The valve body is constructed of high - strength alloy steel, which provides excellent resistance to high - pressure hydraulic forces and mechanical vibrations. The internal passages of the valve body are precisely machined to ensure smooth fluid flow and minimal pressure loss. The exterior is designed to be durable and may have a corrosion - resistant coating to withstand the harsh operating environments of the excavators.
（Spool and Sealing Materials）
The spool of the relief valve is usually made of hardened steel for precise movement and long - term durability. The sealing materials, such as high - quality rubber seals (e.g., nitrile rubber), are used to prevent hydraulic fluid leakage. These seals are designed to maintain their integrity over a wide range of pressures and temperatures.
