A drain tube device of a muffler for a fuel cell vehicle includes: the muffler included in an exhaust pipe of the fuel cell vehicle and having a front end part to which blower air is introduced and a rear end part from which the blower air is discharged; a drain tube having a drain hole disposed between the front end part and the rear end part of the muffler to downwardly discharge the blower air; and a hole cover part mounted in the drain hole to block a hydrogen discharge of the blower air and discharge only condensate water. The drain tube device maintains functioning of the muffler while discharging the condensate water and smoothing a flow of the blower air through the hole cover part mounted in the drain hole upon starting the vehicle.

A steam trap includes a replaceable condensate nozzle cartridge with a through passage forming a venturi nozzle in a straight-line working fluid flow path. The venturi through passage includes a venturi nozzle insert that reduces the pressure of the working fluid to cause the liquid water in the working fluid to flash and restrict the flow of steam through the passage. The condensate nozzle is located in a reduced pressure discharge chamber into which a nozzle outlet discharges water condensate extracted by the nozzle and emptied from a trap outlet. The reduced pressure discharge chamber has an access opening sealed by a removable cover to allow the nozzle cartridge to be removed and replaced if necessary, without removing the steam trap from the process line. Locating the removable nozzle cartridge in a lower pressure region of the steam trap overcomes rating limitations on prior steam traps with replaceable venturi nozzles.

A solution having a predetermined concentration is stably supplied to a use point, at which the amount of use of the solution changes, by only modifying currently-used equipment at a low cost and in a space-saving manner. In order to supply a solution containing a solute at a predetermined concentration from a preparation portion of the solution to a use point through a supply pipe, a retention portion that has no gas-liquid interface and at which the solution is retained is provided at an intermediate portion of the supply pipe. Even when the amount of use of the solution at the use point changes, the change is absorbed by the retention portion, whereby a solution having a predetermined concentration can be stably supplied to the use point.