Dec 11
6
What Is a Corrosion Inhibitor?
Written By: S.E. Smith
Edited By: O. Wallace
A corrosion inhibitor is a chemical compound which is designed to protect a metal or alloy from corrosion. While corrosion inhibitors will not halt or completely prevent corrosion, they can reduce the rate at which corrosion occurs, and block early corrosion damage. A wide variety of chemicals can be used for this purpose, although many are toxic, and must therefore be used with care to protect the environment.
Dec 11
6
Leak Testing Verifies Quality
by Jack Stewart
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Leak testing equipment is a type of nondestructive testing equipment used to measure the escape of liquids, vacuum or gases from sealed components or systems. Some configurations require a separate leak detector or sensor as an input. They are often equipped with various other components such as pumps, calibrators, gages and cases. A leak is a hole or porosity in an enclosure capable of passing a fluid from the higher pressure side to the lower pressure side.
Dec 11
6
How Ultrasound Works
The theory of airborne ultrasonic detection is relatively simple. Ultrasonic instruments are sensitive to sounds beyond the limits of normal human hearing. An ultrasonic detector translates ultrasonic signals to the range of human hearing. Frequency, the number of times a sound wave cycles from trough to crest, is expressed in Cycles per seconds and measured in “hertz.” One kilohertz (kHz), for example, is one thousand cycles per second. The best human ears can hear noises in the range of 20 hertz to about 20,000 hertz (20kHz). Many ultrasonic detectors start at approximately 20 kHz and work upward to sounds as high as 100 kHz. Thus mechanics using the ultrasound instrument can tune-in to and “hear” faults in electric transmission and distribution systems end in operating machinery, as well as leaks in vacuum or pressurized systems.
Dec 11
6
Inspection Test Plan (ITP)
An Inspection Test Plan (ITP) is a commonly required document that you’ll need to submit with your construction quality control plan. Whether you’re working on a private sector or government contract, clients today all want to see your inspection test plan. They want to know exactly what inspections and tests you’ll be forming to control quality on their project.
Iverson, WP | Olson, GJ
The corrosion of iron and steel in the form of storage tanks, pipelines, pumps, and other systems by sulfate-reducing bacteria is a serious problem faced by the petroleum industry. Recently, sulfate-reducing bacteria have been suspected of contributing to failure of certain enhanced (tertiary) oil recovery operations, possibly by degrading polymers used in situ as mobility control agents. Thus almost every aspect of oil recovery can be hindered by the ubiquitous sulfate-reducing bacteria. This review updates the earlier ones by presenting more recent information on the newly discovered strains of sulfate-reducing bacteria, on methods for the cultivation of sulfate-reducing bacteria on agar surfaces, on the bacterial dissimilatory sulfate reduction process, and on novel mechanisms of corrosion by these organisms.
Source: CSA
Moskowitz, L N
Commercially available thermal spray coatings have seen limited use in corrosion applications due to the presence of interconnecting porosity and oxide networks. Use of vacuum chambers or post-treatments can eliminate these defects, but these methods are impractical on a large scale. If similar high quality coatings could be produced in atmosphere and without post-treatments, then thermal spray techniques would offer important advantages as a means of building and repairing process equipment. A modified HVOF process employing unique inert gas shrouding has resulted in highly dense, low oxide coatings of metallic alloys. These coatings were extensively evaluated for severe petroleum industry corrosion applications in laboratory and plant testing, with exposures as long as five years. Coatings of corrosion-resistant alloys, such as Type 316L stainless steel and Hastelloy C-276, were shown to act as true corrosion barriers. They were protective to underlying base metals in severe environments, and in most cases exhibited corrosion resistance comparable to the corresponding wrought alloy. The process was called up for on-site plant use, and successfully applied to numerous corrosion problems in petroleum industry plant equipment. Significant technical and economic advantages can be realized by use of thermal spray coatings to sole plant equipment problems.
Descriptors: Chemical processing equipment | Coating | Carbon steels | Flame spraying | Austenitic stainless steels | Coatings | Nickel base alloys | Superalloys | Protective coatings | Corrosion resistance
Source: http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=199212581682MD&q=the+problem+of+petroleum+industry&uid=791269195&setcookie=yes
Nov 11
19
Corrosion in Petroleum Industry
The Petroleum industry contains a wide variety of corrosive environment s. Some of these, many are unique to this industry. Thus it is convenient to group all these environments together. Corrosion problems occur in the petroleum industry in at least three general areas: (1) production, (2) transportation and storage, and (3) refinery operations.
Production. Oil and gas fields consume a tremendous amount of iron and steel pipe, tubing, pumps, valves, and sucker rods. Leaks cause loss of oil and gas and also permit infiltration of water and silt, thus increasing corrosion damage. Saline water and sulfides are often present in oil and gas wells. Corrosion in wells occurs inside and outside the casing. Surface equipment is subject to atmospheric corrosion. In secondary recovery operations, water is pumped into the well to force up the oil.
Nov 11
18
Environmental problems by petroleum
The production and use of petroleum has given rise to several environmental problems. Toxic crude oil can be spilled on land or in water, poisoning plants and animals. The burning of fuels derived from petroleum releases toxic gases that pollute the air. Some scientists even believe that the burning of petroleum fuels contributes to global climate change. Spills and seeps. Petroleum can spill during many stages of its production, transportation, and consumption. Petroleum can leak from wells on land or in the sea. Pipelines can break, causing petroleum to spill during transportation. Oil tankers may collide or sink, releasing huge loads of crude oil into the water.
Nov 11
17
Stress Corrosion Cracking
Stress corrosion cracking (SCC) is caused by the simultaneous effects of tensile stress and a specific corrosive environment. Stresses may be due to applied loads, residual stresses from the manufacturing process, or a combination of both.
Cross sections of SCC frequently show branched cracks. This river branching pattern is unique to SCC and is used in failure analysis to identify when this form of corrosion has occurred.
Nov 11
17
Protective Coatings
Protective coatings are the most commonly used method of corrosion control. Protective coatings can be metallic, such as the galvanized steel shown below, or they can be applied as a liquid “paint.” Most of the research and testing of protective coatings at the Kennedy Space Center is related to paint-like protective coatings.
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 (Courtesy of www.corrosion-doctors.org) |
Filiform corrosion occurs underneath protective coatings. The air conditioner on the left is starting to show rust stains due to problems with protective coating. The same types of problems are starting to appear on the aluminum airplane wing shown on the right.
Source: http://corrosion.ksc.nasa.gov/microbial.htm