion. If the coefficients of thermal expansion of the materials used for the measurement tube and the throttle elements differ, the throttle element must be installed in such a way that it can expand freely when heated after being clamped, thereby avoiding deformation. 5. The connection between the flange of the throttle element (ring chamber or clamping ring) and the pipeline shall comply with the provisions of paragraphs 1 and 2. The pipe end and the flange sealing surface should be aligned. The flange sealing surface of the ring chamber or clamping ring should be convex and fit into the groove of the ring chamber or clamping ring. If the coefficient of thermal expansion of the material of the ring chamber or clamping ring is greater than that of the flange material, an interference fit should be used; otherwise, a clearance fit should be employed. 6. In applications where high measurement accuracy is required, to meet the above installation requirements, the throttle element, ring chamber (or clamping ring), along with the measurement tube over a length of 10D on the upstream side and 5D on the downstream side, should be assembled first. Only after passing inspection should they be connected to the main pipeline. 7. In newly installed pipeline systems, the throttle element must be installed after the pipeline has been flushed and cleaned. 8. There should be no sudden changes in pipe diameter at any connections between the various pipe sections and fittings of the throttling device