PURPOSE: To reduce a cost, to drastically shorten the working time for a sticking operation and to greatly improve the workability thereof by printing front surfaces with the coloration and characters meeting the kinds and systems of fluid pipings and respectively integrally forming arrows indicating the flow directions of fluid at the longitudinal end.

CONSTITUTION: The designation identifying stickers l, 5, 6 are printed with the coloration and characters meeting the kinds and systems of the fluid pipings on their front surfaces and are respectively integrally formed with the arrow parts indicating the flow directions of the fluid at the longitudinal ends. The stickers are stuck to the pipings 12 to 14 by adhesives disposed on the rear surfaces and, therefore, various kinds of the designation are made by the one sticker and the cost thereof is reduced. Further, the sticking of the stickers 1, 5, 6 only by the adhesives applied on the rear surfaces suffices is possible and, therefore, the easy sticking of the stickers even to the pipings having intricate structures is possible.