Types of lubricants: Lubricants are at following three types. 1. Solid: graphic, mica etc 2. Semi solid: grease 3. Liquid: Lubricants are obtained from animal fat, vegetables and minerals. Lubricants made of animal fat, does not stand much heat. It becomes waxy and gummy which is not very suitable for machines. Vegetable lubricants are obtained from seeds, fruits and plants. Cottonseed oil, olive oil, linseed oil and castor oil are used as lubricant in small machines. Mineral lubricants are most popular for engines and machines. It is obtained from crude petroleum found in nature. Petroleum lubricants are less expensive and suitable for internal combustion engines.
-Graphite is often mixed with oil to lubricate automobile spring. Graphite is also used as a cylinder lubricant. -Grease is used for chassis lubrication.
Grade of lubricants: Generally lubricating oils are graded by SAE (society of automotive engineers) method by assign a number to oil whose viscosity at given temperatures falls in certain range.
-Two temperatures -18ᵒC (0ᵒF) and 99ᵒC (210ᵒF) are used to assign the number ex-Single grade type: (a) SAE 5w,10w and 20w grades are viscosity at -18ᵒC (0ᵒF) and for
winter use. (b) SAE 20, 30, 40 and 50 grades lubricating oil are viscosity at 99ᵒC (210ᵒF) and for summer use.
Multi-grade type: ex- SAE 20W/50 oil has viscosity equal to that at SAE 20W at -18ᵒC and viscosity equal to that at SAE 50 at 99ᵒC
SAE grades of oil are based on viscosity but not quality based. API (American petroleum institute) used regular, premium and heavy duty type oil which are based upon properties of oil and operating conditions. Generally regular type oil is straight mineral oil, premium type contained oxidation inhibitors and heavy type contained oxidation inhibitors plus detergent-dispersant additives.
According to API,
For gasoline engine 5 service ratings oil are used: SA, SB, SC, SD and SE
For diesel engines 4 service ratings are use: CA, CB, CC and CD
Where S and C stands for SI and CI engines
Rating A is for light-duty service, the severity of service increasing towards rating D and E which is severe duty.
-Graphite is often mixed with oil to lubricate automobile spring. Graphite is also used as a cylinder lubricant. -Grease is used for chassis lubrication.
Grade of lubricants: Generally lubricating oils are graded by SAE (society of automotive engineers) method by assign a number to oil whose viscosity at given temperatures falls in certain range.
-Two temperatures -18ᵒC (0ᵒF) and 99ᵒC (210ᵒF) are used to assign the number ex-Single grade type: (a) SAE 5w,10w and 20w grades are viscosity at -18ᵒC (0ᵒF) and for
winter use. (b) SAE 20, 30, 40 and 50 grades lubricating oil are viscosity at 99ᵒC (210ᵒF) and for summer use.
Multi-grade type: ex- SAE 20W/50 oil has viscosity equal to that at SAE 20W at -18ᵒC and viscosity equal to that at SAE 50 at 99ᵒC
SAE grades of oil are based on viscosity but not quality based. API (American petroleum institute) used regular, premium and heavy duty type oil which are based upon properties of oil and operating conditions. Generally regular type oil is straight mineral oil, premium type contained oxidation inhibitors and heavy type contained oxidation inhibitors plus detergent-dispersant additives.
According to API,
For gasoline engine 5 service ratings oil are used: SA, SB, SC, SD and SE
For diesel engines 4 service ratings are use: CA, CB, CC and CD
Where S and C stands for SI and CI engines
Rating A is for light-duty service, the severity of service increasing towards rating D and E which is severe duty.
No comments:
Post a Comment