1. Enabling detachable connectionsThis is the primary function of fasteners. Unlike permanent connections such as welding or riveting, connections made with fasteners—such as bolts, screws, and nuts—allow for disassembly, replacement, or maintenance without damaging the components. For example, auto

1. Basic Functions and Classification of ValvesValves primarily perform the following functions: shutting off or connecting the flow of media within a pipeline, regulating media flow rate and pressure, altering flow direction, and ensuring the safety of pipelines or equipment (e.g., safety valves, p

Weathering steel—fully known as "atmospheric corrosion-resistant steel"—is a type of low-alloy steel that falls between ordinary carbon steel and stainless steel. By adding small amounts of alloying elements such as copper, phosphorus, chromium, and nickel to ordinary carbon steel, a dense, protecti

H40 / J55 / K55 (Entry-level)These three grades belong to API 5CT Group 1; they share the same chemical composition requirements but differ primarily in mechanical properties. H40 has the lowest strength and is used for the shallowest, lowest-pressure wells. J55 and K55 share the same yield strength