The engineer's sketch-book of mechanical movements, devices, appliances, contrivances and details employed in the design and construction of machinery for every purpose

by Thomas Walter Barber

[1637]. A modification of the last named.

[1638]. Pass valve, used for pneumatic despatch tubes.

[1639]. Oscillating lever duplex valve.

[1640]. Simple radial disc valve or sluice.

[1641] & [1642]. Oscillating cylindrical valves. Corliss valves; sometimes made tapered or conical.

[1643]. Multiple ball valve, for high lift delivery valve of large pumping engines. Balls are of guttapercha, and open and close without shock.

[1644]. Multiple ring valve. The rings open and close in succession, thus avoiding shocks.

[1645]. Double beat ring valve.

[1646]. Double beat equilibrium or Cornish valve. The upper seating can be made of such area as to partly or entirely balance the valve.

[1647]. Multiple ring valve. The indiarubber rings expand and contract over the perforations.