Orifices in Steam Generators.
Year: 1886

page_text: Orifices in Steam Generators.
I, CHARLES ALBERT KNIGHT, of the Babcock and Wilcox Company, 107 Hope
Street, in the City of Glasgow, Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:
As heretofore constructed and fitted the cover provided for each hand hole seat
in the headers or manifolds and other parts of sectional steam generators, such as
those of the well known Babcock & Wilcox type, has usually consisted of a saucer-
shaped cap bearing upon the seat and secured in contact therewith by means of a
clamp inside in conjunction with a screw bolt: passing through the cap and fitted
with a screw nut outside. With the object of lessening the cost of construction
and the time and labour consumed in fitting such header caps in place, also of
ensuring accuracy of fitting and of avoiding leakage which may take place at the
joint between the cap and nut, my invention consists in forming the cap and nut
in one piece, tapping or screwing a hole in the cap but not quite through it, and
securing the cap in place by turning it on the screw bolt until the face of the cap
grinds in and bears closely against the seat formed around the hand hole or other
orifice, the cap being guided therein by an inwardly projecting rim which serves
the purpose of bringing the parts into the proper engaging position. My invention
further consists in forming a safety clamp, for use in conjunction with such a cap,
in the shape of a disc of dished formation and of greater diameter than the orifice
Bo as to provide a suitable bearing against the metal surrounding it but having its
edges flattened or grooved on opposite sides to admit of its passage through the
orifice, the object of this formation of the clamp being first to confine the outflow
of the water or steam to small jets or streams at the points where the clamp does
not completely close the orifice instead of permitting of the discharge in one large
volume in the event of the securing bolt giving way, and second to obtain a freer
waterway within the header by reason of the clamp and bolt-head being carried to
a large extent within the orifice.
In the accompanying drawings my invention is represented as applied to the
band hole seats in the header of a sectional steam generator, fig. 1 being a front
elevation and fig. 2 a sectional elevation of the front of the header showing the

page_text: caps and clamps in section and in elevation and fig. 3 an elevation of the improved
clamp alone.
The cap A, has formed upon its outer face a projecting boss A¹, of polygonal
form as seen in plan, corresponding to the screw nut which with the ordinary cap
serves to secure the cap in place but differing therefrom in so far that under my
invention the nut instead of being a separate part is formed integral with the cap.
A hole a, is truly bored and tapped into the cap and boss, as seen in fig. 2, for the
reception of the holding bolt B, whose head is retained by a clamp C, which may
be of the ordinary form, as shown at the upper part of fig. 2, but is by preference
of the formation represented in fig. 3 and at the lower part of fig. 2.
A guiding rib a¹ is formed on the cap to guide it into the hand-hole D, of the
header E, and a bearing seat which may be truly turned flat, as shown, or conical
to correspond to the formation of the band hole seat d, is formed on the cap which
forms more readily a close steam and water-tight joint, when by turning it with
the aid of a wrench applied to the polygonal or paned part A, upon the screw
bolt B, the cap is brought to bear upon its seat. The safety clamp C, is made in
the form of a disc having segments shorn off it at C¹, in order to permit of its
passage through the orifice D, which it almost wholly closes when fitted in place
as shown in figure 2. The clamp is of dished formation in the example illustrated
and has a suitable seat d' formed at its edge to suit the bearing round the orifice D,
and a central recess, to receive the head of the bolt B, and when fitted in place
it offers a minimum obstruction to the circulation of the water and steam in the
header.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
.1. A cap or cover for hand holes or similar orifices having a polygonal nut or
paned boss formed integral therewith and a hole tapped therein for the reception
of a holding bolt, substantially as herein described with reference to the drawings
annexed!
2. In conjunction with a cap or cover for a hand hole, sludge hole or similar
orifice in a steam generator the safety clamp C formed substantially as described.
3. The combined cap and nut A. A¹ in combination with the safety clamp C C¹
and holding bolt B as and for the purpose set forth.
m
7000