MENTS IN WATER GAUGES FOR STEAM BOILERS
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Joshua Rundell and William Joshua
Rundell at the Office of the Commissioners of Patents on the 18th November
1870.
JOSHUA RUNDELL and WILLIAM JOSHUA RUNDELL, of the Imperial Iron, Copper,
"IMPROVE-
and Brass Works, Poplar, in the County of Middlesex, Manufacturers.
MENTS IN WATER GAUGES FOR STEAM BOILERS.
Our Invention relates to water gauges for steam boilers. The ordinary water
gauge, consisting of a glass tube supported in metal fittings which are so fitted on
steam boilers as to communicate with the steam and water spaces of the same, is
now almost the only apparatus employed for this purpose. And long usage has
demonstrated its general efficiency and reliability under all circumstances when it
is properly made and fitted to the boiler, and when not exposed to blows or shocks,
or to very sudden changes of pressure or temperature. It has, however, from the
very nature of its construction one very important defect, namely, the liability of
the glass tube to fracture and the consequent severe scalding of the engine driver or
other person who may be near the boiler when this accident occurs.
Our Invenion is designed to remove this defect from water gauges, and thereby
greatly increase the value of these very useful adjuncts to a steam boiler. For
this purpose we provide the gauge with a valve which closes automatically when
the glass is broken.
In carrying our said Invention into practise we may provide the gauge with the
ordinary glass tubes, and the usual stuffing boxes for holding the same and keeping
it steam-tight; or we may apply our said Invention to those gauges which have a
flat piece of glass fitted into a metal frame, or to other modified forms of gauges.
We cast the said stuffing boxes or other devices for holding the indicating part of
the gauge with a neck, which is designed to be inserted through the boiler plate
and to be secured therein by screw nuts; this neck is closed at its inner end by a
perforated piece which admits the steam freely, and within this neck we enclose a
small ball valve. A seat for this valve is formed in the passage leading from the said
neck to the opposite end of the casting, and the said valve is made of such a size as
to roll freely between this seat and the perforated end of the neck. When this valve
is not on its seat there is free passage for the water or steam to the glass tube, and
this said valve remains in this position while the gauge is working.
In the aforesaid passage we fit a tubular spindle on which is formed a valve
whose seat is formed in the said passage outside of the stuffing box or socket in
Povice 2dl

page_text: which the glass tube is secured; this valve is provided for blowing off the water
or steam when necessary, a small nozzle arranged in an inclined position serving for
the discharge of the steam or water when this valve is opened. The said hollow
spindle is also provided with another valve which when closed cuts off the com-
munication between the boiler and the gauge. The valve spindle is made steam-
tight in the said passage by a suitable stuffing box, and is provided with a small
hand wheel or handle for opening and closing the said valves.
Through the said hollow spindle we pass a rod which extends to the seat of the
aforesaid ball valve. This rod is provided inside the casting with a small valve
which closes the inner end of the tubular spindle, and its outer end is provided with
a head or button outside of the said hand wheel, and under this head we place a
small spiral spring which tends to keep the said rod out of contact with or away
from the seat of the said ball valve.
It will be understood that the improvements above described are applied to both
the top and bottom fittings of the water gauge. If the glass portion of the gauge
should be fractured the said balls will be carried with the steam and water to their
seats and will immediately close the passages leading to the said glass portions of
the gauge, and the balls will be held by the internal pressure in this position until
released. The engine driver or other attendant can therefore without danger of
being scalded remove the broken tube or other glass portion and replace it by a
new one; then by pressing the heads or buttons of the aforesaid rods the balls
will be forced from their seats and the gauge will be restored to its working
condition.
Instead of the aforesaid spring rod for pushing the ball from its seat we in some
instances arrange a small valve or cock to admit steam to the outside of the ball
seat, or under the ball when on its seat, and thereby cause the said ball to leave its
seat. The aforesaid valve on the hollow spindle which serves for closing the
communication between the boiler and the gauge will be very serviceable in cases
where it is desired to close this communication under circumstances when the
automatic ball valve does not operate.