Unfortunately no, if the vessel is designed to ASME VIII it will require an ASME VIII coded safety valve, however the SRV in question may or may not be duel certified to both standards.
Sarah
BS5500 allows a maximum accumulation of 10% only and as such this is the limiting factor when sizing to API for firecase. It should be noted that this also restricts the overpressure allowance for multiple SRV's (116%)as well.
Sarah
