A. Close the feed valves; the water valve may leak.
90. Q. How can you tell if equalizer tubes become stopped up or broken?
A. If they were stopped up the equalization would be destroyed, and when the steam-chest pressure was less than the boiler pressure the feed would work too fast, the oil would enter the feed glass in a stream instead of forming into drops. If they were broken, the lubricator could not be used. The auxiliary oilers would have to be used to lubricate the cylinders.
AIR BRAKE QUESTIONS
1. Q. Explain how an air compressor should be started.
A. A compressor should be started slowly, with the drain cocks open to allow the water of condensation to escape; and as no provision is made in the steam end to cushion the pistons at the end of their stroke, it should be allowed to work slowly until a pressure of thirty or forty pounds has accumulated in the main reservoir; the piston, having to work against this pressure, will be cushioned at the end of each stroke. After the compressor is warm, the drain cocks should be closed and the throttle opened sufficiently to run the compressor at the proper speed. The lubricator should then be started and allowed to feed freely until eight or ten drops have passed, when the feed should be reduced to an amount sufficient for proper lubrication.
2. Q. What kind of oil should be used to lubricate both the steam and air cylinders of the compressor?
A. Valve oil.