Abstract: The invention pertains to a composition based on a fluoroelastomer comprising nitrile or carboxylate-type cure sites and including a curing agent and a Br-containing marker having reactivity towards the said cure-sites, which can be cured so as to deliver cured parts maintaining chemically bound bromine atoms; this material, when submitted to wear/damage would hence release Br-containing contaminants, which can easily spotted via notably an on-line mass spectrometer, so as to monitor and anticipate critical failures of sealing materials based there upon.

Abstract: The invention pertains to a method of making cured parts from a composition comprising certain fluoroelastomers and certain bromine-containing compounds under conditions suitable for delivering cured parts possessing outstanding mechanical and sealing properties and incorporating suitable amounts of bromine-containing compounds, so that these cured parts, when submitted to wear/damage would release Br-containing compounds, which can easily detected using appropriate analytical techniques, so as to monitor and anticipate critical failures thereof.

Abstract: The invention pertains to a composition based on a fluoroelastomer comprising nitrile or carboxylate-type cure sites and including a curing agent and a Br-containing marker having reactivity towards the said cure-sites, which can be cured so as to deliver cured parts maintaining chemically bound bromine atoms; this material, when submitted to wear/damage would hence release Br-containing contaminants, which can easily spotted via notably an on-line mass spectrometer, so as to monitor and anticipate critical failures of sealing materials based there upon.

Abstract: The invention pertains to a composition based on a fluoroelastomer comprising nitrile or carboxylate-type cure sites and including a curing agent and a Br-containing marker having reactivity towards the said cure-sites, which can be cured so as to deliver cured parts maintaining chemically bound bromine atoms; this material, when submitted to wear/damage would hence release Br-containing contaminants, which can easily spotted via notably an on-line mass spectrometer, so as to monitor and anticipate critical failures of sealing materials based there upon.

Abstract: The invention pertains to a method of making cured parts from a composition comprising certain fluoroelastomers and certain bromine-containing compounds under conditions suitable for delivering cured parts possessing outstanding mechanical and sealing properties and incorporating suitable amounts of bromine-containing compounds, so that these cured parts, when submitted to wear/damage would release Br-containing compounds, which can easily detected using appropriate analytical techniques, so as to monitor and anticipate critical failures thereof.

Abstract: The invention pertains to a composition based on a fluoroelastomer comprising nitrile or carboxylate-type cure sites and including a curing agent and a Br-containing marker having reactivity towards the said cure-sites, which can be cured so as to deliver cured parts maintaining chemically bound bromine atoms; this material, when submitted to wear/damage would hence release Br-containing contaminants, which can easily spotted via notably an on-line mass spectrometer, so as to monitor and anticipate critical failures of sealing materials based there upon.

Abstract: To evaulate the working line characteristics of a compressor of a gas turbine engine, fuel is supplied from the gas turbine engine fuel supply to a fuel accumulator via a control valve. The control valve is closed when a predetermined quantity of fuel is in the fuel accumulator, and a three way valve is adjusted to allow high pressure fluid from a fluid cylinder into the accumulator to pressurize the fuel. The fuel is then supplied from the accumulator via the valve to a combustion chamber to be burnt to increase the pressure in the combustion chamber and hence the compressor. The pressure of the fuel supplied which causes a surge is indicative of the working line characteristics of the compressor. The pressure and quantity of fuel supplied are varied until a surge is produced.Reworking of compressors with reduced surge margin can be carried out. Enables evaluation to take place while the engine is fixed to an aircraft.

Abstract: To evaluate the working line characteristics of a compressor of a gas turbine engine, fuel is supplied from the gas turbine engine fuel supply to a fuel accumulator via a control valve. The control valve is closed when a predetermined quantity of fuel is in the fuel accumulator, and a three way valve is adjusted to allow high pressure fluid from a fluid cylinder into the accumulator to pressurize the fuel. The fuel is then supplied from the accumulator via the valve to a combustion chamber to be burnt to increase the pressure in the combustion chamber and hence the compressor. The pressure of the fuel supplied which causes a surge is indicative of the working line characteristics of the compressor. The pressure and quantity of fuel supplied are varied until a surge is produced.Reworking of compressors with reduced surge margin can be carried out. Enables evaluation to take place while the engine is fixed to an aircraft.

Abstract: To evaluate the working line characteristics of a compressor of a gas turbine engine, fuel is supplied from the gas turbine engine fuel supply to a fuel accumulator via a control valve. The control valve is closed when a predetermined quantity of fuel is in the fuel accumulator, and a three way valve is adjusted to allow high pressure fluid from a fluid cylinder into the accumulator to pressurize the fuel. The fuel is then supplied from the accumulator via the valve to a combustion chamber to be burnt to increase the pressure in the combustion chamber and hence the compressor. The pressure of the fuel supplied which causes a surge is indicative of the working line characteristics of the compressor. The pressure and quantity of fuel supplied are varied until a surge is produced.Reworking of compressors with reduced surge margin can be carried out. Enables evaluation to take place while the engine is fixed to an aircraft.