Valve:The valve is composed of a valve head and a stem. The temperature of the valve head is very high (intake valve 570~670, exhaust valve 1050~1200), and it also bears the pressure of the gas, the force of the valve spring and the inertial force of the transmission component, its lubrication and cooling conditions are poor, and the valve must be It has certain strength, stiffness, heat resistance and wear resistance. The intake valve is generally made of alloy steel (chromium steel, nickel-chromium steel), and the exhaust valve is made of heat-resistant alloy (silicon-chromium steel). Sometimes in order to save heat-resistant alloy, the exhaust valve head is made of heat-resistant alloy, and the stem is made of chrome steel, and then the two are welded together.Changing a centralized system is time-consuming and expensive because all connections and cables must be pulled and re-routed to new locations. Likewise, changing a centralized system often requires troubleshooting to ensure new processes do not interfere with old ones. Decentralized systems operate independently of each other so changes can be easily made without endangering the rest of the system.