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Патент USA US2406243

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Aug. 20, 1946.‘ I
Filed June 21, 1943
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Patented Aug. 20, 1946
2,406,243 '
VALVE‘? ,; ‘5 '
Norman‘ B.*New'ton and Richard Fennema, Chi
‘ cago, Ill., assignors to Crane 00., Chicago, 111.,
a corporation of Illinois
Application June 21, 1943, Serial No. 491,714
'~ I _
‘3 Claims.
(C1- 251-.-27)
This invention relates to‘ valves. More particu
larly, it pertains to a novel form of seat and clo»
closure vibrations of plug type closure members
usedv for throttling non-compressible ?uids.
sure member combination in valves and is espe- ‘
cially suitable for throttling service.
To those
who are experienced or skilled'in'the art. it is
well recognized that the latter type of service
in which the valve is only partially open is one of
the most severe forms of working conditions to
which 'a valve may be subjected. The percentage
of valve failures has accordingly been very high 10
on this type of service.
In order to obtain a true and more complete ap
preciation of our invention and the nature of its
tion'to provide means for eliminating disc or valve
‘ It is a further important object of this inven
tion to dispel the low pressure zone caused by
the passing and subsequent collapsing of vapor
bubbles within the zone of higher pressure thus
causing the high frequency impact which creates
disc vibration. Speci?cally, such objectionable
low pressure zone is dispelled and cavitational
tendencies accordingly inhibited by feeding in a
fluid immediately adjacent thereto at a higher
static pressure.
accomplishments, there should exist, at the out
Other equally important objects and advan
set, an understanding of certain fundamental 15 tages will become apparent upon proceeding with
principles of, hydraulics pertaining especially to
the following speci?cation read in light of the
the ?ow of ?uid under high velocity through rel
accompanying , drawing, in which
atively restricted ori?ces.
Fig. 1 is a fragmentary sectional view of a pre
For example, it should be understood that an
ferred embodiment of our invention.
elastic column held rigidlyrat one extremity and 20 Fig. 2 is a fragmentary sectional view of a modi
struck at its free extremity will tend to vibrate
?ecl form of the invention.
at its natural frequency. Further, the static pres
Referring now to the drawing and particularly
sure of any ?uid decreases as the velocity in
to Fig. 1, the numeral I is used herein to desig
creases and with liquids, as this decreasing pres
nate a conventional form of bridge wall or dia
sure approaches the vapor pressure of the liquid, 5 25 phragm of a valve body or casing (not shown)
vapor bubbles will form, which phenomena is
having a horizontal portion, as indicated, in
termed cavitation. As these vapor bubbles pass on
which a body seat ring 2 is threadedly or other
into a lower velocity and into higher static pres
wise attached, the line pressure being on the
sure zone, they collapse and liquid rushes in to
lower or underside of the valve diaphragm I. The
?ll their voids. Therefore very appreciable and
substantial high frequency impacts are imparted
body seat ring 2, tightened in place by the wrench
engaging lugs I0, is preferably provided with a
tapered or frusto-conical seating portion 3 which
to'the con?ning walls of the conduit or container
which is an objectionable effect of cavitation.
may be either faced with a hard seating mate
More speci?cally, in the case of a throttle valve,
rial, as indicated, or else provided with the seat
one of the conduit walls is the valve closure mem-, 35 ing surface integrally as a part of the body seat
her or disc, and in this particular application the
ring. Preferably, although not necessarily, just
disc is preferably attached rigidly to thevalve
below the tapered seating portion 3, the seating
stem and the stem in turn supported only at
member is formed with a cylindrical passage des
its upper extremity in the stui?ng box packing.
ignated 4 within which the tapered or plug type
The resultant eifect of cavitation is the constant 40 ‘closure member 5 with its cylindrical shank 6
striking of the disc, which causes the stem and
is relatively snugly ?tted. ‘As shown in the closed
disc assembly to vibrate at its natural frequency.
' position of the valve, the tapered portion ‘I of the
It is therefore an important object of this in
closure member seats on the corresponding ta
vention to provide a novel means for minimizing
pered surface 3 of the body seat ring and when
cavitation by the introduction of liquid under rel 45 the valve is in its throttle position, it should
atively high static pressure to that restricted
be understood as being just slightly lifted or
zone where the high velocity and low static pres
removed from such seating contact as described.
sure would otherwise support the objectionable
A portion of a valve stem 8 is shown in the frag
cavitational tendencies.
mentary assembly, being threadedly rigidly at
It will be further apparent, in connection with 50 tached to the disc 5 as indicated at 9. The trans
the following description, that the high pressure
versely positioned pin [I and the weld seal [2
can be introduced either through the closure
serve to hold the threaded shank of the stem
member or through the valve seat with substan
?rmly in position against rotational and axial
tially the same bene?cial results.
It is a further important object of this inven
Thus far the description hereinabove given per
body seat ring may be dispensed with, if desired,
depending upon the nature of the line service
conditions encountered. Also the body seat ring
' tains‘ to a conventional type of globe or angle
valve. Now proceeding with the essential portion
of our inventive contribution, it has ‘been discov
ered that the throttling problems above referred
may be annularly chamfered at its lower or inlet
as indicated at 18.
to can be overcome by providing the lower por- 5 portion,
The'particular manner in which the introduc
tion of the closure member with a preferably cen
' tionoi high pressure ?ow takes place transverse
" trally positioned apertured passage, as indicated
ly‘ adjacent to the seat openingmay. vary' quite
at E3, and having a plurality of radially extend
substantially, and it is therefore the desire to be
ing passages ‘iii discharging therefromjhe num
limited only within the scope of the appended
ber of passages varying with the valve size and 10 claims interpreted in light of the prior art.
‘ service conditions. Thus the closure member is
We claim:
placed in the throttled position to form a rela
1.. In a plug type valve, a valve. closure member
tively restricted passage around the seat, thereby
of the .throttling type, a removable seat therefor,
eliminating the usual vibration which heretofore
' has been set up and has been foundso objection- l5
able in its‘ damage to the valve seat and closure.
combined annular and transverse passagescon
structed and arranged to permit communication
“with the inlet of the said valve for directing ?uid
member. By providing the transversely extend
from the inlet end of the‘ closure member through
ing passages ill, means have been established
passages to an annular passage between the
whereby the usual high Velocity ?ow of ?uid into
closure member and the said seatwhen the clo
thesaidannular opening and past the seatand 20 sure
member is in the'throttled. position,rsaid
closure member contacting surfaces is affected ' annular
passage being sealed'by the said closure
to an extent that cavitation is very substantially
minimized.’ It. Will be apparent that this is ac
' complished primarily by the introduction of ?uid ..
member when same is in closed position, the said
closure member having ‘a .irusto-cOhical throt
lip positioned within 1 the seat 7 opening
under a relatively high static pressure to'that ‘25 tling
whereby upon slight opening or throttling of the
restricted-zone substantially transverse and im
said closure ‘member the ?ow between the throt
mediately adjacent to the valve seat where the
tling lip and the inner annular walls of the said
high velocity and the low static pressure other
wise have supported cavitational tendencies inf, seat passes over the'j‘apertures of the transverse
prior valve structures.
1 An annular groove in the closure member has
30‘ passages.
2. In a valve, the combination includinga valve
closure member of ‘the plug type,'a tapered seat
transverse passage means having an
of cavitational tendencies in line ?ow by locating
[inlet end disposed to. receive line flow. from the
the same, as indicated at It», around the valve'disc ; ~
portion immediately adjacent to the section en-v 35 inlet end of the ‘closure member and communi
been found helpful in assisting inthe elimination
tering the cylindrical orstraight part A of the
body seat ring.’ H'oweven'relatively satisfactory
results under certain conditions have been accom
cating ‘with the valve seating contact surface be
tween the said closurememberand the said seat
whereby upon partial opening of the valve cavita
tion. may be minimized V therebetween by‘ the ' in
' groove in on the valve closure member and con; 40 troduction ofa diverted portion of the line fluid ‘
plished without ‘employment of the annular”.
versely it may‘ be applied to thefséat' ring with
V V acceptable results.._
under relatively high static pressure in'a direc
, tion substantially transverse tothe valve seating
_ contact surface, the said closure member having
atapered throttlinglip positioned within the seat '
Referring now to the modi?ed form‘, in Fig‘ 2,
in somercases because of structural conditions en-»::»‘ opening and over 'which?line fluid'?ows imme
countered it may be desirable'fto introduce the
,_ high pressure cavitation minimizing flow through
the valve seat-ring rather than through the clo
1» sure member and, as indicated, thismayv be easily
accomplished by simply vertically drilling an an-w;
diately upon placing the closure member in 'a
throttled position.
3; In a plug type throttling valve, the combi
nation withja valve seat and a plug typeiclosure
therefor, of passage means provided in
- nular portion of the body seat ring longitudinally 50
. at the'desired number of locations, as indicated
at It, and having in communication with each
the transversely extending ‘horizontal passages I‘!
. saidclosure member. for discharging line ?uid di
rectly- and radially into the-annular port opening
between the valve seat and the closure member,
which may be either drilled through, as indicated,» . said passage being disposed to discharge line ?uid
or else may be suitably plugged separately at the 55 immediately upon unseating movement of said
closure member, the throttling portion of the said
end adjacent the threads. Obviously, as shown,
member being of frusto-con'ical form ad
the seat ring threads by their-engagement with
jacent the seating contact portion of the said clo
the diaphragm wall I will serve conveniently as
sure member.
a plug at the outer end of the passage l1. Here
‘similarly in the instant modi?cation the annular ‘50
groove l5 either in the closure member 'or-in the
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