Hello Yutaka,
1.  The changes you have made to the HPS ( longer inlet pipes) are not a
final fix of the HPS problems.  Before the new pipes,  we filled the oil
level in the HPS so full that even though the other pipes were short,
they did not cause an air problem.  In other words, the change installed
so far has only been a fix so that the oil can be lower for the fire
department.  The air is no better than when we had the oil higher.  In
fact, the air problem probably is worse now because the oil time in the
tank is shorter so less air comes out.
2.  Screens to put in the HPS tank are on their way to Japan.  They will
help remove air from the oil when the oil circulates through the HPS
tank.
3.  For now, Please try on Y3 actuator (closest one to Z3) to turn the
pilot pressure hose downward at the manifold on the wall.  ( You will
have to loosen the manifold on the wall and rotate it). This pilot
pressure hose now connects to the manifold on the wall pointing slightly
upward (I turned it up when I was on site to try get rid of air faster).
Turning it down may help because air in the pilot pipe on the wall is
probably at the top of the pipe.
4.  I do think some of the air problem comes from the pilot pressure
pipe.  I had Jim get new parts and they are being sent to Japan.  These
parts will allow the pilot pressure lines to the actuators to be on the
bottom. (the manifolds on the wall will all need to be loosened and
turned so the outlets point down.)  Also, a new end plug for the pilot
pressure pipe with a hole for mounting a hose with a small valve that
outlets into the drain line can be installed.  This new hose, with the
valve opened just a little, will allow the air to go out of the pilot
pressure line on the wall and into the drain line.  Now all air in the
pilot pressure line must go through the Y3 actuator's pilot servovalve.
5.  Monday I will try find out when these new parts will arrive in
Japan.
6.  Please assure the customer that we intend to get this problem fixed.

Thank You-  Omar 

> -----Original Message-----
> From:	Otsuka, Yutaka 
> Sent:	Friday, April 10, 1998 9:44 AM
> To:	Larson, Rod
> Cc:	Rood, Omar
> Subject:	NTT  Y2 Actuator
> Importance:	High
> 
> Hello Rod-san,
> 
> How are you doing? After modify the HPS, the Y2 actuator(closest to
> Z3) squeaky sound has occured(move the actuator round 1Hz),after bring
> up the High pressure.
> But it has gone,when we did random. (But it happens all the time now)
> So I checked both 469D program. These were nothing wrong. I changed
> Valve driver, but it was OK.
> I wanted to change the ServoValve,but we don't have any spare for
> that. Custmer still don't know it happen all the time. 
> I really wondered, we modifyed the HPS. It seems getting worth. (It's
> about 80gal maximum) Please help!!
> 
> Best RGDS,
> Yutaka 
