What standards should be followed for the flanges of the ball receiving and sending cylinders?

I. Overview: The ball receiving (sending) cylinder is an important device used in oil and gas transportation pipelines for line cleaning and pigging; it plays a vital role in improving transportation capacity and ensuring safe production. The product structure and the selection of blind plates are directly related to the performance and safety of the product. 1. The ball receiving and sending cylinders come in standard specifications and structural designs; there is no fixed pattern, and various pipe connections can be added or removed as per the actual needs of the user. 2. When the design pressure of the flanges used for connection (all supplied as complete sets) is ≥ 4.0 MPa, butt-welded flanges should be selected; otherwise, slip-welded flanges shall be used. All the flanges used meet **the corresponding standards (JB82-59)**. If flanges are to be supplied, a 20% increase in the product price should be specified in the order contract. 3. Reinforcement diagrams shall be added whenever the outer diameter of all nozzles exceeds Φ57. 4. When the pipe diameter is ≥Φ114, the protrusion length is 200 mm; for all other pipes, the protrusion length is 100 mm. II. Technical Requirements 1. This equipment is manufactured, tested, inspected, and verified in accordance with the relevant provisions specified in GP150-98 \"Steel Pressure Vessels\". 2. Welds of category A and B in the vessels shall be subject to 50% radiographic inspection; the radiographic inspection of these welds is carried out in compliance with JB4730-94 \"Non-Destructive Testing of Pressure Vessels\". 3. All sealing surfaces shall be protected before leaving the factory to prevent damage. 4. After the equipment is manufactured, the outer surface should be thoroughly cleaned of rust and dirt, followed by applying a phenolic primer and then a topcoat.

Going back to what was said upstairs: “All the flanges used meet the **relevant standards (JB82-59)**” – this information comes from a manufacturer’s website, and the JB82-59 standard referenced there is already over half a century old