Flat washers are usually used to increase the contact area of screws and contact surfaces, disperse pressure and prevent fasteners from causing damage to the contact surfaces, and also have a certain anti-loosening effect. Nuts are a kind of fasteners, which are used in conjunction with bolts or screws to produce clamping force by tightening and connecting two or more parts. Flange fittings are a kind of parts used to connect pipelines, valves, pumps, and other equipment. Using bolts and nuts, the two flanges are fastened together to achieve connection and sealing, stainless steel sleeves may be used to protect internal parts from corrosion, abrasion, or external impacts while providing structural support, and stainless steel braided mesh may be used to enhance the structural strength of a product, to provide filtration, or to be used as a shielding layer, rubber inner tubing is typically used for the fluid transfer or as a sealing member, and provides good elasticity and sealing, and plastic insulating washers are primarily Plastic insulating gaskets are used to provide electrical insulation and sealing to prevent current leakage and media penetration.