These drain valves specially suitable for removing condensate having sludge and rust laden from compressed air systems. These drain valves find most suitable application for installation on compressors [after-coolers], dryers, receivers, drip legs, moisture separators, etc. Features include: fully automatic, no maintenance 12 mm orifice manual test switch indication for valve healthiness easy to replace specially suitable for drain sludge and rust laden condensate glass-filled nylon coil former a-ring seal on cycle adjustment pots to ensure weatherproof sealing small compact resistant abs timer.