IMPROVEMENTS IN OR CONNECTED WITH SAFETY VALVES FOR BOILERS OR WATER HEATERS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by William Payne and William Fisher
at the Office of the Commissioners of Patents on the 2nd June 1881.
WILLIAM PAYNE, of Birmingham, in the County of Warwick, and WILLIAM
FISHER, of Tipton, in the County of Stafford. "IMPROVEMENTS IN OR CONNECTED
WITH SAFETY VALVES FOR BOILERS OR WATER HEATERS."
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Our Invention consists of the construction and arrangement of parts hereinafter
described as Improvements in or connected with Safety Valves for Boilers or
Water Heaters."
A casing in the form of the capital letter Y and hollow, carries an ordinary
safety valve and seat at the top of each of its arms. One of these valves is pressed
down by a coiled spring above it in a well known manner, and the other one by
a dead weight. Attached to the framing, which carries in the one case the spring,
and in the other the dead weight, is a lover of the first order. These levers are
arranged so that they meet and are connected together over the central part of the
casing in such a manner that any excess of pressure under either of the valves
will tend to lift, not itself only but also the other.
.
COMBINED FLOAT, WATER LEVEL INDICATOR, AND SAFETY VALVE.
A vertical pipe is attached to the boiler or other vessel under fluid pressure; at
the top of this pipe is a safoty valve and seating, tho valve is pressed to its seat
by a weight on a lever in the usual manner, but this lever is prolonged beyond its
fulcrum in a direction away from the weight, and at the end farthest from the
weight is attached a suspended bridle, so arranged as to be actuated by a float in
the following manner :-
An ordinary boiler float and standard carrying a wheel is provided. Over this
wheel passes a chain which has a counterweight at one end, and at the other is
fastened to the rod which, passing through a stuffing box, is attached to a float in
the boiler in a well known manner. The wheel has a projecting finger, and its
action is as follows:-When the water in the boiler is at its proper level, the
ID 31

page_text: pointer on the wheel is in a vertical position and indicates safety; if however the
water falls too low then the wheel partly revolves by the action of the float and
chain, and the projecting finger engages in the bridle above mentioned, and thereby
opens the safety valve, allowing the steam to escape, the lower the water level
falls the wider up to a determined limit is the safety valve opened.
COMBINED SAFETY VALVES FLOAT AND BELL WEIGHT.
In the combined safety valves with float and bell weight there is a vertical pipo
attached to the boiler and carrying at its upper end the main safety valve. This
valvo is held down by a lever and weight, but instead of the weight being of the
ordinary construction, it is somewhat of the form of a bell, that is to say, it is
cylindrical and closed at the upper end. The lower or open edge dips into a
vessel containing water after the manner of a diving bell or gas holder. This
vessel which contains the water is by preference of a cylindrical form, standing
with its axis vertical, and the upper end is closed, but has an opening through
which the suspending rod of the bell weight passes. Attached to the side of this
upright cylindrical vessel is a small safety valve which may be actuated simply by
the pressure of the steam, in which case the steam is allowed by the opening of
the small valve to pass through a pipe into the cavity of the bell weight, which it
will then raise, and by so doing will open the main safety valve and allow the
steam to escape.
Or the small safety valve may be actuated by combination with a float, so that
when the water level in the boiler sinks too low the small safety valve will be
opened by means of the chain passing over the wheel on the ordinary float standard;
and then the valve being opened the steam will rush under and raise tho.bell
weight in the manner previously described, raising the main safety valve and
allowing the steam to escape.
In a combined self acting damper and safety valve there is a vertical cylindrical
casing closed at the bottom and containing water to nearly half its depth. This is
provided with a cylindrical bell weight having its lower edge dipping into the
water. A chain from the top of this bell weight passes over a pulley attached to
the vertical casing and is attached to the damper.
A pipe in connection with the boiler rises inside the bell weight. The action is
as follows:-When the pressure of the steam rises beyond the proper height it
lifts the bell weight and closes, or partially closes the damper, thus reducing the
draught and the production of steam. The attachment to the damper may also be
made so that the same movement which closes the damper may open a safety
valve. The safety valve of ordinary construction may be applied to eontrol the
admission of steam under the bell weight permitting it to rush under and thus
to close the damper when the pressure rises so high as to overcome the resistance
of tho weight with which the valve is loaded.