United States or Hong Kong ? Vote for the TOP Country of the Week !
Then, with the valves closed, adjust each valve-stem to give 1/32 of an inch clearance at the point of closing of the pawls when they are "in," securely locking the check-nut as each valve is set. Repeat this operation on the other side of the machine and we are ready to adjust the governor-rods.
Let the wheel rest on the tire with valve down; loosen all the lugs; insert thin edge of spring-leaf between rim and tire, breaking the cement and partially freeing tire; insert spring-leaf farther at a point just about opposite valve and pry tire free from rim, holding and working it free by pushing in other irons or screw-drivers, or whatever you have handy; when lugs and tire are out of the hollow of the rim for a distance of eighteen or twenty inches, it will be easy to pass the iron underneath the tire, prying up the tire until it slips over the rim, when with the hands it can be pulled off entirely; the wheel is then raised and the valve-stem carefully drawn out.
If hot cement is used it will be necessary to heat the rim after the tire is on to make a good job. After the rim is prepared, insert valve-stem and the lugs near it; let the wheel down so as to rest on that part of the tire, then with the iron work the tire into the rim, beginning at each side of valve.
Stopping the turbine is practically the reverse of starting, the successive steps being as follows: starting the auxiliary oil pump, freeing it of water and allowing it to run slowly; removing the load gradually; breaking the vacuum when the load is almost zero, shutting off the condenser injection and taking care that the steam exhausts freely into the atmosphere; shutting off the gland water when the load and vacuum are off; pulling the automatic stop to trip the valve and shut off steam and, as the speed of the turbine decreases, speeding up the auxiliary oil pump to maintain pressure on the bearings; then, when the turbine has stopped, shutting down the auxiliary oil pump, turning off the cooling water, opening the steam chest drains and slightly oiling the oil inlet valve-stem.
If screwed out too far, the valve-stem becomes too long and the pawl in descending will, after the valve is seated, continue downward until it has broken something. If screwed in, the cross-head will be too low for the upper pawl to engage and the valve will not be opened. This second condition is not dangerous, but should be corrected.
All this can be done with the wheel jacked up, but if resting on the tire as suggested, the valve-stem is protected during the efforts to loosen tire. To put on a single-tube tire properly, the rim should be thoroughly cleaned with gasoline, and the new tire put on with shellac or cement, or with simply the lugs to hold.
Word Of The Day