How to inspect threaded flanges, what are the steps?

How to inspect threaded flanges, what are the steps?

Today, Mr. Cui, the quality inspector of Qingdao fluido, inspected the American standard ASME B16.5 2-1/2" threaded flange and show you the steps.

1. Weight inspection

Use the weighing instrument to inspect the flange's weight and compare it with the standard. Weight deviation may be caused by unqualified wall thickness, size or material, which may cause quality problems of the flange, so this method can quickly check the quality of the flange.

The unit weight of the 2-1/2" threaded flange in the B16.5 standard is 3.52kgs(download here), and the unit weight tested by the inspector is 3.57kgs, which meets the requirements.

2. Marking inspection

Inspect the flange by visual method and check it with the contract. The marking on the flange needs to be consistent with the customer's requirements to avoid misunderstandings or disputes.

As can be seen from the photo below, the flange marking is clear and meets the contract requirements.

3. Dimension inspection

Use the caliper or thickness gauge to inspect the outer diameter, inner diameter, wall thickness and center distance of the flange, and confirm that it meets the requirements of the standard or customer drawings by comparing with the standard. This step is the key to ensure that the flange size is qualified.

The dimensions of 2-1/2" threaded flanges in the B16.5 standard are as follows. The flange dimensions tested by the inspector are all within the standard range.

4. Material detection

Use the handheld spectrometer to detect the flange material, and check whether the heat number corresponds to the original MTR to ensure that the flange material meets the requirements.

The quality inspector's inspection shows material is SS304 which meet the contract need. 

The last step is to use thread gauge to detect the flanges' threads. The most commonly used thread types are NPT, BSP, ISO, R or G. The quality of the thread directly affects the installation and sealing effect of the flange. There should be no burrs, paint or zinc slag on the thread. The quality inspector checks that the flange meets the NPT thread requirements.

Through the above steps of inspection, we can ensure that the quality of the threaded flange meets the requirements. I hope the above content will help you understand. If you have any comments or needs on the threaded flange, please feel free to contact Qingdao Fluido and we will give you the fastest reply. Thank you for your reading!

Qingdao Fluido flange catalogue download