The Valve Component

Introduction
A Valve element represents a component that will be inserted into the request processing pipeline for the associated Catalina container (Engine, Host, or Context). Individual Valves have distinct processing capabilities, and are described individually below.
The description below uses the variable name $CATALINA_HOME to refer to the directory into which you have installed Tomcat 5, and is the base directory against which most relative paths are resolved. However, if you have configured Tomcat 5 for multiple instances by setting a CATALINA_BASE directory, you should use $CATALINA_BASE instead of $CATALINA_HOME for each of these references.
Access Log Valve
Introduction
The Access Log Valve creates log files in the same format as those created by standard web servers. These logs can later be analyzed by standard log analysis tools to track page hit counts, user session activity, and so on. The files produces by this Valve are rolled over nightly at midnight. This Valve may be associated with any Catalina container (Context, Host, or Engine), and will record ALL requests processed by that container.

valve Role

Linear Motion traditional form, in accordance with its principles can be divided into : screw Movement (electric push rod and screw lifts); Hydraulic cylinder; Cylinder three categories। With modern technology processing the application, product performance continued to be refined, and more prominent electric push rod. Notable features are as follows :
Self-locking performance precision positioning • • • precise control synchronization • • Driver Overload Protection System can be equipped with safety clutch defense overload; can be equipped with pressure sensors set off anti-overload • • high load other simple maintenance, low noise, high / low temperature, anticorrosion / Ex bad normal work environment

Introduction of flameout protector

The purpose of flameout protector:

When we use the cook top, the fire may be extinct because of the wind or overflowing water. In this case, the protector may cut off gas to prevent some accidents happening because of its leakage, such as poisoning, explosion or fire. In this way, it realizes its safety protection function. Working sketch-map of flameout protectorThe first step: PiezoelectricityThe second step: Valve-open conditionThe third step: Cut off gas in sudden flameout condition