Why is the flange of this level gauge thin and small?
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This post was last edited by liu530014416 on 2023-3-2 at 14:33. Dear teachers, a magnetic flap level gauge with a DN80 flange is nearly half as thin as the flange of the equipment, and it is also smaller in size. Does such a flange comply with the **regulations? Do manufacturers do this to save costs, or is **such a flange specified in the standards?**
Since the level gauge only requires a sensor to detect the liquid level, the size of the flange can be reduced, thereby lowering installation costs. -
The flange of the level gauge is manufactured as a custom flange; it is suitable for use at atmospheric pressure, but if pressure is involved, it must be of the same specification as the equipment’s connections.
This flange is likely only PN6; it depends on the operating conditions of the equipment. Secondly, the carbon steel bolts on site need to be replaced with stainless steel bolts.
For national standards, the thicker versions are in accordance with the standards set by the Ministry of Chemical Industry, and the requirements are different.
Generally, when ordering a level gauge, the technical parameters and standards for the connection flanges are required; it is necessary to check whether they meet the standards specified in the data sheet. The petrochemical plant failed to meet two safety standards on site: the flanges did not have the correct size and thickness, and the connection bolts were too long.
What the hell are these comments? The thicker ones meet the standards of the HG department, while the thinner ones either conform to the standards of the Machinery Department or national standards. Their characteristic is their thinness. When purchasing valves, if the standards set by the Chemical Industry Department are not specified, valves that meet the Machinery Department’s standards will be supplied; the dimensions and positions of the bolt holes are fine as well. The advantage is that they are cheaper, helping to reduce costs. What about non-standard flanges?
For example, for flanges with DN100 and CL300 specifications, both the SH and HG types have a thickness of 30.2, and a center hole diameter of 200. Flanges that follow mechanical standards have a thickness of only 24, with a center diameter of 190; different standards result in different thicknesses. Looking at the bolts at the bottom of the last image, they are all tilted; it seems that the level gauge and the pipe flanges do not match properly. Why are carbon steel bolts used with stainless steel flanges? Moreover, the length of the bolts is incorrect; it seems that the work wasn’t carried out according to the drawings. ;P
Must stainless steel flanges be paired with stainless steel bolts?