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Re: REFLECTOR: sequence valve location
From: Dave Black <firstname.lastname@example.org>
> The "trick" to eliminating nose door slamming is to locate the sequence valve
> as near to a linkage pivot point as possible. It takes an awful lot of force
> to depress this valve, so the more leverage you can get, the better.
That's the real solution, though leverage isn't the only problem.
I didn't particulary like the sequence valve inside the console, (With my big
hands, installation and adjustment would be a nightmare.) so I mounted it on
the front of the canard bulkhead so the gear would press the control. It
worked, after a fasion. While everyone else was getting a big *SLAM* as the
doors closed, I got a *SLAM-SLAM-SLAM*. It sounded like a M-16 doing a
three round burst.
What was happening was as the valve depressed, pressure was released
into the door cylinders, whacking them up a notch, and the gear would drop
slightly from the loss of pressure, closing the sequence valve. Then the
pressure would build again and the cycle would repeat. A bed of silicone for
the gear to rest in helped, (Reducing bounce from the top of travel.) but the
final solution was a one-way restrictor valve so the door cylinders wouldn't
see a burst of high pressure fluid.
Of course, now the retriction is too great and the pump pressure builds to
cutoff before the doors are fully closed. Then, as is the pressure bleeds down
for a two count, the pump comes on again and everything closes like it
The important part is to have the valve placed where relative movement is
small. That way, changes in line pressure as the valve opens doesn't cause
large variations in the opening of the valve. It also opens the valve in finer
degrees so the door cylinders don't get a sudden burst of high pressure fluid.