from The Century Dictionary and Cyclopedia
- n. The finished contact area upon which the lifting-valve rests when closed, and the sliding-valve slides to open and close the ports. In lifting-valves it is usually annular, and either flat or conical in form.
- n. In machinery, the surface upon which a valve rests.
Sorry, no etymologies found.
When a weak current of electricity is caused to circulate round the coils of the electro-magnet N, the small armature disc J is drawn off the valve-seat H on to the zinc plate K.
The valve-seat H has formed on its lower surface two crescent shaped long and narrow slits.
It is, therefore, always very close to the poles of the magnet, consequently a very faint impulse of electricity will suffice (aided by gravity) to draw the disc off the valve-seat H.
If you are carrying 90 pounds of steam you have about 320 degrees of heat in your cylinder, with I20 to I25 pounds you will have about 350 degrees of heat, and in order to lubricate your valve and valve-seat, and also the cylinder surface, you must use an oil, that will not only stand this heat but considerable more so that it will have some staying qualities.
There do not seem to be any reports of valve-seat recession from unleaded mogas users or the IO-540s which are certified for operation on ethanol in Brazil.