Fill-Coat #2 Pipeline Casing Fill by Trenton

Casing Filler Installed Cold From 55-gallon Drums


Fill-Coat #2 Casing Filler is a petrolatum wax based corrosion preventative compound used to fill the pipeline casing annulus. It is specifically designed for cold installation out of a 55-gallon drum for small quantity requirements. It prevents corrosion by displacing water that is present and preventing water from re-entering the casing. It remains in a firm gel consistency at ground temperatures commonly found in normal pipeline operations.

Water or water vapor is present in most pipeline casings, making possible galvanic corrosion of the carrier pipe. Also, a "water short" can occur through the water in the casing, allowing cathodic current to flow through the water and on to the pipe in the casing. Under these circumstances, cathodic current is increase and the casing is sacrificed as well. Casing filler prevents this from occurring. Further, in some instances the pipe may be shorted to the casing through a direct metal-to metal contact and filling the casing might correct this condition on some occasions. In any case, it is difficult if not impossible, to cathodically protect pipe in a casing, so that filling of the casing will protect the pipe from corrosion regardless of the circumstances.

When the casing is filled with FillCoat #2, it displaces accumulated water from the casing and prevents new water from re-entering through leaks in the seals or through condensation. Thus, corrosion that might have been occurring is prevented, cathodic current to protect the pipeline in the casing may be reduced, and the sacrifice of the casing by cathodic current flowing through casing is halted. This allows a film of casing filler material to coat the shorted contact surfaces of the pipe and casing. Since Fill-Coat #2 is electrically non-conductive, a metallic short may be corrected.

After being pumped into the casing, the filler remains as a firm gel, pliable enough to allow the carrier pipe to be removed if necessary. It is essentially inert and nonvolatile and will remain unchanged indefinitely.



  • Presents galvanic and atmospheric corrosion within casings.
  • Displaces and prevents re-entry of water in casing.
  • Satisfies DOT requirements for shorted casings.
  • Carrier pipe can be removed.
  • Inert, non-hazardous and non-volatile.
  • Pumpable at temperatures above 55°F without heating.
  • Economical for small quantity requirements.


Fill-Coat #2 Application

Fill-Coat #2 casing filler is delivered to the jobsite in 55-gallon drums. It is pumped by mastic pump out of the drums directly through the casing vent, until the casing void is filled and material discharges out the other vent. A 10:1 ratio mastic pump with follower plate is available from Trenton on a rental basis.

Adequate openings through the casing must be present where the vent is attached so that the flow of casing filler is not unduly restricted. As the casing is filled, air and water are purged out the opposite vent. It is preferable, although not necessary, that casing vents be installed with the low end vent attached to the bottom of the casing and high end vent attached to the top of the casing. This makes possible the removal of water prior to installation of casing filler either by blowing it out with an air compressor or pumping it out with a suction pump.

Installation of Fill-Coat #2 casing filler is an acceptable "other measure" under the code requirements of the Department of Transportation. The DOT code under Regulations for the Transportation of Natural and other Gas by Pipeline, Title 49 of the code of Federal Regulations, Part 192, Subpart 1, Section 192.467, Paragraph C which states, "Except for unprotected copper inserted in ferrous pipe, each pipeline must be electrically isolated from metallic casings that are a part of the underground system. However, if isolation is not achieved because it is impractical, other measures must be taken to minimize corrosion of the pipeline inside the casing." Fill-Coat #2 casing filler installed as an "other measure" to minimize corrosion is often much less expensive in the long term than increasing cathodic protection current or attempting to clear the short by other construction methods. 


Specific Gravity at 60°F
Pour Point
Flash Point

Dark brown
0.80 - 0.90
80 - 100°F
300°F min
55-gallon drums

Quantity Requirements

Pipe x Casing Size (inches) Quantity (gallons/foot)
4 x 8
6 x 10
8 x 12
10 x 14
12 x 16
14 x 20
16 x 20
20 x 24
22 x 26
24 x 30
26 x 30
30 x 34
30 x 36
36 x 42