Patent attributes
A maintenance pipe (30) used during maintenance of an exhaust purification device equipped with: a set of an oxidation catalyst (22) and a filter (23) for purifying exhaust gas from an engine (10); an upstream connecting pipe (16A) and a downstream connecting pipe (16B) which are mounted in a demountable way and guide the exhaust gas from the engine (10) to the oxidation catalyst (22); and an exhaust pipe injection device (24) and injectors (12) for increasing a concentration of unburned fuel contained in the exhaust gas. The maintenance pipe includes a flanged steel pipe (31) mounted to be replaceable with the downstream connecting pipe (16B), and a maintenance catalyst (32) that is housed in the flanged steel pipe (31), generates heat caused by oxidizing the unburned fuel contained in the exhaust gas from the engine (10), and heats the exhaust to discharge the exhaust to an exhaust downstream side.