Wren 44 TurboProp Users Manual. Copyright Wren Turbines Ltd February 2008 Page 13
Off-Board Propane
Many fliers prefer to have off-board propane supply and in this case, simply pipe the quick release fitting
directly to the propane valve. The quick release connector and pipework is supplied to enable either
arrangement to be achieved.
Canister valve
A canister valve is also supplied to screw onto your propane canister.
Traditionally this has only fitted canisters available in Europe but these are
now becoming common in the USA. This simple valve operates by
pressing the small sealing ball off its seat in the neck of the canister.
Control is attained by how far the ball is moved. The control works as a
normal tap, ie to turn on the propane turn the screw cap anticlockwise in
the “+” direction, to turn off rotate clockwise in the “-“ direction. It is not
necessary or desirable to move the cap more than about three or four
turns as the cap can be undone totally until it falls out – potentially
allowing a propane escape.
Warning
Whatever system you adopt it is very important not to allow liquid propane to reach the engine. This can
cause flaming and aggressive starting and can damage the engine.
Secondly
It is most important to remember that propane is highly flammable at all normal temperatures. Please be
very careful during filling or purging to keep everything away from sources of ignition.
Thirdly
Also remember that at high ambient temperatures pure propane can attain very high pressures that can
cause pipes to blow off their connectors. If it is deemed there is any possibility of this happening or if you
experience this, then switch to external plug-in propane which reduces significantly the possibility of large
propane release inside the aircraft.
SAFETY NOTES
We make no apologies for positioning these notes early in the manual. Please read the following
for your own safety and those around you - thank-you.
This engine is not a toy and can cause bodily harm to you or others if misused.
It is your responsibility as owner, to ensure safe, careful and considerate operation of your engine
at all times, and in accordance with the manufacturers instructions.
If you sell or give away this engine, please pass these instructions to the new owner.
This engine
must
only be run firmly attached to a secure and sturdy engine test stand or model
installation. The thrust is very considerable for such a small size and mountings must be sufficient
to withstand such forces. Use appropriate screws and proper captive nuts. The engine must
never be run held in the hand or clamped in a vice.
This engine is an internal combustion gas turbine engine which generates large quantities of heat
– ensure the mountings and installation are appropriate for operation at these elevated
temperatures.
During operation and for a time afterwards there are parts of the engine which are hot enough to
cause serious burns – do not touch any part of the engine until it has cooled to room temperature.
Always operate your engine in open air away from confined spaces as the engine exhaust
contains gases which can cause asphyxiation and nuisance from smells.
