Armstrong Thermostatic Drain Valves are ideal protection of steam tracing, instrument tracing, condensate return lines, valves, fittings, pumps, safety showers, fire lines, spray nozzles and similar equipment. The valves operate by sensing either ambient or condensate temperature. Their unique ram-type plug and seat provide reliable, tight shut-off for longer periods than any other type available. All valves are 100% factory tested.