IMPROVEMENTS IN THE CONSTRUCTION OF HYDRAULIC VALVES FOR CONTROLLING GAS AND FLUIDS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Henry Nathan Maynard at the Office
of the Commissioners of Patents on the 19th December 1879.
HENRY NATHAN MAYNARD, of No. 7, Westminster Chambers, Westminster,
London, Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF HYDRAULIC VALVES
FOR CONTROLLING GAS AND FLUIDS."
1st. This Invention relates to improvements in the construction of valves to be
used for controlling gas and fluids whereby the gas or fluid may be completely
shut off or controlled by passing through an adjustable hydraulic seal, thereby
greatly reducing the cost of manufacture and fitting of large valves.
"
2nd. Valves constructed according to my improvements take the place of what
are called "syphons' or receptacles for draining any liquid into that may
accumulate in gas pipes, from which receptacle this surplus liquid may be extracted
in the ordinary way.
3rd. The third part of my improvements consists of so constructing the improved
valves as to make them take the place either wholly or partially of the hydraulic
main in connexion with gas retorts, giving the stoker by means of a simple move-
ment of a handle, whereby the amount of seal is adjustable, the power to control
the pressure inside the retorts at each varying period of a charge of the retort.
Where a series of valves are required they may be made to form such series by
uniting several together.
I construct a valve made either of cast iron or other suitable metal or material
in the manner following, that is to say:-
I make a gas tight chamber with an inlet and an outlet, a diaphragm or partial
division in this chamber extending from the top somewhat more than half way
down, separating the inlet from the outlet, with a supply of water or other liquid in
the bottom of the chamber, which liquid is to either open, close, or regulate the
seal of the valve.
This closing or regulating the seal I effect by means of a moveable watertight
displacement block or box, either rectangular or otherwise, of sufficient cubic
contents, which on being lowered into the liquid and displacing it causes the liquid
to rise above the bottom of the diaphragm high enough to overcome the pressure or
vacuum of the gas, or only to raise the liquid a certain height, which can be
regulated at will by either more or less immersion of the displacement block,
whereby the gas can pass through the liquid when the pressure or vacuum exceeds
that of the seal between the bottom of the diaphragm and the surface of the
liquid.

page_text: On raising the displacement block out of the liquid the liquid returns to its
normal level at the bottom of the chamber to a certain distance below the bottom
of the diaphragm, thereby allowing a free passage for the gas, and thus opening the
valve or passage for gas. I make use of the valve as a syphon by utilizing the
drainage of the pipes connected to the valve as the sealing liquid, and keep this t
liquid at a proper level when the valve is open by means of a suction tube of proper
length, to which an ordinary syphon pump can be attached and the surplus liquid
pumped out. To keep the liquid at a proper level when the displacement block is
down and the valve closed I make use of a shorter suction tube of proper length,
to which an ordinary syphon pump can be attached and the surplus liquid 1
pumped out.
I make provision for the overflow of liquid caused by condensation, such, for
instance, as tar in gas making, by means of an adjustable overflow bend, which is
worked by a lever attachment simultaneously and oppositely to the displacement
block, so that as the displacement block is lowered the overflow bend rises, and 1
vice versa, thereby retaining the liquid inside the chamber at the level caused by
the immersion or otherwise of the displacement block, and only allowing the liquid
to overflow at the level of the top of the overflow bend.