WHY MUST WE ONLY USE SPECIALIZED CLEANERS ON GAS TURBINE ENGINES?

Some operators of gas turbine engines have reportedly used all-purpose household cleaners to clean the compressor section of their engines. While these cleaners generally do a good job at general-purpose cleaning and degreasing around the home, they are not suitable for use in gas turbine engines, either on-line or off-line.We examined a concentrated spray cleaner which is widely available. When compared with the requirements of gas turbine OEM specifications the results were:

Parameter Requirement Actual result
Potassium + Sodium
(Concentrate)
25ppm maximum 10,200ppm
(as used) 0.5ppm maximum 1,020ppm
Ash at 800C 0.01% maximum 1.92%
pH 6.5 – 7.5 9.52

Such high levels of alkali metals (Potassium and Sodium) are incompatible with the good upkeep of gas turbine engines and would be expected to result in corrosive attack of the materials used in the hot section.

The high ash content may also block turbine blade cooling holes and lead to build up of deposits on the blade surfaces.