Auto drain valves are essential components in compressed air systems that automatically remove condensate to prevent corrosion and maintain efficiency, and in India, suppliers like Airmax India, Kisna Pneumatics, Usha Pneumatics, Zen Air Tech, Concept Techno, Gem Equipment, and PRECO offer a variety of models with features such as adjustable intervals, zero air loss, durable construction, and compatibility with compressors, after coolers, and moisture separators, with selection depending on system size, pressure rating, and condensate type to ensure optimal performance and longevity.