Instrumentation

In the field of industrial automation, interlock logic diagrams act as the “safety brain” of a system—precisely controlling equipment startup/shutdown, alarm responses, and emergency shutdown sequences. They are directly tied to personnel safety and the stable operation of multimillion-dollar facilities. An improperly designed reset switch can render interlock protection ineffective. Even worse, a small error […]

1. Introduction In process control systems, it is common to encounter situations where the effectiveness of one control loop depends on the status or mode of another. When this occurs, the loops are referred to as nested control loops. The most typical example is cascade control, but there are several other configurations, such as valve

In industrial environments, the integrity of instrumentation cable trays is essential for ensuring the safety and stability of control systems. A common but often overlooked safety hazard is the falling off of cable tray covers. This issue can lead to potential injury, equipment damage, or service disruptions. This article analyzes the main causes of cable

1. Overview of Push Buttons A push button is a type of manual control switch that is actuated by applying pressure using a part of the human body—typically the finger or palm. Equipped with a built-in spring mechanism for resetting, it is one of the most commonly used control devices in industrial and electrical systems.

Background In a 120,000 tons-per-year polyvinyl chloride (PVC) production facility, a critical incident occurred during the commissioning of newly installed valves on a liquid chlorine storage tank. The sudden shutdown was triggered by a tripped power supply circuit, which resulted in a full-scale plant stoppage and elevated the risk of hazardous chemical leakage. The root

Introduction In petrochemical production, automation instruments are the nervous system of the process. They play a critical role in ensuring operational stability, safety, and efficiency. Failures or inaccuracies in these instruments can lead to production losses or even severe safety hazards. This article presents a comprehensive methodology for troubleshooting typical issues in temperature, flow, pressure,

Introduction A Safety Instrumented System (SIS) is an independent system designed to prevent or mitigate hazardous events by automatically taking actions to bring a process to a safe state. Given the high risks associated with Level 1 Major Hazard Sources, determining whether an SIS is necessary requires careful evaluation of regulatory requirements, risk assessment results,

In industrial process control, accurate and reliable level measurement is essential for safety, efficiency, and automation. Among various types of level instruments, single-flange and double-flange differential pressure level transmitters are two commonly used solutions in industries such as petrochemical, pharmaceutical, and power generation. This article presents a detailed comparison of these two types of transmitters,

1. What Is an Electrical Schematic Diagram? An electrical schematic diagram (also known as a wiring diagram or circuit diagram) is a visual representation of an electrical system. It illustrates how various electrical components are connected and how current flows through the system. These diagrams serve as the foundational reference for electrical design, installation, commissioning,

1. Fundamental Differences 1.1 Function and Role Category Surge Protective Device (SPD) Lightning Terminal Core Function Limits transient overvoltages (such as lightning surges or switching transients) on power or signal lines. Ensures reliable electrical connection between lightning arrestors and grounding system to discharge lightning current safely. Target Directly protects electronic equipment or control systems from