Fluid Pressure Governor.
Year: 1894

page_text: Date of Application, 12th June, 1894-Accepted, 28th July, 1894
COMPLETE DIBUITICA
Fluid Pressure Governor.
I WILLIAM HOFFMAN, a Captain in the United States Army, Nv. 25 S Street,
Salt Lake, Utah, U.S. America do hereby declare the nature of this invention and
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to devices for maintaining in one part of a system of pipes,
or of apparatus, or of an engine and communicating pipes or engines, an approximately
constant fluid pressure less than that existing in another part of the same, as for
example less than that of the supply pipe, main or engine; and its object is to
provide a fluid pressure governor and safety valve of simple construction that will
act efficiently, safely and automatically to prevent an injurious rise of pressure upon
the delivery side of the governor and under all circumstances to maintain on said
delivery side any desired predetermined pressure; and the invention consists in the
construction hereinafter described and particularly pointed out.
In the accompanying drawings:
Figure 1 is a vertical longitudinal section;
Figures 2 and 3 are partial sections of modifications.
Numeral 1 denotes a tube or cylinder having screw threaded nipples 2, 3 and 4
which are adapted to be connected respectively with a conduit or vessel 2' arranged
to supply a fluid under pressure, with a distributing or other conduit or vessel 3' and
with an escape pipe 4'.
5 denotes a piston having as near an air tight connection with tube 1 as practicable
and adapted to move freely in said tube. It is provided with a rod 6 pivotally
connected to a weighted lever 7 having a fulcrum at 8, the weight 9 being adjustable
on said lever.
In Figure 3 I show a coiled spring 22 adapted to perform the office of the
weighted lever which latter device is preferred however because its action is more
certain and because it is not liable to be seriously injured by rust or weakened by
use. 23 denotes a stop to engage shoulders 13 and arrest the descent of the
piston.
The lever may be provided with a rotating fulcrum 21 as shown in Figure 2.
The tube 1 is provided with a removable screw plug 10 which is adapted to be
moved to adjust the tension of spring 22 if used. Said plug has an opening 11
angular in cross section for the free passage of the angular piston rod, and a
passage 111 for the escape of any water or other fluid that may leak past the piston.
This leakage escape as well as the safety vent 4 may communicate with any suitable
conduit or receptacle, as for example with a sewer.
The piston 5 has a passage 12 the lower end of which is bent at an angle to the
main part thereof and is adapted to register with the inlet passage of the nipple 2
when the piston is suitably situated. The shoulder or eud 13 of the piston is
adapted in its extreme lower position to bear on the plug 10. Its upper end will
bear against the interior shoulder 14 formed at the lower end of the outlet 3 when
the lower and bent end of its passage 12 registers with inlet 2. This shoulder 14
is made sloping or inclined as shown to freely expose at all times the upper end of
the piston to pressure in the pipes or apparatus on the low pressure side of the
governor.
15 denotes a strainer or filter to prevent the entrance of obstructions. This will
preferably be made of non-corrosive material as also will the entire governor and its
immediate connections.
The governor and the entire circulating system are adapted to be completely

page_text: drained by a three way waste cock 16. 17 denotes a drainage pipe. 18 indicates a
cock situated in pipe 20, said cock being normally closed but designed to be
opened for the purpose of washing the strainer or filter should it become clogged.
There being sufficient pressure in the supply system the opening of the cock 18
will cause a rush of fluid from the inlet pipe to branch pipe 20 past the strainer 15
which will carry away much if not all, of any obstructing matter that may have
gathered upon said strainer.
is
I regard my safety vent 4 and its working as an important feature of my
improvement. In the modifications illustrated said safety vent is situated so as to
communicate with a branch 12' of the passage 12, as in Figure 2, or directly with
the passage itself, as in Figure 3, when an undesired degree of pressure is
approached in the distributing pipes. The advantages of the safety vent will be
understood when it is considered that the device is intended, among various other
uses for which it is adapted, to be employed as the connecting link between a high
pressure water main or sub-main and a relatively low pressure distributing system
to which the existence of the high pressure would be injurious. In such a system
or construction it is desirable that an immediate relief or vent be afforded when
from leakage from the high to the low pressure side of the valve, or any other
cause, too high a pressure is approached in the distributing pipes. This is afforded
by the prompt action of such pressure to cut off the liquid supply by the automatic
lowering of the piston whereby communication with the main is closed. Normally
this cutting off action will be just sufficient to maintain a suitable supply in the
distributing system at the desired and predetermined pressure. But under
exceptional cases the piston will be promptly forced down, pressure from the main
entirely cut off and a relief or vent afforded through the safety outlet 4. But
ordinarily the increase above the normal of the back pressure, meaning thereby
the pressure on the delivery or low side of the governor, will not uncover the
outlet 4 but will expend itself in moving the piston a short distance, thereby
elevating the weight correspondingly and increasing the leverage of the weighted
arm so as to suitably open the inlet 2 after temporary excess of pressure
expended. This obviates the hammering so common in fluid circulating and
discharging apparatus. It will also in some measure guard against bursting pipes
or vessels by the expansion of liquids that precedes congelation or that may in
some apparatus be caused by heat or by fermentation. And also in a liquid
circulating apparatus, such as a domestic hot and cold water distributing system
including stand boilers and range water backs, considerable variation of pressure
may in some cases be caused by unusually hot fires with little or no drafts from
the bot water pipes and particularly if such a system communicates with hot water
circulating pipes and radiators which can be thrown into and out of circuit at will.
Variations of pressure in the distributing pipes tend to throw any automatically
acting valve situated therein and if such valve has too short a range of movement
it will be forced to and from its seat, upon slight variations with unnecessary
frequency, and in a manner to pound and make an objectionable noise. For this
reason I prefer to provide for some movement of my piston valve between the
closing of the valve and the opening of the safety outlet whereby small increments
of pressure may expend themselves upon the counterbalance, whether weighted
lever or equivalent, and without opening the safety outlet to waste the fluid. If
however the increase of pressure fully reaches the predetermined limit of safety
the piston will be moved sufficiently to open the safety outlet even though the
inlet be closed before the opening occure. The precise situation of the safety
outlet is not essential, provided only that it is arranged to communicate, at the
proper time, by movement of the piston, with the distributing system. That is the
situation of the outlet 4 may be varied it being only necessary that it communicate
freely with the passage 12 when the piston 5 is at its lowest position.
By my improvement the use of packing may be avoided when desired and also
the evils usually resulting from leakage since in no case can the pressure in the
distributing system be thereby increased beyond the desired limit. Further I

page_text: provide a strainer and means of cleansing it and also a three-way cock for
conveniently emptying the governor and the distributing pipes.
It is characteristic of my improvement that it provides, when desired or
necessary, a free and unobstructed communication between the low pressure or
circulating pipes and a safety vent. I thereby make full provision against leakage
and am thus able to dispense with leather or rubber packings such as ordinarily
required, particularly in the case of apparatus circulating corrosive fluids when the
entire apparatus will need to be made of glass or other like suitable material; and
I provide a distinct drainage such as 11 for leakage at the lower end of the valve
piston. It may be noted that when the inlet 2 is closed the pressure from the main
has no tendency to move said valve and that when it is open the only portion of
the valve surface adapted to receive said pressure in manner to move it in the
upward direction is that on the upper side of the short limb of passage 12 adjacent
to the inlet, a much larger surface consisting of that on the opposite side of said
limb and that on the top of the piston being subject to said pressure in manner to
move the piston down and close the valve which action is measurably counter-
balanced by the weighted lever as above stated.
It should be observed also that the governor can be choked and rendered
inoperative by sediment, such as lime, or by corrosion only when the inlet is shut
and the outlet open for the reason that at such time the weighted lever or its
equivalent is the only power tending to move the valve which power is always
limited and below the fluid pressure in the governor when the inlet is open.
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 1
claim is :
1. In a fluid pressure governor the tube 1 provided with suitable nipples 2 and 3
and a safety outlet 4; and the piston 5 having the bent passage 12, and the
weighted lever pivoted to the piston rod to counterbalance a part of the downward
pressure in the valve, the power arm of the said lever being lowest when the valve
inlet is open and horizontal when the safety outlet is open whereby the leverage
increases as the valve closes and reaches a maximum when the valve is closed,
substantially as set forth.
2. In a fluid pressure governor the tube 1 provided with suitable nipples 2 and 3
and a safety outlet 4; and the piston 5 having the bent passage 12, and means for
counterbalancing part of the downward pressure on the valve, said means exerting
a minimum effect when the inlet is fully open and a maximum when the safety
outlet is open and the inlet closed, and said valve having greater surface exposed
to the downward than to the upward pressure of the fluid, substantially as set
forth.
3. In a fluid pressure governor the tube 1 provided with suitable nipples 2 and 3
and a safety outlet 4; and the piston 5 having a bent passage 12, whereby the
passages through the nipples may communicate, said piston exposing more surface
to downward than to upward pressure, and when the inlet is closed exposing no
surface to pressure from the main in either direction of the piston's path; and
having means distinct from said upward pressure for moving it to open the inlet,
said means having a maximum effect when the inlet is closed, all substantially as
set forth.
4. The combination of a fluid pressure governor and a distributing system with
an inlet pipe 2 having a branch 20 and a strainer 15 the branch pipe being
provided with a cock whereby the fluid may either be cut off in said branch pipe
or be permitted to flow therethrough to wash the strainer, substantially as set
forth.
5. The combination of the cylinder having inlets and exits as described, the
piston having a passage therethrough and the counterbalance adapted to auto-
matically open a safety vent, substantially as set forth whereby the necessity of
packing is avoided, and whereby the device is made operative notwithstanding

page_text: accidental leakage, and whereby no choking by sediment or corrosion can occur
except when the inlet is shut and the safety escape open.
6. The combination of the cylinder having inlets and exits as described, the
piston having a passage therethrough and the counterbalance adapted to auto-
matically open a safety vent and a waste cock 16 whereby the circulating system
and the governor can be entirely drained, the necessity of packing avoided, and
the device made operative notwithstanding accidental leakage, and whereby no
choking by sediment or corrosion can occur except when the inlet is shut and the
safety escape open, substantially as set forth.
Dated this 12th day of June 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.