A seal arrangement configured to provide an airtight and fluid-tight seal between a first component and a second component, having a first pressure boundary seal disposable at least partially within the gap between the first component and the second component, the first pressure boundary seal being fixable to one of the first or second components to create an airtight seal with the other of the first or second component, the seal arrangement also having a first flame deflector that is configured to bridge across and cover the gap between the first component and the second component so as to create a fluid-tight seal over the gap between the first component and the second component, where the first flame deflector has a convex external shape so as to prevent any fluid impinging upon the first flame deflector from pooling on the first pressure boundary seal.