Faced with serious concrete deterioration from
biogenic sulfide corrosion within collection systems,
engineers and municipalities are extending the
service life of wastewater conveyance structures with
the use of 100% solids polyamine systems designed
for hydrogen sulfide (H2S) permeation resistance. This article explains how sewer interceptors, manholes, and lift stations were protected using fluid-applied linings.
The heliport on a very large offshore structure
required complete coating removal and
replacement. The work could not be performed
during daylight hours because of a very busy and
crucial flight schedule, as well as safety concerns for
the workers from paint debris and metal loss. This
article describes the methods and materials used to
perform the work during nighttime hours. The
job was successfully completed in two weeks.
Re-engineering supply chains can reduce costs, cut
delivery times, provide a significant competitive
advantage, and enhance customer relationships.
Supply chain concepts can be applied to the
finishing phase (coating or plating) of production
to further cut costs and delivery times.
Components of water treatment plants (WTPs) are
susceptible to corrosion from constant immersion in water
and proximity to chlorine. A case history of corrosion
problems and their treatment at an Army WTP is
presented. Solutions included using high micro-silica
restoration mortar and advanced coal tar epoxy coatings.
Carbonated amine material, often called amine
blush, is the reaction product of the amine
functional curatives in epoxy paint with carbon
dioxide (CO2) and water vapor. This article explains the formation of amine blush and discusses factors controlled by the applicator and those controlled by the paint manufacturer.
Proper surface preparation is an essential preliminary step for any coating application. It is false economy to skimp on surface preparation in the belief that the coatings applied will compensate for surface deficiencies. This is especially true of high-performance coating materials.
This article outlines the results of a long-term
pipeline integrity plan that was used to rehabilitate
large segments of a natural gas pipeline over the past
eight years. Part 1 of this article discussed the details to be followed in an effective rehabilitation plan to accomplish the goal of a well-maintained pipeline system.
Molybdenum-bearing stainless steels and nickel
alloys can experience catastrophic oxidation. This
occurs during oxidation of molybdenum-bearing
materials and is caused by the action of
molybdenum trioxide (MoO3) as an oxidation catalyst. This article explains the oxidation
phenomenon and suggests ways to prevent it.
An excellent coating job can be ruined by
mechanical damage during shipping and
installation of the coated piece. Coating repairs can
be time-consuming, expensive, and may yield an
inferior coating job. This article provides
precautions to be taken to minimize coating
damage subsequent to initial coating.
This article describes the pipeline rehabilitation
program developed by the natural gas transmission
company in Colombia, South America. Part 1
presents the work accomplished to develop the
Effective Rehabilitation Plan (ERP). Part 2 discusses the ERP in detail, including results and accomplishments.
The four basic elements of a corrosion cell are an anode, a cathode, and the metallic and electrolytic pathways between them. Corrosion control can be achieved by eliminating (or reducing) any of these elements. One such method is to modify the electrolytic pathway by introducing a barrier between the threatened metal surface and the corrosive medium (i.e., by applying some kind of coating).
This article discusses the challenges involved with
coating contact, or “faying,” surfaces of steel
building components that are bolted together.
The use of certain zinc-rich primers is one successful
solution, provided the primers meet required
parameters for slip coefficient.
The prediction of coating life depends on many
factors, including the coating system used,
preparation and application methods, and the
severity of the environment. This article describes
the knowledge needed to estimate coating
life and the conditions that can compromise
Inorganic zinc (IOZ) coatings are used pervasively
in industry to provide reliable protection from
corrosion on a variety of substrates. Problems have
emerged with coatings applied over zinc primers,
however, such as delamination and blistering.
This article discusses proper curing methods for
IOZs to ensure dependable performance of the
entire coating system.