Fire Fighting SIL study

I design one electrical power plant (a combined cycle) to supply steam and electricity to one Oil Refinery. Here all standards are based on API and the Client wants that my Water fire fighting and detection system shall be designed with SIL 3.
My DCS satisfy that but i need to make a SIL study in order to demonstrate that all system satisfy SIL 3.

Who can help me supplying a example SIL 3 study?

Thank you for your help.

josefreitas - If you can get a copy of ISA TR 84 00 04 Part 2, there is an example of an SIS implementation. There may be a similar example in one of the IEC 61511 series documents but I don't know. Perhaps someone with more expertise can jump in here.

have anybody one SIL study? A good example is better.