Vents Overboard drain line Sump Standpipe Finger  screen Filler cap Baffle plates Scupper Drain valve Corrosion inhibitor Fuel tank straps 14-21 Figure 14-31.  A bladder fuel tank for a light aircraft. Figure 14-30.  A composite tank from a Challenger ultralight aircraft. Figure 14-28.  A fuel tank bay in the root of a light aircraft wing on  a stand in a paint booth. Padded straps hold the fuel tank securely  in the structure. Figure 14-27.  A typical rigid removable aircraft fuel tank and  its parts.  Figure 14-29.  A fuselage tank for a light aircraft.  tank but does not require as large an opening in the aircraft  skin to install. The tank, or fuel cell as it is sometimes called,  can be rolled up and put into a specially prepared structural  bay or cavity through a small opening, such as an inspection  opening. Once inside, it can be unfurled to its full size. Bladder  tanks must be attached to the structure with clips or other  fastening devices. They should lie smooth and unwrinkled in  the bay. It is especially important that no wrinkles exist on  the bottom surface so that fuel contaminants are not blocked  from settling into the tank sump.  [Figure 14-31] Bladder fuel tanks are used on aircraft of all size. They are  strong and have a long life with seams only around installed 