Design Philosophy for Fuel Gas KODs

[MIANCH]

Hi all,
this is very simple question but i cannot find guide lines (codes & standards) for the selection of fuel gas KODs for high pressure and low pressure separately while fuel gas supply sources is same. can anyone explain me why two KOD required and why we cannot use single KOD,if reference material posted here will be more helpful.
Best Regards

 

[EmmanuelTop]

You cannot use a single KOD because you have 2 (two) fuel gas systems operating at different pressures.



There is no such thing as "common sense" - Apollo RCA

 

[MIANCH]

ok, can you share some references which define philosophy of this type of applications.
Regards

 

[georgeverghese]

You may need a dedicated KOD for the LP FG system if there are more than 1 engines runnning at this level. The reason being you need a control buffer volume to absorb the shock of a single engine tripping out. The LP FG KOD will then "absorb" the shock of the consequent pressure rise in the LP fuel gas system without it tripping on high high pressure, and hence the other engine can run without losing fuel gas. This is not possible with the HP KOD.