The FC01015 from Cleveland Tank is a 2.125-inch diesel fuel cap built for fuel systems that don’t call for a locking closure. It has a female thread design at 8 threads per inch (8 TPI), matching the thread pitch used across Cleveland Tank’s larger locking caps, so it’s easy to spec correctly even though the diameter is smaller. Machined from lightweight, corrosion-resistant aluminum, it resists the rust and pitting that shorten the life of a steel cap. Non-locking and non-vented, the FC01015 is a straightforward, direct-fit replacement for diesel fuel tanks specifying a 2.125-inch, 8 TPI female-thread cap. It weighs 1.0 lb.

The FC01015VNT from Cleveland Tank is a vented, non-locking diesel fuel cap built for fuel systems that rely on the cap itself — not a separate equalizer line — to let air into the tank as fuel is drawn down. It has a 4.00-inch diameter and female threads at 8 threads per inch (8 TPI), machined from lightweight, corrosion-resistant aluminum. Fitting a non-vented cap on this type of system risks vacuum lock, so the FC01015VNT is specced to avoid that while keeping the tank sealed against leaks and contamination. It weighs 1.0 lb at 4.0 x 4.0 x 2.0 inches and installs as a direct-fit replacement for diesel fuel tanks specifying a 4.00-inch, 8 TPI vented cap.

The FC1015 from Cleveland Tank is a brass locking diesel fuel cap with a male thread design, for fuel tank necks that take a male-threaded cap rather than the female style used on most of Cleveland Tank’s other caps. It has a 2.125-inch diameter and 12 threads per inch (12 TPI), and it’s both locking — deterring fuel theft and tampering — and vented, so the tank can equalize pressure properly as fuel is drawn down instead of risking vacuum lock. Brass construction gives it more heft and durability than Cleveland Tank’s standard aluminum caps. At 1.0 lb and 2.125 x 2.125 x 2.0 inches, the FC1015 is a direct-fit replacement for diesel fuel systems specifying a 2.125-inch, male 12 TPI locking vented cap.