V. Find the suitable nouns to the verbs from List a. Make up your own sentences with the given phrases.

A. to meet to derive from to be contaminated to take to guard against to hide to withstand to offer to verify to raise

B. a. problems b. health objections c. defects d. petroleum asphalts e. the demands f. precautions g. coating’s integrity h. high temperature i. greater bonding strength j. hydrocarbons

VI. Read and translate the following text. Types of coatings

Different types of coatings are available to meet the contractual demands set out by the pipeline owners as well as to accommodate the preferences of individual contractors. The most widely used types are bituminous enamels, epoxy resins, and tapes.

Enamel Coatings. Bituminous enamels are derived from coal-tar pitches or petroleum asphalts. Because of their wide availability, low cost and ease of application, they have been widely used throughout the industry almost since its inception. Enamel coatings include a wide variety of petroleum-based derivatives such as asphalts, coal tars, greases and waxes, mastics, and asphalt mastics. Asphalts are substances that occur both naturally and as a byproduct of petroleum distillation, while coal tar is a mixture of tars formulated from the byproducts of coal distillation to which various filler substances have been added. Grease and wax are petroleum-based coatings containing corrosion inhibitors and fillers.

The use of grease and wax has declined markedly, and they are only rarely used in modern pipeline construction. Mastics are a mixture of asphalt, sand and miscellaneous fillers. They are used when a thicker, more durable consistency and greater adhesion are needed. Asphalt mastic, a form of coating that has been in use in the industry for over 50 years, is a dense mixture of sand, crushed limestone and fiber bound together with asphalt. As it is the thickest of all corrosion coatings, it is generally used in offshore pipelines.

Both asphalt mastics and the other enamel coatings are not suitable for use in areas where the soil has been contaminated with hydrocarbons.

With enamel coatings, the material in intimate contact with the pipe surface is the enamel. The sand, felt, fiberglass and other materials used as fillers function as mechanical reinforcement to protect the pipe during construction.

Enamel coatings are most effective when the pipeline’s operating temperature range is between 30⁰F and 180⁰F. Below 40⁰F precautions must be taken to guard against cracking and subsequent bonding problems.

Fusion-bonded Epoxy Coatings. Fusion-bonded epoxies are powdered resins that form a virtual skin over the steel surface when applied to heated pipe. They are usually applied at the mill because of the specialized equipment needed and the exacting pre-application requirements.

For maximum effectiveness and bonding strength, pipe surfaces must be blast-cleaned to a near-white finish. The entire pipe is then heated to a specified temperature, and a fine spray of powdered epoxy resin is directed onto the pipe surface. The resin melts on contact, and the residual heat of the pipe cures the coating and bonds it to the pipe.

The principal advantages of the fusion-bonded epoxies:

• the relatively thin coating they leave. Because defects are not hidden under a thick layer of coating or outer wrap, final inspection of the pipe surface is considerably easier.

• the coating’s strong resistance to handling damage and its overall durability and flexibility;

• fusion-bonded epoxies can also be applied to the internal surfaces of pipelines. Gas transmission lines in particular are more susceptible to internal corrosion because of the hydrogen sulfide, carbon dioxide and water found in natural gas.

• fusion-bonded epoxies can withstand the high operating temperatures (200⁰F or higher) commonly found in gas transmission lines.

Tape Coatings. Polyethylene tape is now being used more and more for line travel applied external pipe coatings. Although polyethylene is the most commonly used tape coating, several other types are also available. These include polyvinyl, coal tar base, and butyl-mastic adhesive coatings. New adhesives and primers that offer greater bonding strength are also being developed. Since the coating is applied on the line, its integrity can be immediately verified, and any defects can be repaired quickly and simply. The application procedure does not raise any serious environmental or health objections.