Improvements in Safety Valves for Hot Water Boilers.
Year: 1894

page_text: Date of Application, 21st Sept., 1894
Complete Specification Left, 21st June, 1895-Accepted, 17th Aug., 1895
PROVISIONAL SPECIFICATION.
Improvements in Safety Valves for Hot Water Boilers.
I, JAMES KEITH, Assoc. M. Inst. C.E. of 57 Holborn Viaduct, in the City of
London, Gas, Hydraulic, Heating and Ventilating Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention has for its object the provision of a safety valve for hot water
boilers such as are used in kitchen ranges and which shall not be liable to become
fast or incrusted by deposit of saline matter or sediment or to cant or jam, whilst
being adapted to open to discharge water upon the slightest increase of pressure
over that for which it is set.
The improved safety valve comprises a casing adapted for connection to the
water space of the boiler, the said casing being provided with a cup or trap
and having an annular valve seat formed in a part of the casing which is fitted
to dip into the trap. Resting on this seat is a valve preferably of elongated
conoidal or spherical form and hollowed out or formed with a cavity so that the
pressure of the spring or dead weight used to keep it closed is applied through
a rod or spindle bearing on the bottom of the cavity like a pivot and at a point
considerably under the level of the valve seat, and the valve thus adjusts itself
to its seat and cannot cant or jam. The valve rod or spindle is suitably guided
in or over the casing and is loaded either by weights or by a spring, the pressure
in the latter case being adjusted by a screwed cap or a screw and lock nut or like
means.
The trap or seal into which the valve seat dips is filled with glycerine, oil, pure
water or other liquid which will have no tendency to corrode, incrust or form
deposit on the valve and seat, and when the safety valve is connected to the boiler
an air space is left between the cup or trap and the boiler water. In that way the
saline or sediment depositing water circulating in the boiler and being used and
replenished is in large measure kept from actual contact with the valve and seat
unless when the required pressure is exceeded and the valve opens to discharge
part of the water which then overflows or is led off from the casing by an outlet
pipe connection.
In some cases as for example when the water used in the boiler is comparatively
pure the cup portion of the safety valve may be dispensed with, and in other cases
whilst the cup or trap is used the valve and seat instead of dipping into it may be
raised to a point considerably over it.
Dated this 20th day of September 1894.

page_text: Improvements in Safety Valves for Hot Water Boilers.
I, JAMES KEITH, Assoc. M. Inst. C.E., of 57 Holborn Viaduct, in the City of
London, Gas, Hydraulic, Heating and Ventilating 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 :-
This invention has for its object the provision of a safety valve for hot water
boilers such as are used in kitchen ranges and which shall not be liable to become
fast or incrusted by deposit of saline matter or sediment or to cant or jam, whilst
being adapted to open to discharge water upon the slightest increase of pressure
over that for which it is set.
The improved safety valve is illustrated by the accompanying drawings,
Figures 1 to 13 being vertical sections of several modifications, all of which are
constructed in accordance with my invention.
Referring to Figures 1 and 2, the improved safety valve comprises a casing A
adapted for connection to the water space of the boiler, a trap or liquid seal B and
an annular valve seat C formed in a part of the casing A and fitted to dip into the
trap B. The casing A is provided with a cup or trap B resting upon fins B¹
formed in the bell shaped end B2 of the connection from the boiler said cup being
held in position by fins A' on the lower part of the casing A which part is screwed
on to the bell-shaped connection B2, or the cup and casing can be formed in one
piece in like manner as shewn on Figures 5 and 6. Resting on the valve seat C is
a valve D preferably of elongated, conoidal or spherical form and hollowed out or
formed with a cavity E so that the pressure of the spring F (Figure 1) or dead
weight G (Figure 2) used to keep it closed is applied through a rod or spindle H
bearing on the bottom of the cavity E like a pivot and at a point considerably
under the level of the valve seat C, and the valve D thus adjusts itself to its
seat C and cannot cant or jam. The valve rod or spindle H is or may be suitably
guided in or over the casing A and is loaded as already described either by weights
or by a spring, the pressure in the latter case being adjusted by a screwed cap I or
a screw and lock nut or like means.
In
The trap or seal B into which the valve seat C dips is filled with glycerine, oil,
pure water or other liquid which will have no tendency to corrode, incrust or form
deposit on the valve D and seat C, and when the safety valve is connected to the
boiler an air space b is left between the cup or trap B and the boiler water.
that way the saline or sediment depositing water circulating in the boiler and being
used and replenished is in large measure kept from actual contact with the valve D
and seat C unless when the required pressure is exceeded and the valve D to
discharge part of the water which then overflows or is led off from the casing by
an outlet pipe connection J.
opens
In some cases as for example when the water used in the boiler is comparatively
pure the cup portion B of the safety valve may be dispensed with. A safety valve
so constructed is illustrated at Figure 3. Figure 4 shews the same form of valve
with a trap attached to it. In Figures 3 and 4 the valve D is held normally upon
its seat E by a tension spring K, the upper portion of which is laid in a slit in the
top of the valve spindle H, the lower end being held between a flanged sleeve L
surrounding the valve spindle H and screwed into the casing A, and an annular
groove formed in a ring M, said ring being held down by a cap I also screwed into
the casing A. A shield H¹ is placed between the spindle H and the tension
spring K in order to protect said spring from the action of the water.
Figure 5 shews a safety valve of the same form as that shewn by Figure 4 but
adapted for being placed within the boiler space as shewn and Figure 6 is a

page_text: modification of the same whereby access can be had to the working parts without
removing the whole valve and without allowing of any possibility of the confined
and separating air escaping from the air space b by any carelessness in forming
the joint above it. The shield H' in Figures 5 and 6 has openings h cut in it in
order to permit the water to pass through to the outlet J, as shewn by the arrows.
Figure 7 shews the valve spindle H guided through a sleeve H said spindle-
having a flared piece H2 secured on its upper end on which piece H³, a second
sleeve H³ carrying the dead weight G rests, and Fig. 8 shews a modification of
same in which the valve is screwed into the sleeve H³ and rests upon a seat C
carried up within said sleeve, the weight in this latter case being considerably
below the valve D and its seat C.
Figure 9 shews a safety valve of the same form as that shewn by Fig. 8
excepting that the sleeve H³ dips into a cup B³ surrounding the trap B, and Fig. 10
represents a similar form of safety valve, the valve D in this case being kept upon
its seat C by a compression spring F instead of as in Fig. 9 by a dead weight. In
this case the spring F is situated between an annular cup-like flange F¹ formed on
the sleeve H3 and a U-shaped ring F2 against which a cover or cap A' surrounding
the sleeve H³ and screwed into the casing A bears.
In Fig. 11 the trap B is carried up together with the valve seat C the valve D
which is formed on the inner side of a cover D' being kept on its seat C by the
action of a loaded dead weight G secured on said cover D' and hanging con-
siderably below the valve seat. Fig. 12 is somewhat similar to Fig. 11 the valve
being loaded in this case by means of a spring F acting between the upper side of
the valve D and a cup D² on which bears a cover A' surrounding the whole
apparatus and screwed on to the connection from the boiler.
Fig. 13 represents a safety valve in which the valve D is held upon its seat C by
the action of a spring F compressed between the cover A' of the casing A and a
flange formed on the valve D, said valve being preferably hollowed out as shewn.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A safety valve for hot water boilers the parts of which are constructed,
arranged and combined substantially as herein before described under several
modifications with reference to the accompanying drawings.
2. In a safety valve for hot water boilers the provision of a cup, trap or like
device into which the valve or its seat dips to form a liquid seal substantially as
and for the purpose set forth.
Dated this 20th day of June 1895