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Our patented hydraulic and diesel tank access system provides an
economical way to access and seal hydraulic and diesel tanks. These covers are
designed for ease of servicing hydraulic and diesel reservoirs through tank
sidewalls or tank tops. The design includes a self-centering and anti-rotation
feature to create a fast and positive seal for your hydraulic or diesel tank. The
design requires no additional parts to fabricate, no machining, and no welding is
required thus offering a considerable cost savings. Eliminating any welding has the
additional advantage that no weld generated contaminates are introduced into the
tank. When the hydraulic or diesel tank is fabricated, two or four tabs are cut when
the access hole is formed during laser or plasma cutting. The tabs are then bent
inward at 90 degrees to leave the hole completely round. Two shoulders on the
inner cover then align with these tabs to self-center the cover and provide anti-
rotation of the inner cover when tightening the bolt. A gasket under the outer cover
plate and o’ring under the shoulder bolt complete the seal when the bolt is torqued
down. The tank tabs are also designed to prevent the inner plate from dropping
inside the tank when the bolt is removed completely during disassembly.

Features Include

  •  Positive O’Ring Bolt Seal

  •  Full bolt torque load rated

  •  Heavy duty Grade 50 steel construction

  • Designed for air impact gun installation

  •  Quick easy access for cleaning and inspection

  • Self-centering for guaranteed sealing

  • Anti-rotation for inner cover

  • 6”, 8”, 10”, 12” and 14” sizes available

  • Pressure tested (recommended to test each design application)


  • Zinc plating options available

  • High temperature gaskets and o’ring for powder coat painting operations to 450 degrees F.

  • Several tab design options

  • Inner plate retention during disassembly

  • Tab bender tool

  • Consult factory for other options required

Selling points of FCC tank access system

1. Can be used on almost any mobile or stationary diesel or hydraulic tanks that would need access
for cleaning.
2. Tanks that currently have multiple bolt patterns and welded components used to seal the diesel
or hydraulic tanks, are typically expensive sealing systems. The FCC system offers great cost
savings compared to these.
3. With the FCC system, there are no additional parts to fabricate, no machining, and no welding
which is a big source of contaminates, and you save time in assembly with only one bolt to
4. If currently powder coat painting your tanks you can use this system with the high temp gasket
and o’ring to eliminate having to handle the tank after painting and assemble it right on the
5. The molded gaskets are UL tested for the new diesel fuel additives in the low sulfur fuel coming
on the market. The new 8, 10, 12, and 14-inch sizes use a molded gasket that wraps around the
edge and is capable of much higher clamps loads than any competitors design. There is a 6-inch
V48 material gasket for diesel tanks also.
6. The cover can be added to an existing tank not only as a cost saving, but also to improve the
cleaning ability or inspection of a tank if it has an existing “blind spot”.
7. For those tanks that have multiple hose connection points on an existing tank cover plate, the
FCC system would add a service point to inspect the tank without having to remove hoses.
8. There is a zinc plated cover option which would eliminate the possibility of the inner plate
rusting if the component was “to sit on the shelf” for any length of time. Also during normal
operation a diesel or hydraulic tank breathes and over time, any unprotected surface inside the
tank will develop rust.
9. Thin wall tanks with material thinner than 12 gage steel should be pressure tested as they
typically don’t have the structural integrity to seal with this type of a cover plate. There are ways
to reinforce the hole, including special tab designs. If you have questions on thin wall tanks,
please call to discuss the application.
10. Avoid placing this cover in a place that would allow high impacts during operation. For example
on a mobile machine, if the tank were located such that a stump, rock or other ground debris
could impact the cover with the full momentum of the machine weight, the cover could fail.
11. Use the short tab hole pattern where the tank is small enough such that the inner cover plate
does not need to be captured if the center bolt is removed. The other advantage of using the
short tab is that the cover can be preassembled before installing in the tank.
12. Use the capture tab hole pattern if the tank is large enough such that the inner cover needs to
be retained from falling down inside the tank. The capture tab holds the inner cover in place
even if the bolt is completely removed during disassembly. (video)
13. If you are having problems with your existing covers sealing when using a pressurized breather
the FCC system is rated for full bolt torque load which results in much higher pressure rating.
14. If you are currently using the EC style cover with the plastic washer, the same size cover can be
supplied with the o’ring flange bolt seal design with a better gasket and much higher bolt torque
clamp load for the best sealing.
15. Finally, you should test in your application. Fleenor Manufacturing Inc.’s policy is to provide free
samples for customers to build prototype tanks and test in their application.

If there is a question or concern about any option please contact us at

FCC Tank Access System: Project
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