Fixed chemical injector is an important accessory in high-pressure cleaning machines and is widely used in cleaning and disinfection operations. Its main function is to improve the cleaning effect by sucking in detergents, chemical liquids or disinfectants and mixing them with high-pressure water flow to form a strong cleaning or disinfection solution. This injector is usually installed at the outlet end of the pump and is equipped with a nozzle with a small aperture inside. Whenever the cleaning machine is connected to a chemical nozzle with a larger aperture, the aperture difference will produce a pressure difference, which will cause a siphon effect, trigger the opening of the one-way valve, and smoothly suck in detergents or other chemical liquids. After the detergent is evenly mixed with the water flow, it is sprayed out from the nozzle to form an efficient cleaning liquid to meet different work needs. The suction volume of the syringe is fixed, which avoids the trouble of manual adjustment, ensures the accurate use of detergents, and improves work efficiency. The main body of the fixed chemical injector is made of high-quality brass material, which has extremely strong corrosion resistance and can operate stably for a long time in harsh working environments.