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Concorde Hydraulic Oil
Concorde also used a special hydraulic fluid, Chevron M2-V.
This is a silicate ester mineral based fluid, as opposed to the phosphate ester based Skydrol, used by the subsonic airliners.
M2-V, is a high temperature fluid of the POLYSILOXANE (Ester Silicate) type, and able to resist temperatures ranging from – 60° C (- 76° F) to + 2300 C (+ 446° F) and having a sufficiently high bulk modulus.
The reason that they went for a different fluid such as M2V was a simple one;
Skydrol is useless at the high temperatures that Concorde operated at, in fact it’s no good at all because it is not chemically stable at very high temperature
They needed something better and in M2V they found the perfect fluid. Another interesting fact is that unlike Skydrol, that attacks paintwork, certain rubber seals, skin, engineer’s eyes etc, M2V is completely harmless you could even wash your hair in it, but I wouldn’t recommend it.
The main properties of CHEVRON M2-V are as follows :
Viscosity
- 54° c (- 65° F) 2.650 C.S.
38° C (100° F) 16.9 C.S.
99° C (210° F) 5.45 C.s.
177° C (350° F) 2.12 C.s.
Flash point
216° C (420° F)
Fire point
240° C (465° F)
Self igniting temperature
404° C (760° F)
Acidity index
0.04 mg KoH/gm
Density at 15° C (59° F)
0.9464
Flow point
- 80° C (-110° F)
Vapour tension
0,58 mm Hg at 204° C (400° F)
Thermal expansion coefficient between – 46° C (- 50.8° F) and 260° C (500° F)
0.001 volume unit per 0 C
Bulk modulus
(Adiabatic) at 100° C (212° F)
and 275 bars (3990 psi): 1~1.700
bars (170 psi)
The Hydraulics constitutes the lifeblood and muscle of Concorde. Without the Chevron M2V coursing through the network of pumps, pipes and valves, the lights would be on, but nothing would stir
There are three separate independent hydraulic systems. There are two main systems identified as Green and Blue and a standby system called yellow, which is available at any time for back-up purposes. Each of these systems is powered by two engine driven-pumps.
Certain precautions have to be observed while filling, topping-up or the lowering of the level of the Green, Blue and Yellow hydraulic tanks. Under no circumstances must the hydraulic fluid be mixed with water or any other fluid, you also have to be carful not to allow it to mix with the air. Once any of these substances has contaminated the M2-V, it becomes unusable.
THE CAPACITY OF THE HYDRAULIC TANKS
STORAGE AND HANDLING OF CHEVRON M2-V HYDRAULIC FLUID
As already stated above, Chevron M2V hydraulic fluid is based on a silicate ester (polysitoxane), with additives. It is light amber in colour and has a slight odour. Contamination by other fluids causes discolouration, and therefore correct storage of Chevron M2V hydraulic fluid is essential to prevent its contamination prior to use. Although Chevron M2V is essentially non-toxic, it must be handled with care at all times.
The cleanliness of Chevron M2V hydraulic fluid must conform to a standard, which defines the cleanliness standard relative to particle the contamination count. Every effort must be made to ensure that the values quoted are not exceeded; otherwise the M2-V becomes useless and therefore unusable.
TABLE 1:
The maximum contamination levels for Chevron M2V hydraulic fluid, as received from the manufacturer, are detailed below
PARTICLE SIZE MAXIMUM NUMBER
(MICRONS) OF PARTICLES PER 100 ML
5-15 7000
15 – 25 1500
25 – 50 300
50 and above 20
Fibres 3
TABLE 2:
The level of contamination for fluid used in static test rigs must not exceed the values detailed below:
PARTICLE SIZE MAXIMUM NUMBER
(MICRONS) OF PARTICLES PER 100 ML
5-15 14000
15 – 25 3000
25 – 50 600
50 and above 25
Fibres 3
TABLE 3:
The details below show the maximum contamination levels for the aircraft hydraulic systems and ground functioning rigs.
PARTICLE SIZE MAXIMUM NUMBER
(MICRONS) OF PARTICLES PER 100 ML
5 – 15 32000
15 – 25 5700
25 – 50 1012
50 – 100 180
Over 100 32