Valve Flow Calculation: Q = Cv x sqrt(dP/SG) Explained with Examples
The Short Answer Flow through a valve follows a simple square-root law for liquids: flow is proportional to the valve’s […]
Drawings & Calculations
Industry News
Smart Valve Technology Adoption: Diagnostics, Partial-Stroke Testing and Value
The Short Answer Smart valve technology — positioners and actuators with onboard sensors, diagnostics and digital communication — is being […]
Glossary
Valve Stem Types Explained: Rising, Non-Rising and Construction Variants
The Short Answer Valve stem types describe how the stem connects the operator to the closing member and how the […]
Valve Selection
How to Evaluate Chinese Valve Manufacturers: Certification, Traceability and Factory Audits
The Short Answer Evaluating a Chinese valve manufacturer comes down to four things: verifiable quality-system certification, complete material traceability, documented […]
Valve Standards & Specifications
China Valve Standards vs ASME/API: Dimensions, Ratings and What Buyers Must Check
The Short Answer Chinese valve standards (GB series) and international standards (ASME, API, ISO) cover similar products but differ in […]
Valve Selection
Importing Valves from China: Specification, Verification, Inspection and Shipping
The Short Answer Importing valves from China works well when the buyer manages four stages deliberately: specification, supplier verification, inspection […]
Valve Standards & Specifications
PN vs Class Valve Pressure Rating: What the Numbers Mean and How They Compare
The Short Answer PN and Class are two different ways of stating a valve’s pressure rating, and they are not […]
Valve Selection
Globe Valve vs Needle Valve for Regulation: Matching Scale to the Duty
The Short Answer Globe valves and needle valves both regulate flow by moving a disc or plug toward a seat, […]
Materials & Corrosion
PTFE vs PEEK Valve Seats: Temperature, Friction and Service Fit
The Short Answer PTFE and PEEK are both high-performance polymers used for valve seats and seals, and the choice usually […]
Troubleshooting & Maintenance
Valve Noise: Causes, Diagnosis and Fixes for Cavitation, Flashing and Vibration
The Short Answer Valve noise is a signal, not just a nuisance. The most common causes are cavitation, flashing, choked […]
Actuators
Rack and Pinion vs Scotch Yoke Actuator: Matching Torque to the Valve
The Short Answer Rack-and-pinion and scotch-yoke actuators are both pneumatic rotary actuators for quarter-turn valves, but they deliver torque differently. […]
Drawings & Calculations
Valve Cv Calculation: Formula, Worked Example and Sizing Steps
The Short Answer Cv, or flow coefficient, is a number that describes how much fluid a valve will pass at […]
Industry News
Electric Actuator Market Growth: Drivers, Limits and What Buyers Should Know
The Short Answer Electric valve actuators are the fastest-growing segment of the industrial valve actuation market, driven by plants replacing […]
Glossary
Fugitive Emissions Valve Meaning: Stem Seals, Standards and Compliance
The Short Answer Fugitive emissions are unintentional leaks of gas or volatile liquid from pressurized equipment — and for valves, […]
Valve Selection
Pinch Valve vs Gate Valve: Which Seals Better for Slurry and Abrasive Service?
The Short Answer Pinch valves and gate valves both act as on/off isolation devices, but they seal with completely different […]
Valve Standards & Specifications
ASME B16.5 vs B16.47 Flanges: Sizes, Series and How to Choose
The Short Answer ASME B16.5 and ASME B16.47 are two different flange standards that cover different size ranges. B16.5 is […]
Materials & Corrosion
EPDM vs Buna-N Valve Seats: Chemical Compatibility and Selection
The Short Answer EPDM and Buna-N (NBR) are both common elastomers for valve seats and seals, but they serve opposite […]
Troubleshooting & Maintenance
Control Valve Hunting: Causes, Diagnosis and Fixes
The Short Answer Control valve hunting is a rapid, continuous cycling of the valve and its positioner around a setpoint […]
Actuators
Air Lock vs Spring Return Actuator: Which Failure Mode Do You Need?
The Short Answer An air lock actuator and a spring return actuator are two ways of positioning a valve for […]
Drawings & Calculations
Valve Leakage Class Explained: Limits, Testing and How to Specify
The Short Answer Valve leakage class is a standardized way of expressing how much leakage a valve may pass when […]
Industry News
Valve Industry Automation Trends: Smart Positioners, Electric Actuation and Digitalization
The Short Answer The industrial valve market is moving decisively toward automation and digitalization. Smart positioners with diagnostics, predictive maintenance, […]
Glossary
Fire Safe Valve Meaning: What the Rating Really Covers
The Short Answer “Fire safe” describes a valve design that is tested and shown to limit leakage — seat and […]
Valve Selection
Check Valve vs Gate Valve for Isolation: Which One Stops Flow Properly?
The Short Answer Check valves and gate valves both live in industrial piping, but they are not interchangeable for isolation […]
Materials & Corrosion
Hastelloy C-276 vs Inconel 625 Valves: Material Differences Explained
The Short Answer Hastelloy C-276 and Inconel 625 are both nickel-based corrosion-resistant alloys used for valve bodies, trims and piping […]
Actuators
Limit Switch vs Valve Positioner: Two Accessories, Two Different Jobs
The Short Answer Limit switches and valve positioners are both mounted on actuated valves, but they do different jobs. A […]