Its use is to show the amount of back pressure, and in a condensing engine to show the degree of vacuum obtained.
But the back pressure of the cat's body overloaded the discharge circuits.
The back pressure saved will at once show in the pulling power of the engine, and every one will be surprised.
There is then no back pressure on the exhaust steam, theoretically.
So in using steam expansively the back pressure must be at a minimum, and this is especially true in the compound engine.
He opened the muffler so as to get rid of all back pressure, and opened the throttle to its widest extent.
The problem now is to get rid of that back pressure, and the old type engines give a hint how it may be done.
As Bert had already explained to Dick, this was done to eliminate any back pressure from the exhaust gases.
There is no back pressure of blood here, so that the movement of fluid through the lymphatics is not hindered.
The line from d to e is therefore the exhaust line, and that from e to a is the back pressure line or counter pressure line.
back pressure n.
Pressure exerted upstream in the circulation as a result of obstruction to forward flow, as when congestion in the pulmonary circulation results from failure of the left ventricle.