Originally Posted by
Gin Jockey
the FCOM makes no mention of it.
Both iPad apps for 737 I have mention it (737 cockpit companion and 737 MRG)
“spar valve mounted on the front spar outboard of each strut
- access is through an access panel on the leading edge
- has backup nicad battery to make sure it always has power to close
- the fuel spar valve actuator is interchangeable with the crossfeed valve actuator”
“a dedicated fuel spar valve battery ensures electrical power to close the valves should the hot battery bus become unpowered”
I’ll ask an engineer when I am at work tomorrow.
What you quoted seems quite clear. If it's in a system description or training material that came directly or indirectly from Boeing, then I think you can assume it's accurate. I just don't remember seeing reference to a dedicated battery for the spar valve in the engineering documents covering the fuel system description, the rotorburst safety analysis, or powerplant fire safety. Learned something new today. Thanks.