Improvements in Means for Automatically Governing and Controlling the Pressure of Gas in Service Pipes and Mains.
Year: 1889

page_text: Date of Application, 11th Mar., 1889
Complete Specification Left, 11th Dec., 1889-Accepted, 11th Jan., 1850
PROVISIONAL SPECIFICATION.
Improvements in Means for Automatically Governing and Controlling
the Pressure of Gas in Service Pipes and Mains.
We ROBERT DEMPSTER and JOHN DEMPSTER of the firm of R. & J. Dempster
of the Gas Plant Works Newton Heath in the County of Lancaster Engineers do
hereby declare the nature of this Invention to be as follows:-
Our said Invention relates to gas governors and chiefly to such governors as are
used in connection with gas works and stations to regulate the pressure in the service
mains. The function of such governors as are at present in use is to maintain a
constant pressure in the mains, the fixed head of pressure being altered from time
to time in accordance with the consumption. by means of weights which are placed
upon or removed from the governor Hoat. The removal and addition of these
weights is effected by persons whose duty it is to see that the pressure in the service
mains is increased when the demand or consumption increases and decreased when
the demand or consumption decreases. This necessitates a great deal of attention and
considerable judgment. In our improved governor this proportionate increase and
decrease of weight upon the governor is effected automatically thus dispensing with
the aforesaid personal attention. We are aware that governors have been used which
are automatic in their action and control the pressure in the service mains in accor-
dance with the demand. In our improved governor, vessels containing liquids are
used as weights the liquid being transferred from one vessel to another through a flexible
or jointed tube accordingly as one vessel is above or beneath the level of the other.
In a simple form of our improved governor we place one vessel upon the crown of the
float and place the other upon the stationary side of the tank or vat containing the
liquid into which the float dips. The float actuates the spindle of the valve or valves
in the ordinary manner. The vessels are partly filled with mercury or with any other
suitable ponderous liquid or fluid and the communicating flexible or other tube is con-
nected to each vessel at or near the bottom or a syphon may be used to effect the
transfer from one to the other. When the float rises with its attached vessel the
liquid which is in the vessel on the float runs through the flexible or other tube into
the stationary vessel and the float is thus lightened. When the float sinks, as soon as
the vessel on the float falls beneath the level of the stationary vessel the said vessel
on the float receives the liquid from the stationary vessel and the float is weighted.
The downward movement of the float in the ordinary arrangement. of governors
usually effects the opening of the valve and as this downward movement is caused by
a demand for more gas from the service main this additional weighting of the valve on
its descent tends to open the valve more freely and expedites the fuller supply of gas.
On the other hand the rising of the float indicates that the supply is in excess of the
demand and the lightening of the float as it ascends helps to close the valve and
thus retard or cut off the supply. The level of the liquid in the weighting vessels
may be adjusted by the introduction into the vessels of displacing bodies which
adjust the liquid level so as to effect the requisite pressure upon or lightening of
the governor float throughout the entire range of its rise and fall, the liquid level
being raised in the case of an extended movement of the valve and lowered when
a less range is requisite. Instead of having one vessel on the float and one on
the stationary side of the governor, we might have two, three or more arranged
round the float or a liquid chamber running round the stationary top of the tank
and another similar chamber extending round the top of the float, the chambers
being connected at intervals by flexible or jointed or sliding tubes.
An important feature in our invention is that it can be readily applied to
existing governors in which the weighting and regulating of the valve is effected

page_text: manually. By a modification of our invention the weighting liquid vessels might
be placed at opposite ends of a lever pivotted at the centre of its length to a
bracket on
a stationary part of the governor such for example as the side of the
tank. The lever might be made hollow to act as a connecting pipe or a separate pipe,
either flexible or rigid might extend between the vessels. The float is in connection
with one of the weights and as it rises and falls a see-saw movement is com-
municated to the vessels the liquid being transferred through the connecting tube
from one to the other as their levels are altered. In this arrangement a smaller
quantity of mercury or weighting liquid will serve, as it is evident that the weight
transferred from one side of the pivot to the other has a double effect insomuch as
such transferrence not only relieves the float from direct weight but also adds to the
counterbalancing weight on the other side or vice versa. Either one such see-saw
weighting arrangement or more than one might be used in our improved governor.
In another modification the weighting vessel or vessels might be hinged to the side
of the tank and suspended by its outer end to a chain which passes over a pulley or
pullies and is connected to the centre or side of the float. This hinged vessel may
have a partition and as it rises and falls on its hinge the mercury or other fluid flows
from one side of the vessel to the other the arrangement producing a variable pull on
the suspending chain and so effecting the automatic adjustment obtained in the other
and foregoing examples.
Dated the 9th day of March 1889
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in Means for Automatically Governing and Controlling
the Pressure of Gas in Service Pipes and Mains.
We ROBERT DEMPSTER and JOHN DEMPSTER of the firm of R. & J. Dempster
of the Gas Plant Works, Newton Heath, in the County of Lancaster, Engineers,
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 and accompanying drawings:-
Our said Invention relates to gas governors and chiefly to such governors as are
used in connection with gas works and stations to regulate the pressure in the service
mains. The function of such governors as are at present in use is to maintain a
constant pressure in the mains, the fixed head of pressure being altered from time to
time in accordance with the consumption, by means of weights which are placed
upon or removed from the governor float. The removal and addition of these weights
is effected by persons whose duty it is to see that the pressure in the service mains is
increased when the demand or consumption increases and decreased when the demand
or consumption decreases. This necessitates a great deal of attention and considerable
judgment. In our improved governor this proportionate increase and decrease of
weight upon the governor is effected automatically thus dispensing with the aforesaid
personal attention. We are aware that governors have been used which are automatic
in their action and control the pressure in the service mains in accordance with the
demand. In our improved governor, vessels containing liquids are used as weights
the liquid being transferred from. one vessel to another through a flexible or jointed
tube accordingly as one vessel is above or beneath the level of the other.
To render our invention more clearly understood we will now proceed
more particularly to describe the same with reference to the annexed sheet of
drawings.
Fig. 1 is a sectional view of
a governing apparatus made in accordance
with our said invention a portion of the upper works being shown in side elevation so
as to render their working more clear.
Fig. 2 is an enlarged view in side elevation of the mercury vessels in the relative
positions of maximum lift and maximum fall.

page_text: Fig. 3 shows a modification of our invention.
In Fig. 1 the casing of the valve A by which the supply to the main is controlled
is marked B, the direction of the arrows showing the flow of gas. Cis the liquid
tank, D is the float; E are the mercury vessels mounted on the float; and F are the
mercury vessels mounted on the tank. The tank C contains the requisite quantity of
liquid and the float D which dips into it is also supported by chains a which pass over
wheels and carry counterbalance weights c. The float is also guided in its ascent
and descent by guide pullies d running on guides on the pillars e which carry the top
stay f. In the interior of the float D is a secondary central chamber D¹ of an internal
diameter corresponding to the maximum diameter of the valve A. This central
chamber D' is in communication with the feed side of the valve casing B by means of
the hollow cone g and extension / while the interior of the float D is in communication
with the delivery end of the valve casing B by means of the pipe . Thus the
chamber D and the valve A being subject to the same pressure balance each
other. The rise and fall of the float is caused by the variation of pressure on the
delivery side of the valve casing, that is to say by the variation of pressure in the
service main. The float is properly balanced in the first instance to the required
pressure by means of the weights k. When the pressure in the service main falls
beneath what is sufficient to meet the demand, the pressure in the float D, corre-
spondingly falls and the float descends so that the valve A which is suspended by
the rod from the float descends also and by virtue of its conical form causes an
increase of the opening m in the middle of the valve casing B and allows more gas
to flow into the service main and thus re-adjust the pressure therein. This increase
of pressure is also communicated to the float B and if the increase of pressure
should be excessive the float will rise again and diminish the through orifice m in the
valve casing. Our invention relates chiefly to improved means for assisting the
float B automatically by loading it with increased weight when it descends and thus
open the valve A to increase the pressure in the service main and by lightening it of
part of its load when it tends to ascend and thus close the valve A so as to reduce the
pressure in the main. To effect this object the general custom is to place additional
weights manually on the float when it is descending and to remove these weights in
the same manner when the float is rising. Of course like all methods which depend
upon individual judgment and attention this is an unsatisfactory and costly mode of
meeting the difficulty and attempts have been made with varying success to secure
the automatic application and removal of weight to and from the float. In our in-
proved method we use a vessel or vessels carried on the float and also a corresponding
vessel or number of vessels on the tank or other suitable fixed part, the vessels which
move with the float communicating with the fixed vessels by means of flexible or
sliding tubes, so that when mercury is placed in the vessels the vessels on the float
when lifted above the level of the fixed vessels discharge their contents into the said
fixed vessels and thus become "lightened or else when the vessels on the float fall
beneath the level of the fixed vessels the said moving vessels receive the mercury from
the fixed vessels and so become loaded. This action will be evident from a reference
to the drawings. For example in Fig. 1 E are the mercury or liquid vessels carried
on the float D. The fixed vessels F are shown in the drawing as attached to the top
of the tank C but they might be carried on any other suitable fixed part. A
flexible pipe connects the bottom of each movable vessel E to the bottom of its
corresponding fixed vessel F so that the mercury in the respective vessels is at liberty
to flow from one vessel to another according to their relative positions or levels. As
shown at Fig. 1 the vessels E and F may be said to occupy a medium position
relatively to each other. In Fig. 2 the vessel E is shown in full lines in its highest
position relatively to the fixed vessel F and consequently when in that position all of
the mercury has been transferred to the fixed vessel F. The dotted lines indicate the
vessel E in its lowest position relatively to the fixed vessel F in which case the whole
of the mercury will have been transferred to the moving vessel. To adjust the
proper normal pressure the fixed vessels F are carried on screwed standards
by turning which the vessels F can be set to any required height. To retard

page_text: or regulate the up or down movement of the float and consequently the opening
or closing of the valve A, we place conical displacing bodies s. t in the respective
mercury vessels E. F. The reason of the conical shape of these displacing bodies is
as follows. Suppose that the float D is in its lowest position by reason of low pressure
in the service main and the valve A consequently full open.
When the pressure in
the service main increases so as to raise the float D, the vessels E will rise until the
contained mercury begins to flow into the fixed vessels F. As the largest end of the
cone is at the bottom of the vessel F the area to be filled is not great and
consequently the level in the vessel F rises quickly while the level of mercury in the
vessel E falls correspondingly slowly owing to the smaller end of the cones occupying
the upper part of the vessel. The curves of the sides of the cones might be made
cognate to the curve of the exterior of the valve A. By the levels in the two
vessels thus keeping pace with each other at comparatively little proportionate
expense of weight to the vessels E and in sympathetic ratio to the curve of the valve
a too quick rise of the float is prevented and the valve A is closed sufficiently slowly
to permit the service pressure to attain the requsite height. On the descent of the
float a similar but converse operation takes place, for when the movable vessels E
descend to the level of the fixed vessels F the inflow of mercury entering the
restricted bottoms of the vessels E attain a level which is proportionately higher
than the loss of mercury from the fixed vessels, consequently the float is not too
suddenly weighted and the requisite pressure in the service main is established
without opening the valve A unduly fast. The shape or curve of the cones or
displacing bodies can be varied or they might be dispensed with altogether or
conical vessels might be used.
The remaining view Fig. 3 is a side elevation of a modified method of mounting
and disposing the said weighting mercury vessels as referred to in our provisional
Specification. In this arrangement smaller or fewer vessels may be used and also a
less quantity of mercury. In the example two vessels only are employed. The
vessels E F are suspended to a scale beam pivotted on a fixed standard v. The
vessels E F are connected by a flexible tube which allows the mercury from one
vessel to be discharged into the other when one vessel rises above the other. By this
arrangement we obtain a double effect for when the float D is being depressed for
example, not only is the weight in the float increased by the flow of the mercury
into the vessel E from the vessel T but also the counterbalancing effect of the vessel
is at the same time being lessened by the transference of the mercury. The proper
normal pressure in the service main can be adjusted by adding to or substracting from
the weights which are placed upon the suspension rod r. Instead of a flexible tube
a non-flexible connection might be used or the scale beam might be made hollow and
utilised as a conduit for the mercury or liquid.
The herein before described modes of weighting the floats of governors are subject
to further modifications. For example the weighting vessel or weighting vessels
might be hinged to the side of the tank and suspended at its or their outer ends
by a chain or chains passing over a pulley or pullies and connected to the centre
or side of the float. The said hinged vessel or vessels might have a partition or
partitions so that in rising and falling the mercury or liquid flows from one side to
the other the arrangement producing a variable pull on the suspending chain or
chains and so effecting the automatic adjustment obtained in the other and foregoing
examples. Our improved regulating apparatus is easily applied to existing gas
governors. To secure constancy of pressure on the supply side of the valve casing B
we might place a governor of ordinary construction in front of the supply opening in
the valve casing B.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
(1) The general arrangement, construction and combination of parts constituting a

page_text: liquid the said Governor being used either alone or in combination with an ordinary
governor for the purposes and substantially as described and as illustrated in
Figs. 1 and 2 of the drawings.
(2) In an automatic gas governor in which weighting vessels containing mercury
or liquid are used, placing a weighting vessel or weighting vessels on the top of
the float and connecting the same by means of flxible or non-flexible tubing or
conduits to a fixed vessel or fixed vessels carried on the tank of the governor or in
some suitable fixed adjacent part so that as the movable vessel or vessels rise above or
fall below the fixed vessel or vessels the weighting mercury or liquid is transferred
wholly or partly from one to the other in the manner for the purposes and substantially
as described and shown with reference to Figs. 1 and 2 of the drawings.
(3) The conical or other shaped displacing bodies in the weighting vessels or
conical weighting vessels for the purposes and substantially as described and shown.
(4) In an automatic gas governor arranging the mercury or liquid weighting vessels
upon a balanced scale beam and connecting the vessels by a flexible or non-flexible
tube so as to obtain a double effect of increase or decrease of the weight of either of
the vessels simultaneously with an increase or decrease of the opposite counter-
balancing weight at each end of the beam substantially as described and as illustrated
at Fig. 3 of the drawings.
Dated this 10th day of December 1889
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.