In a valve rating, what does the letter L indicate?

The letter L in a valve rating indicates "Liquid other than water." This classification is essential in plumbing and piping systems where valves are utilized to control the flow of various fluids. By specifying "Liquid other than water," manufacturers provide essential information regarding the types of liquids for which the valve is appropriate. This can include a wide range of liquids that may have different chemical properties, temperatures, and pressures than water. Understanding valve ratings is crucial as it helps ensure that the correct type of valve is used for specific applications, preventing issues like leaks or material degradation.