Valve

A control valve is often considered the “hands and feet” of a process control system. Whether a plant can maintain stable pressure, temperature, flow, or liquid level depends heavily on whether the control valve operates correctly. When a control valve fails, many engineers immediately think about removing and disassembling the valve. However, in most cases, […]

Introduction Valve pressure drop is one of the most important parameters in valve selection and piping system design. Many engineers have a common misunderstanding: “A higher upstream pressure means a higher valve pressure drop.” This statement is not always correct. Valve pressure drop is not determined by upstream pressure alone. The actual pressure loss across

When Alarms Are Not Enough In many industrial incidents, the real danger is not the alarm itself — but what happens after the alarm. Pipelines rupture, yet media continues to leak.Fires break out, but fuel supply is not isolated.Gas detectors trigger alarms, yet gas flow is not stopped. In these situations, risk escalates rapidly. Fire,

Valve packing leakage is one of the most common problems encountered during plant maintenance and field inspection. Gate valves leak, globe valves leak, and even control valves eventually develop packing problems. In many industrial systems, leakage around the valve stem is almost unavoidable after long-term operation. So what exactly causes valve packing leakage? Can it

In industrial process plants, one of the most frequently overlooked yet critical decisions in control valve selection is the fail action setting. For the same pneumatic control valve, some engineers prefer FC (Fail Close), others insist on FO (Fail Open), while some believe FL (Fail Locked) is the safest option. When asked why, the most

1. Comparison of the Performance Advantages and Disadvantages of the Top Ten Types of Control Valves Control valves can be categorized into ten main types. How do the nine key functional aspects compare across these types? To streamline the information, the following table summarizes the performance scores for the common types of control valves based

When there is a significant deviation between the actual valve position and the DCS (Distributed Control System) display (i.e., the actual valve opening differs considerably from the DCS screen reading), process control can be affected. To resolve this, a systematic approach must be taken to investigate signal transmission, positioner calibration, actuator functionality, and DCS settings.

When using a differential pressure flowmeter to measure steam, where exactly should the shut-off valve on the pressure tap be installed — before or after the condensation tank? According to some literature, it should be installed after the condensation tank. However, in practice, most installations place it before the tank. Which of these is correct?

This seemingly simple question has caused confusion for many companies and designers. Some choose to install cut-off valves, while others don’t, with practices varying widely. But what do the standards say? Are there clear requirements in the regulations? In this article, we will clarify the principles for the installation of cut-off valves in safety valve

A Common Engineering Misunderstanding in Atmospheric and Low-Pressure Storage Tanks In the petroleum, chemical, energy, and pharmaceutical industries, atmospheric and low-pressure storage tanks are among the most widely used process equipment.Unlike pressure vessels, the safety of these tanks does not rely on shell strength, but instead depends heavily on the effectiveness of their venting systems.