FTM 3433 (FED-STD-791 Method 3433) Compatibility of Synthetic Aircraft Turbine Lubricants with Silicone Rubber
Elastomers are frequently exposed to lubricating oils during normal usage. If an elastomer absorbs the oil it may swell – a small amount of swelling is allowable and may help to avoid lubricant leakage; an excessive amount of swelling or any shrinkage may result in lubricant leakage and is detrimental. Swelling is usually accompanied by changes in the mechanical and physical properties of the elastomer: tensile strength, elongation, and hardness. These properties are also important in the elastomer’s ability to maintain a proper oil seal. This test determines the amount that an elastomer swells or shrinks when exposed to a test lubricant. Also determined are the tensile strength, hardness, and elongation changes of the elastomer due to exposure to the oil.
The original tensile strength, volume and hardness of the elastomer are determined. The elastomer is submerged in the lubricant and brought to the test temperature for the test time. The tensile strength, volume and hardness are determined after exposure. Reported are the changes in tensile strength, hardness, and volume of the elastomer.
Petro-Lube offers several tests to determine the swell of elastomers. Selecting the best method should be based on the elastomer of interest and specification of interest. Consider this test (FTM 3433) for silicone rubber in Aircraft applications. Consider ASTM D1414 for ‘O’ rings. Consider AAR M-914 for elastomers used in brake cylinders. Consider FTM-3603 for NBR-L (AMS3217/2C) and FTM 3604 for NBR-H (AMS3217/1B) or FKM (AMS3217/4A). Please call us for custom requests using standard elastomers or elastomers supplied by you for your specific application.
Sample size: 500 ml
- AAR M-914 ¶ 2.6 – Oil Swell of Brake Cylinder Elastomers
- ASTM D1414 – Compression Set of Elastomers
- ASTM D1414 – Rubber Swell of ‘O’ Rings
- FTM-3603 – Swelling of Rubber NBR-L (AMS3217/2C) @ 168 hours
- FTM-3604 – Swelling of Rubber NBR-H (AMS3217/1B) @ 168 hours
- FTM-3604 – Swelling of Rubber NBR-H (AMS3217/1B) or FKM (AMS3217/4A) @ 72 hours