servo controlled ball valve?
 

Hi,

I'm installing my equipment in the Roo and have a question. In some early versions of JET International I saw they used a servo controlled ball-valve as a kill switch. I'm using the jet-cat, but is it still necessary to install such a servo controlled kill switch?
Most pictures of installation I see posted don't include such a switch.

Rgds,

Adryan

RE: servo controlled ball valve?
 

Good question, I am looking for the same thing.

Found this in the festo catalogue which looks as if it might have a long enough arm
for a servo connection, but it only comes in 4mm fitting, I need 3mm.


http://catalog.festo.com/data/CAT_PD...04/4_08-12.pdf

RE: servo controlled ball valve?
 

Hi Adryan,

In England, the BMFA uses the GTBAs Code of Practice as the authoritive document, and it states:

"3.3 The fuel line must have a mechanical shut-off valve, in the delivery line from the fuel tank(s), or a switch to isolate the electrical supply to the fuel pump motor, which can be manually operated in addition to any servo control, and which is readily accessible."

Cheers,

Dick
England

RE: servo controlled ball valve?
 

so which one do you use Dick?

RE: servo controlled ball valve?
 

Just the standard manual shut-off valve that UKFLIER has highlighted....not servo controlled (it's a back-up just in case the electronic side of things fails - also useful to stop fuel going to the engine during refuelling, etc).

Do a search for Festo and, from there, find where the nearest distributer is to you...or, if you're in the UK, go to Motors and Rotors website and buy one from Dave Wilshere - he stocks them.

Cheers,
Dick
England

RE: servo controlled ball valve?
 

If you ar not too restricted on space you can put a Festo 4mm/3mm straight reducer connector either side of the 4mm ball valve.

Rob.

RE: servo controlled ball valve?
 

I think it would be very wise to add a servo to the manual valve to have the capability of shutting off the fuel flow to the pump. I have seen an ECU malfunction in the air, the fuel pump continued to run and the results were not a pretty site. The servo could be mixed with the throttle trim so that when you shut down the ECU the servo also closes the fuel valve. David Gladwin outlined this in one of the Jet International Articles. He used a cable that can only close the valve. The valve had to manually reopened.

I think this is a real smart thing to do...could possibly save an airplane.

RE: servo controlled ball valve?
 

This is what I use as a manual/servo controlled bypass valve in all my airplanes. It is what Simjet recommended for use in the old pre-electonic fuel valve systems.

Chris

RE: servo controlled ball valve?
 

Cairoman, I'd love to get some of those valves. Do you know of a source? Thanks.

RE: servo controlled ball valve?
 

Hi Mark,

It's a Festo three-way valve, Type:33003 KH/O-3-PK-3 for 0-115 psi. I bought a bundle of those, four years ago in Toronto from Festo Canada.

Chris

RE: servo controlled ball valve?
 

Chris that is brilliant, Just what I was looking for as well.

John

RE: servo controlled ball valve?
 

Hi John,

Glad, I could contribute with something here. Please note that these valves do not last too long. I change mine once a year. The good thing about those, is that they will not put stress on the pump, just by-pass the fuel supply.

Chris

RE: servo controlled ball valve?
 

Why don't they last long? What craps out? Thanks.

RE: servo controlled ball valve?
 

The rubber stoppers inside them become hard after prolonged exposure to our fuels (turbine oil).

Chris

RE: servo controlled ball valve?
 

Guy's

MAS make a nice servo operated shut-off valve that's small and neat.

The Festo ball valve can be servo opertated with a cam arm-Tom Wilkinson showed one in his original Kangeroo review in RCJI

Dave Wilshere