A good practice during firing up is to open the throttle and the drip valve. Once the burner is burning kerosene, the burner valve should be opened a small amount (perhaps one-quarter to one-third of a turn of the valve wheel) so that the burner doesn’t fire at maximum heat. While this means the firing up process takes longer, it is better for the car since the boiler and the superheater are not subjected to extreme heat but rather are heated gradually. From when the car was shut down there will no doubt be water condensed in the superheater which will turn to steam and vent out the drip valve.

Once the water of the boiler starts boiling the generated steam will be released through the throttle. The steam will blow any water in the engine steam lines back to the engine and out the drip valve at the bottom of the valve chest. At this point the burner valve can be opened fully and the burner fired at its maximum rate. The steam running through the superheater acts to cool the superheater and thus protects the superheater from damage.

The steam flow has the added benefit that it serves to heat the engine valve chest and cylinders as it exits the drip valve under the engine. To protect the superheater keep a small amount of steam passing through the line, which is enough moisture to protect the superheater. As the burner heats the boiler and steam generation increases, the throttle will need to be closed to only allow a low rate of steam flow from the drip valve. Steam pressure will increase and as it does the throttle will need to be continually adjusted to close down the steam flow. Proper steam flow through the drip should be such that the exiting steam just hits the pavement under the car rather than floods the pavement under the car with an inverted mushroom cloud of steam.  Shown at the left is a 1908 Model K Stanley being fired up.  The steam flow cascading from the drip is nominal for keeping the superheater properly cooled and for preheating the engine casting.

The second and perhaps most important use of the cylinder drain valve is to provide a means for water to escape from the steam lines and engine valve chest when starting the car out from rest. When the car is stopped there will be some residual steam in the piping past the throttle. Anytime the car sits idle for a short period of time this steam will condense back to water. Additionally if the throttle leaks, the steam will flow into the superheater and piping to the engine. With the burner off these pipes eventually cool and the condensing water may eventually fill the superheater and engine steam piping with water. This water will collect in the superheater and piping to the engine.

When it is time to move the car again, opening the throttle will cause all this water will be blown back to the engine. If the drip valve is closed the water will be blown into the engine cylinders where clearances at either end of the piston stroke to the cylinder heads are tight. Too much water, which is non-compressible, and cylinder heads will be blown off and the piston shafts and crank arms can be bent. Opening the drip, along with always starting out slowly allows any accumulated water to exit the drip valve and not enter the cylinders. In fact a good practice especially when steaming up the car is to "rock" it back and forth. This relieves any water trapped in the engine cylinders. Rocking the car can be accomplished by moving 10 feet forward or so, stopping, then reversing back to the starting position. This should be done slowly where there is between 400 PSIG and 500 PSIG steam pressure and with the drip valve one-half turn open.