The function of the Ingersoll Rand screw air compressor temperature control valve is to regulate the exhaust temperature of the compressor head. Its working principle is based on thermal expansion and contraction: the temperature control valve core extends or contracts to adjust the oil passage formed between the valve body and the housing, thereby controlling the proportion of lubricating oil entering the oil cooler. This ensures that the rotor temperature remains within the set range. When the exhaust temperature of the compressor head is too low, moisture may separate out in the oil-gas tank, causing emulsification of the lubricating oil. During cold starts, the temperature control valve forces the lubricating oil to bypass the oil cooler and enter the compressor head directly. When the oil temperature rises to a fixed value, the temperature control valve opens the passage to the oil cooler, allowing the lubricating oil to be cooled before being injected into the compressor head. Since the lubricating oil entering the temperature control valve is unfiltered and the internal passages of the valve are complex, it is prone to debris accumulation. After prolonged use, the failure rate of the temperature control valve is relatively high, often triggering high-temperature protection in the machine. Additionally, once the temperature control valve opens the passage to the oil cooler, it cannot cut off the direct channel for hot oil to enter the compressor head. As a result, the temperature of the lubricating oil entering the compressor head is higher than the outlet temperature of the oil cooler, leading to reduced cooling efficiency. By inspecting the four oil pipes connected to the temperature control valve, one can determine whether the valve is functioning properly.