Pipeline anticorrosion specification

Equipment and pipeline coating anti-corrosion design and construction specifications

1 General

1.1 This specification applies to petrochemical steel equipment, pipelines and their ancillary steel structure of the external surface coating anti-corrosion corrosion engineering.

This specification does not apply to the surface temperature of more than 500 ℃ equipment and pipeline corrosion protection of the external surface coating.

This specification does not include equipment and pipeline surface color and long-distance pipeline coating corrosion prevention.

1.2 The implementation of this specification should also comply with the provisions of the current relevant mandatory standards and norms.

2 Nouns, terms

2.1 coating coating

Coated on the surface of the object can form a protective, decorative or special properties (such as insulation, corrosion, etc.) of the solid film of a class of liquid or solid materials in general. In the name of specific paint varieties available "paint" word "paint", such as anti-rust paint, acid-resistant paint.

2.2 paint film or paint film paint film

The paint is evenly coated on the surface of the object formed by the continuous film, which can be composed of one or several coats.

2.3 varnish vernish

No coloring material of a class of paints, often used as a topcoat, can form a protective, decorative or special properties of the transparent film.

2.4 magnetic enamel enamel

After coating, the formation of the film is hard. The appearance is usually similar to a class of enamel paint, flat and smooth.

2.5 primer or priming coat

Multi-layer coating, directly coated on the surface of the steel coating.

2.6 two primer surfacer

Multi-layer coating, used to correct the uneven primer surface of a class of paint.

2.7 intermediate coat or intermediate coat

Between the primer and the surface layer of the coating, its main role is to increase the thickness of the corrosion protection coating, and can be good with the primer and the topcoat adhesion.

2.8 top coat or top coat

Multi-layer coating, coated in the top layer of paint, usually l-2.

2.9Adherend

Mainly including welding slag, welding spatter, soluble salts, grease, dirt, oxidized skin, rust and old paint coatings.

2.10 covering power covering power

In the object surface evenly coated with a layer of paint, so that the surface of the object is completely covered and no longer present the original state. At this time, the number of grams of paint used per square meter is called covering power. Unit: g/m2.

2. 11 adhesion adherence

Adhesion indicates that the paint film and the coated material two material surfaces through the role of physical and chemical forces combined together firmly. Generally used "level" to express.

2.1 2 difficult soluble mediumslightly soluble medium

Temperature 20 ℃, the solubility in water is less than 2g / L alkali, salt medium.

2.13 easily soluble mediumsoluble medium

Temperature 20 ℃, the solubility in water is equal to or greater than 2g / L of alkali, salt media.

2.14 slightly hygroscopic medium slightly hygroscopic medium

Temperature 20 ℃, the relative equilibrium humidity is equal to or greater than 60% of the alkali, salt medium.

2.15 easily hygroscopic medium hygroscopic medium

Temperature 20 ℃, the relative equilibrium humidity is less than 60% of the alkali, salt media.

3 Design

3.1-General provisions

3.1.1 The selection of coatings should comply with the following principles:

1 Compatible with the use of the environment of the coated object:

2 Compatible with the surface of the coated object material;

3 The correct matching of the layers of paint;

4 Safe, reliable and economically reasonable;

5With construction conditions.

3.1.2 Carbon steel, low alloy steel equipment, piping and its ancillary steel structure surface should be painted.

3.1.3 painted on the steel surface of the primer, it is appropriate to use the current national standard "paint film adhesion determination method" GB / T1720 in the determination of adhesion for the first level of primer.

3.1.4 Unless otherwise specified in the design, the following should not be painted:

1 Austenitic stainless copper surfaces:

2 galvanized surfaces; :

3 surfaces that have been finished:

4 surfaces coated with plastic or coated with variegated paints:

5 nameplates, sign boards or tags.

3.1.5 Stationary equipment, piping, and their appurtenant steel structures fabricated at the manufacturing plant shall be primed as required by design. equipment, pipelines and their attached steel structures. Pipelines and their ancillary steel structures.

3.1.7 Buried equipment and pipelines shall be coated against corrosion.

3.1.8 Corrosive substances in the atmosphere on the surface of steel corrosion, can be divided into strong corrosion, moderate corrosion, weak corrosion according to its degree of corrosion of three categories, see Table 3.1.8.

Table 3.1.8

Corrosive substances and the role of the conditions

Corrosive degree of corrosion