What is Nefras: Properties, Types, and Applications
Nefras is a general term for petroleum solvents, a type of straight-run gasoline. Its essence is clear from the term itself, which derives from “petroleum solvent.” This type of liquid is used in industry and everyday life for thinning paints, cleaning parts, removing stains, and applying antiseptic coatings.
Fractional (Chemical) Composition and Properties
Nefras is a clear liquid with an oily structure and a characteristic petroleum odor. It is toxic and highly flammable. Depending on the boiling point, the following products are obtained:
- Low boiling point (gasoline) – boils below 150°C.
- High boiling point (paraffin) – boils above 150°C.
Key properties include:
- Rapid dissolution;
- Stable quality;
- Corrosive aggressiveness;
- Minimal deposit formation;
- Ability to remove contaminants from metal surfaces.
Nefras markings
Nefras markings reflect their hydrocarbon composition. Accordingly, several groups of solvents are distinguished.
- 50% of normal hydrocarbons are paraffinic, designated by the letter ‘P’;
- 50% of naphthenic hydrocarbons are naphthenic, designated by the letter ‘I’;
- 50% of aromatic hydrocarbons are aromatic, designated by the letter ‘A’;
- 50% of isoparaffin hydrocarbons are isoparaffins, designated by the letter ‘I’;
- All of the above groups do not exceed 50% – mixed, designated by the letter ‘C’.
In addition to compositional characteristics, markings reflect the concentration of the aromatic fraction. According to this criterion, several subgroups can be distinguished:
- 0 – Aromatic hydrocarbons less than 0. 1%;
- 1 – 0. 1-0. 5%;
- 2 – 0. 5-2. 5%;
- 3 – 2. 5-5%;
- 4 – 5-25%;
- 5 – 25-50%.
The marking also indicates the boiling point limits. Therefore, the designation would be Nefras-C2 80/120. Mixed solvents with an aromatic hydrocarbon concentration of 0. 5-2. 5% and a boiling point of 80-120°C.
Types of Nefras
All currently produced Nefras solvents are listed in the reference appendix to GOST 26377-84. The table lists 15 solvents, their names, OKP (All-Russian Product Classification) codes, and regulatory documents. The list includes:
- Solvents used for technical purposes: Nefras-S-50/170.
- White spirit – Nefras-C4-155/200, and its alternative, Nefras-C4-150/200.
- Solvents used in the production of rubber products: Nefras-C2-80/120 and C3-80/120.
- Extracted gasoline: including straight sections Nefras-S2-70/85 – Nefras-S3-70/95.
- Heptane solvents – Nefras-S3-94/99.
- Aromatic petroleum solvents – Nefras A-150/330.
- Solvents for the logging industry – Nefras-S3-105/130.
- Hexane solvents: Nefras-P1-65/75, P1-63/75 and P1-65/70.
- ‘Alfor’ – Nefras-N2-220 / 300.
- Oil and heavy oil solvents: Nefras-A-130/150 and A-120/200, respectively.
- Oil ether fraction – Nefras-P4-30/80.
- Nefras for household use against insects – Nefras-I2-190/320.
Methods of obtaining
Nefras, a type of straight-run distillate gasoline, is produced by distilling oil at a temperature not exceeding 180°C. In addition, secondary petroleum fractions can be used.
Methods (area) of application
Nefras is used in the paint and varnish, wood chemical and low-extraction industries. It can remove organic contaminants from metal surfaces and is therefore used to clean containers before filling with petroleum products and as a cleaning agent for machinery that is in constant contact with motor oil and petroleum products. Dirt, plaque and dry stains are easily removed by washing with these products.
Other uses:
- Thinning of paints, varnishes and enamels, including oil-based paints and varnishes for electrical insulation;
- Degreaser for leather, fabric and metal surfaces before painting or gluing.
- Production of mastics and printing inks;
- Production of rubber adhesive mixtures and products (hoses, flat rubber products).
- Extraction of vegetable oils.
Features of transportation and storage
According to Appendix 1 of GOST 1510-84, petroleum solvents can be stored in the following tanks.
- Horizontal low pressure metal tanks;
- Vertical with or without pontoons, floating roofs and gas pipelines.
- Metal cans and barrels.
Transportation is carried out through large oil pipelines using rail, road, sea and air transport. For this purpose, special tanks are used with equipment for bottom filling and draining, with internal vapor- and oil- and petrol-resistant protective coatings that meet the requirements of electrostatic spark safety.
Regulatory documents (GOST, TU)
The NEFRAS designation sequence is established by GOST 26377-84. Technical specifications for Nefras-S 50/170 are given in GOST 8505-80. Other brands are produced according to TU, for example, TU 38. 101809-80, TU 38. 101703-77, TU 38. 101303-85, TU 38. 101453-77.
