Bundesanstalt fur Materialforschuing und -prufung


Test Report on testing a lubricant
for Reactivity with Gaseous and Liquid oxygen

Test Sample: LOX-8 PASTE, LOX-8 GREASE, FORMULA-8

Lubricants were tested for gaseous oxygen service
at operating temperature up to 60°C
and for liquid oxygen service


Reactivity with Liquid Oxygen on mechanical impact

Test Sample: LOX-8 PASTE, LOX-8 GREASE, FORMULA-8

At a drop height of 1m of the falling weight
(impact energy 750 Nm)
no reactions of the lubricants with liquid oxygen
could be observed in ten separate tests


Ignition Sensitivity to Gaseous Oxygen Impacts

LOX-8 PASTE, LOX-8 GREASE, FORMULA-8

SAMPLE TEMPERATURE
OXYGEN PRESSURE
REACTION ON IMPACT
ta
Pa
Pe
  
       
LOX-8 PASTE
     
60°C
1 bar
40 bar
no reaction*
60°C
1 bar
60 bar
ignition on 1. impact
60°C
1 bar
50 bar
no reaction*
60°C
1 bar
50 bar
no reaction*
 
      
LOX-8 GREASE
 
 
 
60°C
1 bar
80 bar
ignition on 1. impact
60°C
1 bar
70 bar
no reaction*
60°C
1 bar
70 bar
ignition on 1. impact
60°C
1 bar
60 bar
no reaction*
60°C
1 bar
60 bar
no reaction*
 
 
 
 
FORMULA-8
 
 
 
60°C
1 bar
60 bar
no reaction*
60°C
1 bar
80 bar
no reaction*
60°C
1 bar
100 bar
no reaction*
60°C
1 bar
200 bar
ignition on 1. impact
60°C
1 bar
180 bar
ignition on 4. impact
60°C
1 bar
170 bar
ignition on 5. impact
60°C
1 bar
160 bar
no reaction*
60°C
1 bar
160 bar
no reaction*
       
The test method is described in Annex 1
 
 
* within a series of
five consecutive impacts


Evaluation

On basis of the test results, there are no objections with regard to technical safety to use the lubricants names below in valves and fittings or other components for gaseous oxygen service at temperatures up to 60¡C and specific pressures as follows:

LOX-8 PASTE - 50 bar
LOX-8 GREASE - 60 bar
FORMULA-8 - 160 bar

There are also no objections to use these lubricants in components for liquid oxygen. In this case, a limitation to a particular pressure range is not necessary as compression of liquid oxygen causes no significant changes in concentration and therefore has no considerable influence on the reactivity of the lubricant.


Annex 1

Testing for Ignition Sensitivity to Gaseous Oxygen Impact

The sample is placed into a heatable steel tube. The sample tube is connected by a 750 mm long pipe and a pneumatically operated quick opening valve to a high-pressure oxygen accumulator.

A heater allows setting the sample tube to the test temperature ta. After the tube and pipe are at test pressure pa, the quick opening valve is opened and preheated. Oxygen of 60¡C and of presssure pe flows abruptly into the pipe and tube. In this way, the oxygen in the tube and in the pipe is almost adiabatically compressed from pressure pa to pe and heated. If there is a reaction of the sample with oxygen, indicated by a steep temperature rise in the tube, further tests with a new sample are performed at a lower pressure ratio pe/pa. If however, no reaction of the sample with oxygen can be detected after a waiting period of 30 seconds, the tube is de-pressurized and the test is repeated (up to four times) until a reaction takes place. This means, each test series consists of a maximum of five single tests with the same material under the same conditions. If no reaction can be observed, even after the fifth single test of a test series, testing is continued with new samples at greater pressure ratios pe/pa, until finally that pressure ratio is determined, at which time no reaction can be observed within a test series of five single tests. If the repetition of that test series with a new sample shows the same result, the test can be finished or continued at a different test temperature ta.

Testing for Reactivity with Liquid Oxygen on Mechanical Impact

The sample is placed into a sample cup. Liquid oxygen is poured over the sample which is then exposed to the mechanical impact of a plummet. The drop height of the plummet can be varied.

A reaction of the sample with liquid oxygen is usually indicated by a flame and a more or less strong noise of an explosion. The impact energy, at which no reaction occurs, is determined in varying the drop height of the plummet. This result shall be confirmed in a series of ten consecutive tests under the same conditions. The tests are finished, if reactions can be observed at impact energies of 125 Nm or less (equivalent to a drop height of the plummet of 0.17 m or less.) In this case, with regard to technical safety, the material is not suitable for liquid oxygen service.