Flanges are common components in pipeline engineering. In pipeline construction, flanges are primarily used to connect pipes. A flange plate is installed on each pipe to be connected. Low-pressure pipes use threaded flanges, while pipes with pressures above 4 kg use welded flanges. Low-pressure pipes with small diameters have threaded flanges, while pipes with large diameters for both high and low pressures use welded flanges. The thickness of flange plates, the diameter of connecting bolts, and the number of bolts required for each pressure range vary. Flanges are used in pairs. So, should flanges be stored directly after purchase? Or should we take steps before storage? With these two questions in mind, Hebei Ransheng Pipeline Manufacturing Co., Ltd., based on years of experience, will share some precautions before storing flanges.
Flanges should not be stored for long periods of time and should be inspected regularly. Frequently exposed machined surfaces must be kept clean and free of dirt. They must be neatly stored indoors in a well-ventilated, dry area. Stacking or outdoor storage is strictly prohibited. When using flanged ball valves, globe valves, and gate valves, they should only be used in fully open or fully closed positions, not for flow control, to prevent erosion and accelerated wear of the sealing surfaces.
Flanges are readily available, simple to manufacture, low-cost, and widely used, but they lack rigidity and should not be used in chemical process piping systems involving supply and demand, flammability, explosiveness, or high vacuum requirements, or in highly hazardous environments.
Sealing surface types include flat and raised faces. Flanges are simple in structure, compact, lightweight, and offer a tight and reliable seal. They are widely used as the sealing surface material for ball valves. Plastic, with its excellent sealing properties, is also widely used in vacuum systems. Maintenance is easy, and ball valves have a simple structure. The sealing ring is generally removable, making it easy to disassemble and replace. When fully open or closed, the sealing surface between the ball and valve seat is isolated from the media.
So, what should be checked when inspecting flanges? ① Verify that the name, specifications, model, quantity, and material are consistent with the technical requirements of the order contract.
② Check that the exterior markings are clear and that the specification and material markings match the material certificate. The forged surface should be smooth and free of forging marks, cracks, or other issues.
③ Inspect the internal and external surfaces of the flange for damage, deformation, cracks, burrs, or rust.
④ Check that the flange sealing surface is intact and free of damage.
⑤ Check the flange's outer diameter and thickness. The sampling inspection rate for dimensions is 5-10%, but at least two pieces per model should be inspected.
That concludes the flange inspection process after purchase. I hope you've learned something useful. After all, only by regularly inspecting flanges can we address any issues we discover. For example, if a flange is rusted, we need to remove the rust to extend its service life and ensure proper operation.