CA1321526C

CA1321526C - Throughflow regulating valve

Info

Publication number: CA1321526C
Application number: CA000583422A
Authority: CA
Inventors: AAGE MõLGAARD; Niels Peter Grand Graversen
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1987-12-09
Filing date: 1988-11-17
Publication date: 1993-08-24
Anticipated expiration: 2010-08-24
Also published as: DK596288D0; JPH01214910A; SE8804192D0; SE469729B; DE3741676A1; DK596288A; DK167038B1; DE3741676C2; SE8804192L

Abstract

Abstract A throughflow regulating valve has a second throttling point (13) in addition to the first throttling point (7) formed by the valve seat (6) and closure member (4). This second throttling point is formed with the aid of a recess (11) in the circumferential wall (10) of a rotary insert (8) cooperating with an aperture (12) in the valve housing (1). The closure member is actuated by a servo element (17) in a servo element housing (14) which is rotatably connected to the valve housing (1) but fixed to the rotary insert (8). In this way, the second throttling point (13) can be conveniently set.
The setting is recognisable from the outside.

Fig.1

Description

13215~

DANFOSS A/S, DK-6430 NORDBORG
Throughflow Regulatlng Valve The invention relates to a throughflow regulatine valve in whlch the throtting point formed by the valve seat and closure member 19 ln serles wlth an adJustable second throttllng polnt and the valve houslng 19 connected to a servo element houslng whlch ~3 subdlvided int~ two pre~sure chambers by a movable dlvldlng wall, such as a dlaphragm~
connected to the closure member by a valve rod, the pressure chambers belng connectable to respective passages leadlng to pressure mea3uring points in front Or and behind the second throttling point, one Or the passages extendlng through the valve rod to an lnternal pressure measurlng point.

Such a throughflow regulatlng valve is known from DE-OS 23lS045. The servo element 19 biassed by the pressure drop at the second throttle.
The valve therefore works as a quantity regulator which llmits the max-lmum flow to a value dependlng on the settlng of the second throttllng polnt. The second throttllng polnt ls formed wlth the aid of a helical sprlng whlch 19 dlsposed coaxlally to the valve seat on the side thereof remote from the closure member and 19 compressable by a set-screw. The latter changes the gap width between the helical convol-utlons and thus alters the throttle cross-sectlon. The servo element housing 19 flxed to the valve houslng. One of the pressure chambers Or thls servo element houslng 19 connected to the pressure measurlng polnt wlthln the hellcal sprlng by way of a passage extendlng through 13~ 52~
the valve rod. The other pre3sure chamber ls connected to the pressure measurlng polnt beyond the hellcal spring by way of a condult extendlng outslde the houslng. Rellef bellows extend between a dlvldlng wall Or the houslng and a ba3e of the bellows connected to the valve rod. The chambers to both sides of this bellows base are connected by way Or passages to the chambers on both sldes of the rlrst throttllng polnt.
Thls leads to rellevlng the pressure Or the clo~urc member and thus to compensatlon Or pressure rluctuatlons.

In ths known throughflow regulatlng valve, the second throttllng polnt and thus the deslred maximum flow can be changed only wlth the ald Or a tool for the setscrew. The extent of alteration cannot be detected from the outside. This is a partlcular disadvantage when such valves are bullt into heatlng lnstallatlons to serve as branch valves ln the parallel legs of plplng and are then to be 90 ad~usted that a pressure balance 19 obtalned ln the heating lnstallatlon, that 19 to say that the units to be supplied in all the legs are always supplied wlth a sufrlclent quantity of water durlng normal pressure conditions. In addition, it is a nuisance that a pressure signal conduit leads from the valve housing to the servo element housing.

DE-AS 126l722 discloses a radiator regulating valve in which, for the pUrpose Or presetting the flow, a second throttling point 19 provided whlch 18 formed by at least one receAs in the circumferential bore Or a rotary inssrt concentric with the valvs axls and an apertur~ ln the valve houslng cooperatlng wlth ths clrcumferential wall. This rotary ~ .

~' . ...

insert has a carrler at the top, that 19 engagable by a spanner, and a scale whlch cooperates with a marking on the valve housing.

The lnventlon is based on the problem oF pro~ing a throughflow valve Or the a~orementioned kind in whlch the ad~ustment Or the second throttllng polnt i8 effected more slmply and there 13 the posslbility Or seelng the resultlng ad~ustment from the outside.

This problem 19 so1ved accordlng to the inventlon in that the second throttllng polnt 19 formed by at least one recess ln the clrcumfer-entlal wall Or a rotary ln~ert concentrlc wlth the valve axls, the recess cooperatlng wlth an apert~re ln the valve houslng, and the servo element houslng 19 rotatably connected to the valve houslng but flxed to the rotary lnsert.

By uslng the rotary lnsert and connectlng lt to the servo element houslng, one obtalns a very readlly ad~ustable second throttllng polnt. Generally, no tool 13 requlred. Instead, lt 19 only necessary to grasp the servo element houslng and to turn lt for settlng purposes.
The rotary posltlon 19 at the same tlme a measurement Or the cross-sectlon of the openlng or the set amount Or flow.

There are the most varled posslbllltles for formlng the recesses. For example, the clrcumferentlal bore can contaln a plurallty of recesses Or dlfrerent cross-sectlons. However, the clrcumferentlal wall can also contaln only one recess Or whlch the helght varles ln the clrcum-- 132~26 ferential direction. In all cases, turnlng Or the servo element housing leads to a change in the effectlve cross-section of the second thro-ttling point that is made free by the housing aperture.

Advantageously, the valve rod contains anaxlal passage connected at one end to the pressure measuring point within the rotary insert and at its other end to the pressure chamber of the servo element housing that is remote from the closure member. Suoh an axlal passage can be accommodated without difflcultles ln the valve rod.

, In a particularly slmple embodiment, the valve rod i9 formed by a tube having at one end a screwthread for screwing in a hollow nipple passing through the dividing wall and at the other end a screwthread for screwing ln a screwthreaded splgot connected to the closure member, wall apertures being provided in its vicinity.

Further, lt 18 recommended that the pressure chamber of the servo element housing facing the closure member should extend up to the rotary lnsert and be connected by a first passage section between the rotary insert and the servo element housing as well as a seond passage section ln the valve housing to an lnternal pressure measuring point outside the rotary insert. In thls way, the second passage can also extend completely wlthin the housings. A very robust construction is obtained.

The first passage section can, for example, be formed by at least one groove at tbe outside of the rotary insert. Another possib1lity 19 ~,: ,., 215~6 that the servo element houslng and the rotary lnsert are lntercoupled by way of axlally extendlng teeth and grooves and the grooves have an enlargement extendlng beyond the cross-sectlon of the teeth. In both cases, very llttle addltlonal fabrlcatlon 19 requlred.

A partlcularly good indicatlon 19 obtalned lf a scale and a pointer are provided on the servo element housing and the valve housing.

Further, the servo element housing may comprlse proJectlons to serve as handgrlps for turnlng. Thls racilitates the ad~ustment. The proj-ectlons may al90 serve as polnters.

In a preferred embodlment, lt ls ensured that on the slde Or the valve seat remote from the rotary lnsert there 19 a bore lnto whlch there engages a compen3atlng plston connected to the closure member, and that a passage ln the valve houslng connects the chamber on the side Or the compensatlng pl3ton remote from the closure member to the chamber disposed outside the rotary in~ert. By slmple means and wlthout addltlonal passages ln the valve rod, one obtalns a compen-sating apparatus which compensates the influence Or pres3ure fluct-uations on the closure member.

It 19 also advantageous for the pr.essu~echamber Or the servo element houslng faclng the closure member to be selectlvely connectable to the lnternal pressure measurlng point outslde the rotary lnsert or, for the purposes Or connectlon to an external pressure measurlng polnt, to - 1321~2~
an external pre3sure connectlon. One and the same valve can therefore be selectlvely employed as a quantlty regulator or as a differentlal pres3ure valve. The latter can, for example, hold constant the pres3-ure diffe~cebetween a supply leg and a return leg Or a heating installation. A slngle type wlll therefore suffice as a branch regul-atlng valve whlch ls select~vely regulated dependlng on the amount. of throughflow or on the pressure dlfference.

In a preferred constructlon, a bore passlng through the wall Or the valve housing opens into a connecting chamber between rirst and second passage sectlons and in this bore one can selectlvely insert a closure plug or a connecting nipple which covers the mouth of the second passage section. ~y using the closure plug, one obtains a quantity regulatlng valve and by u~ing the connectlng nipple a differential pressure regulatlng valve.

The inventlon will now be descrlbed ln more detail wlth reference to preferred examples lllustrated ln the drawlng, whereln Flg. 1 is a longitudlnal section through a rlrst embodiment Or a thr-oughflow regulating valve according to the invention;

Flg. 2 is a modifled form of the rotary lnsert;
~' ' ~; , - 1321~2~
Flg.3 is a longitudinal section through a second embodlment of a throughflow regulatlng valve according to the invention which 19 connected as a differential pressure regulating valve; and Fig. 4 is a fragmentary longitudlnàl 3ectlon through a modifled valve connected aq a quantity regulating valve;

Fig. 5 is a sectlon along the llne A-A in Fig. 3; and Flg. 6 is a plan~ view of the Fig. 3 construction.

The quantity regulatlng valve of Fig. 1 comprise3 a valve housing 1 with a chamber 2 on the supply side and a chamber 3 on the discharge side. A closure member 4 connected to a valve rod 5 cooperates with a valve seat 6. This forms a first throttling point 7. Inserted in a bore concentrlc with the closure member, there i9 a rotary insert ô

which bounds an internal chamber 9 surrounding the closure member 4.
The circumferential wall 10 of this rotary insert 8 i~ provided with recesses~ 11, 11', 11" which, in con~unction wlth an aperture 12 in the valve housing 1, form a :9econd throttling point 13 in series with the first throttling point 7.

- 1321~26 A servo element housing 14 comprlses an upper portlon 15 and a lower portion 16 be~ween whlch there i9 clamped a dlàphragm 17 servlng as a dlvidlng wall. On the slde remote from the closure member 4, there 19 a flrst pressure chamber 18 connected by way Or a passage 19 ln the valve rod 5 to wall apertures 20 near the connectlon to the closure member 4, to form a rirst pressure measurlng polnt 21. The pressure chamber 22 on the slde facing the closure member 4 extend3 up to the rotary insert 8 and comprlses a blasslng sprlng 23 whlch loads the valve ln the openlne dlrectlon. The lower portlon 16 has a sleeve-shaped portlon 24 overlapplng the rotary lnsert 8 and 19 rixed thereto.
At the boundlng surface there 19 a passage ~ectlon 25 whlch leads to annular chamber 26 ln the valve houslng 1. From here, a second passage sectlon 27 leads to the chamber 3 on the dlscharge slde. At the mouth, a second pressure measurlng polnt 28 19 formed whlch ls con-nected by way of the passage sectlons 25 and 27 as well as the annular chamber 26 to the second pressure chamber 22.

The rotary unlt conslstlng of the servo element houslnK 14 and rotary lnsert 8 19 held ln place wlth the ald of a screwthreaded sleeve 29 and an abutment rlng 30, a seallng ring 31 belng provlded to seal agalnst the outside.

The flow through the second throttllng polnt 13 causes a pressure drop whlch 19 derlved from the pressure measurlng polnts 21 and 28 and acts on the dlaphragm l7. As soon as a predetermlned value as governed by the sprlng 23 has been exceeded, the closure member 4 moves ln the - 1321~2~
closing direotlon such that the set amount Or flow ls not exceeded.

By turnlng the rotary lnsert 8 wlth the ald Or the servo element houslng 14, a dlfferent cros~-sectlon can be set for the second throttllng polnt l3. Dlfrerent llmltlng values are then obtalned. As wlll be explalned hereinafter, , the set amount of flow can be read off from the rotary posltlon Or the servo element housing 14.

A closing piston 32 can be pushed into the lnterior of the servo element houslng 14 wlth the aid Or a screw 33. It therefore rorms a locking arrangement wlth which the closure member 4 can be brought to the closlng posltion, for example, when the associated leg ln a heatlng lnstallatlon 19 to be emptied.

Flg. 2 lllustrates an embodlment showlng a modlfled rotary insert 108 whlch dlffers from that ln Flg. l ln thatonly one recess 111 18 prov-lded ln lts clrcumferentlal wall 110, lts helght lncreasing ln the clrcumrerentlal dlrectlon. Here, agaln, a varlable passage 3ectlon can be achieved for the second throttllng polnt 13 ln cooperatlon wlth the houslng aperture 12.

In the embodlment of Flgs. 4 to 6, correspondlng parts are deslgnated by reference numerals lncreased by 20~. The servo element houslng 214 19 flxed to turn wlth the rotary inset 208 by way of gearlng. As ls shown ln Flg. 5, teeth 234 on the sleeve 224 Or the servo element houslng 214 engage ln complimcntary grooves 235 Or the rotary lnsert .

.

~ 132~ 5~6 208, all belng surrounded on the outside by a sleeve 236. The grooves 235 contain enlargements 225 which extend beyond the cross-section of the teeth and form the first passage sectlon. These depresslons 225 are also contlnued at the foot of the sleeve 224 and ring 236.

The valve rod 205 conslsts of a tube havlng at the upper end a screw-thread 237 for lnsertlng a nlpple 238. The nlpple passes through the diaphragm 217 and brlngs about communication wlth the upper pressure chamber 218. At the lower end of the plston rod 205 there ls a screw-thread 239 for screwlng ln a screwthreaded splgot 240 whlch ls con-nected to the closure member Z04.

The closure member 204 ls connected by way of an extension 241 to a compensatlng plston 242 whlch engages ln a bore 243 of the valve housing 201. The plston dlameter 19 equal to the diameter o~ the seat. The chamber 244 beneath the compensating piston is connected by way Or a houslng passage 245 to the chamber 203 on the discharge side contalnlng the pressure measurlng polnt 228. Consequently, one obtains automat~ic pressure compensatlon of the closure member 204.

.
The valvo housing 201 or the sleeve 229 is provided wlth an attachment 246 whlch, as is shown ln Flg. 6, has a scale graduated ln ~/h. The servo olement houslng 214 ls provided wlth an attachment 247 having pro~ections 248 as handgrlps for turnlng purposes. One radlal pro-Jectlon 249 sorves as a polnter for cooperatlng wlth the scale. The , ~ ~

two attachments 246 and 248 are concentrlcally gulded wlth respect to each other ln that axial ribs 250 of the attachment 240 engage ln an annular groove 251 of the attachment 247.

A -bore 252 in the valve houslng 201 ls provlded with a closure plug 253 as shown ln Fig. 4. Such a valve operates as a quantlty regulating valve, as does that Or Flg. l. However, lnstead of such a closu,re plug 243, one can also gcrew the connectlng nlpple 254 of Flg. 3 lnto the bore 252. In thls case, one obtalns an external connectlng point 255 through whlch one can make a connection to an external pressure measurlng point. The connectlng nipple 254 covers the mouth of the housing bore 227 90 that the internal pressure measuring point 228 19 made lneffectlve. In thls way, one obtains a pre~sure dlff-erence regulating valve wlth the ald Or whlch the flow through one leg can be made dependent on the pressure difference between the supply p~ssureand the return pressure. The force of the spring 223 normally oorresponds to a pressure of O;l b~r.This is the value usually desired between the supply and return of heating installations. If a different pressure dlfference is to be maintalned, the spring 223 may be ex~
changed~

Two nlpples 256 and 257 at the bottom Or the valve housing 201 can be employed for connecting measurlng apparatu~ or for emptying one leg.
. .

The 8prlng 223 re~ts on a supportlng rlng 258 whlch loads a ~eallng rlng 259 for seallng the valve rod 205. This supporting ring contalns depresslons slmllar to the depresslons 225.

' . . .

Claims

1. A throughflow regulating valve having a valve housing and in which a first throttling point formed by a valve seat and closure member is in series with an adjustable second throttling point and the valve housing is connected to a servo element housing which is sub-divided into pressure chambers by a movable dividing wall, such as a diaphragm, connected to the closure member by a valve rod, the pressure chambers being connectable to respective passages leading to pressure measuring points in front of and behind the second throttling point, one of the passages extending through the valve rod to an internal pressure measuring point, characterised in that the second throttling point is formed by at least one recess in a circumferential wall of a rotary insert concentric with the valve axis, the recess cooperating with an aperture in the valve housing, and the servo element housing being rotatably connected to the valve housing but fixed to the rotary insert.

2. A throughflow regulating valve according to claim 1, characterised in that said insert circumferential wall has a plurality of recesses of different cross-section.

3. A throughflow regulating valve according to claim 1, characterised in that said insert circumferential wall comprises a recess of which the height continuously increases in the circumferential direction.

4. A throughflow regulating valve according to any one of claims 1 to 3, characterised in that the valve rod comprises an axial passage which is connected at one end to said internal pressure measuring point within said rotary insert and at its other end to that pressure chamber of the servo element housing which is remote from the closure member.

5. A throughflow regulating valve according to claim 4, characterised in that said valve rod is formed by a tube which is provided at one end with a screwthread for receiving a hollow nipple passing through the dividing wall and at the other end with a screwthread for receiving a screwthreaded spigot which is connected to the closure member, and having wall apertures in its vicinity.

6. A throughflow regulating valve according to any one of claims 1 to 3, characterised in that the pressure chamber of the servo element housing facing the closure member extends up to the rotary insert and is connected by way of a first passage section between the rotary insert and servo element housing as well as a second passage section in the valve housing to an internal pressure measuring point outside the rotary insert.

7. A throughflow regulating valve according to claim 6, characterised in that the first passage section is formed by at least one groove at the outside of the rotary insert.

8. A throughflow regulating valve according to claim 6 characterised in that the servo element housing and rotary insert are intercoupled by way of axially extending teeth and grooves and the grooves contain an enlargement beyond the cross-section of the teeth.

9. A throughflow regulating valve according to claim 8 characterised in that a scale and a pointer are provided on the servo element housing and the valve housing.

10. A throughflow regulating valve according to claim 9, characterised in that the servo element housing comprises projections as handgrips for turning.

11. A throughflow regulating valve according to any one of claims 1 to 3, characterised in that the side of the valve seat remote from the rotary insert is provided with a bore in which there is engaged a compensating piston connected to the closure member and that a passage in the valve housing connects the chamber on the side of the compensating piston remote from the closure member to the chamber disposed outside the rotary insert.

12. A throughflow regulating valve according to any one of claims 1 to 3, characterised in that the pressure chamber of the servo element housing facing the closure member is selectively connectable to the internal pressure measuring point outside the rotary insert or, for the purpose of connecting to an external pressure measuring point, to an external pressure connection.

13. A throughflow regulating valve according to claim 12, characterised in that a bore passing through the wall of the valve housing opens into a connecting chamber between the first and second passage section and that a closure plug or a connecting spigot which covers the mouth of the second passage section are selectively insertable into the said bore.