M20 Turbos Pressure relief valve

[tmo]

10 hours ago, N201MKTurbo said:

It has an Android in it so it opens at an absolute pressure

Imagine getting anything running Android certified ;-)

(yes, I know, autocorrect, aneroid is probably too odd of a word for it)

 

[N201MKTurbo]

46 minutes ago, tmo said:

Imagine getting anything running Android certified ;-)

(yes, I know, autocorrect, aneroid is probably too odd of a word for it)

 

 

46 minutes ago, tmo said:

Imagine getting anything running Android certified ;-)

(yes, I know, autocorrect, aneroid is probably too odd of a word for it)

 

Crap, I fixed that twice and it got through anyway. My IPad must have a thing for Android.

[N231BN]

12 hours ago, N201MKTurbo said:

The function of this valve is different than a normal turbo system. It controls the upper deck pressure. It is what makes this system so stable.

It looks like a normal pop off valve, but it is actually an absolute pressure controller. It has an Android in it so it opens at an absolute pressure. A regular pop off valve opens at a gauge pressure.

Rich,

All "pop-off" valves are absolute pressure controllers, it makes no sense to design them any other way. However, I seriously doubt they intended it to be the primary regulator in a turbo system. It would be a very inefficient way to accomplish that as you are wasting a lot the energy used to spin the turbo.

I obviously don't own one of those systems so I could be wrong on that but it doesn't sound right to me.

Respectfully,

[N201MKTurbo]

19 minutes ago, N231BN said:

Rich,

All "pop-off" valves are absolute pressure controllers, it makes no sense to design them any other way. However, I seriously doubt they intended it to be the primary regulator in a turbo system. It would be a very inefficient way to accomplish that as you are wasting a lot the energy used to spin the turbo.

I obviously don't own one of those systems so I could be wrong on that but it doesn't sound right to me.

Respectfully,

That is exactly how this system works. Yes, it blows a lot of air overboard. The setting of the fixed waste gate determines how much air gets blown overboard. 

As far as I know, this is the only turbo system that works this way. The up side is, it is very stable. You can set a MP and mixture and descend from the flight levels without touching a thing. 

[N231BN]

30 minutes ago, N201MKTurbo said:

That is exactly how this system works. Yes, it blows a lot of air overboard. The setting of the fixed waste gate determines how much air gets blown overboard. 

As far as I know, this is the only turbo system that works this way. The up side is, it is very stable. You can set a MP and mixture and descend from the flight levels without touching a thing. 

That is interesting, does it have a reference line attached to the aneroid?

[M20F-1968]

On 9/9/2021 at 9:33 PM, N201MKTurbo said:

The function of this valve is different than a normal turbo system. It controls the upper deck pressure. It is what makes this system so stable.

It looks like a normal pop off valve, but it is actually an absolute pressure controller. It has an Android in it so it opens at an absolute pressure. A regular pop off valve opens at a gauge pressure.

Can you explain you answer more fully and provide specifications and/or part numbers.  I have a pressure relief valve and it apparently fits the requirements of the STC.  Please provide more information so I can understand the difference you are pointing out.  Thanks.

[N201MKTurbo]

2 minutes ago, M20F-1968 said:

Can you explain you answer more fully and provide specifications and/or part numbers.  I have a pressure relief valve and it apparently fits the requirements of the STC.  Please provide more information so I can understand the difference you are pointing out.  Thanks.

John,

We have different STCs. The part number of the valve in question is stated above. Your pressure relief valve is just to protect the turbo in case you close the throttle quickly.

[DaveM]

Aero Recip repaired this 470930-9018. Almost new with a new housing, bellows, springs. $800 Canadian peso's. Installed, seems to work like a charm. sea level T/O reported 17 gph with throttle set for 30" and 2700 rpm. Valve is set for 32.5". Interesting note is that the valve is good for 5" of dump. Means that if you run it to 37.5" of turbo output, it will hold the 32.5" manifold. If turbo output climbs above the 37.5", so will your manifold pressure. Don't think anyone wants to go there.