DK163374B

DK163374B - SAFETY VALVE FOR A WATER HEATER WITH A PRESSURE TANK

Info

Publication number: DK163374B
Application number: DK216588A
Authority: DK
Inventors: Thor Froelich Braathen
Original assignee: Braathen Thor F
Priority date: 1987-04-23
Filing date: 1988-04-21
Publication date: 1992-02-24
Also published as: FI881766A0; DK216588D0; GB2203820A; NO161281B; GB8808088D0; SE467016B; DK216588A; SE8801469L; NO161281C; DE3809465A1; SE8801469D0; FI86467B; NO871689D0; NO871689L; FI86467C; FI881766A; DK163374C

Description

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Opfindelsen angår en sikkerhedsventil til en med en tryktank indrettet vandvarmer, og som er indrettet til at kunne åbne for overtryk i tryktanken og er af den art, som er angivet i krav 1's indledning.The invention relates to a safety valve for a water heater arranged with a pressure tank, which is adapted to open for pressure in the pressure tank and is of the kind specified in the preamble of claim 1.

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Opfindelsen angår også en væskeslagsdæmper til montering mellem en overløbsslange eller et overløbsrør og udløbet i en sikkerhedsventil.The invention also relates to a liquid shock absorber for mounting between an overflow hose or overflow pipe and the outlet of a safety valve.

10 Den indledningsvis nævnte sikkerhedsventil skal kunne åbne, hvis vandvarmeren med videre udsættes for et overtryk som følge af, at tilgangsvandtrykket til tryktanken forøges, eller at trykket i tryktanken forøges på grund af vandets udvidelse ved opvarmning fra en lavere til en 15 højere temperatur.10 The safety valve mentioned above should be able to open if the water heater is further exposed to an overpressure as a result of the supply water pressure to the pressure tank being increased or the pressure in the pressure tank increasing due to the expansion of the water by heating from a lower to a higher temperature.

Der stilles forskellige krav til sikkerhedsventiler, og disse krav kan variere fra land til land, som f. eks.; 20 1. Åbningstryk 9 atø.Various requirements for safety valves are made and these requirements may vary from country to country, such as; 20 1. Opening pressure 9 ato.

2. Lukketryk - 10% lavere end åbnings trykket, dvs. 8,1 atø.2. Closing pressure - 10% lower than the opening pressure, ie. 8.1 ato.

3. Den udstrømmende vandmængde skal ved et tryk, som er 10% højere end åbningstrykket, dvs. 9,9 atø, være 6,5 25 liter pr. minut pr. kW max effekt til opvarmning af vandvarmeren. Ved 3 kW max effekt må sikkerhedsventilen således være i stand til at få en vandmængde på 19,5 liter pr. minut til at strømme ud ved et tilgangstryk på sikkerhedsventilen på 9,9 atø.3. The flow of water must at a pressure 10% higher than the opening pressure, ie. 9.9 oz, be 6.5 25 liters per liter. per minute kW max power for heating the water heater. Thus, at 3 kW max power, the safety valve must be able to obtain a water volume of 19.5 liters per unit. per minute to flow out at an inlet pressure of the 9.9 ato safety valve.

30 4. Det maksimale tryk i tilgangs-koldtvandsledningen til sikkerhedsventilen er 6 atø. Ved højere tryk skal der monteres en reduktionsventil.30 4. The maximum pressure in the inlet cold water line for the safety valve is 6 ato. At a higher pressure, a reduction valve must be fitted.

5. På sikkerhedsventilens udløb skal der monteres en overløbsslange eller et overløbsrør, som tjener til at 35 føre overløbsvandet til afløb, og som skal have en mindste indvendig diameter på 12,5 mm.5. At the outlet of the safety valve, an overflow hose or overflow pipe shall be used which serves to direct the overflow water to the drain and which shall have a minimum internal diameter of 12.5 mm.

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De for tiden benyttede sikkerhedsventiler åbner ved 9 atø og lukker ved 10% reduktion af dette tryk. .Det er meget vanskeligt at opnå en udstrømmende vandmængde på 19,5 liter pr. minut ved 9,9 atø og samtidigt opnå, at sikker-5 hedsventilen "lukker ved et lukketryk på 8,1 atø.The currently used safety valves open at 9 o'clock and close at 10% reduction of this pressure. It is very difficult to obtain an outflow of water of 19.5 liters per liter. At the same time, the safety valve "closes at a closing pressure of 8.1 ato.

For mange vandværker er det vanskeligt at holde vandtrykket nede på normaltrykket 6 atø i de perioder, hvor vandforbruget er lille. F. eks. kan vand trykket om natten 10 øges med mere end 50%.For many waterworks, it is difficult to keep the water pressure below normal 6 ato during periods when water consumption is low. For example, water pressure at night 10 can be increased by more than 50%.

Når udløbet fra en sikkerhedsventil tilsluttes en overløbsslange, som fører til et afløb, ændres sikkerhedsventilens karakteristik fuldstændigt, og tilslutningen med-15 fører følgende: Når tilgangsvandtrykket i ventilhuset overstiger 9 atø, åbner ventilen og fylder overløbsslangen med vand. Den sædvanligvis trykløse udløbsside/overløbsside får nu et 20 til tilgangstrykket tilnærmelsesvis svarende tryk, hvorved ventilen lukker, men straks efter åbner igen, idet tilgangstrykket atter øges. Ventilen åbner og lukker med hastigheder på 50-150 slag pr. minut. Disse trykstød er så hårde, at sikkerhedsventilen og vandtankens og rørenes 25 svejsninger kan blive ødelagt. Formålet med opfindelsen er at anvise en sikkerhedsventil af den indledningsvise nævnte art, som opfylder ovennævnte krav, og hvormed ovennævnte vanskeligheder er elimineret.When the outlet of a safety valve is connected to an overflow hose leading to a drain, the characteristics of the safety valve change completely and the connection results in the following: When the inlet water pressure in the valve housing exceeds 9 ato, the valve opens and fills the overflow hose with water. The usually pressureless outlet side / overflow side now receives a pressure approximately equal to the inlet pressure, whereby the valve closes, but immediately opens again as the inlet pressure is increased again. The valve opens and closes at speeds of 50-150 beats per minute. minute. These pressure shocks are so severe that the safety valve and the welds of the water tank and pipes can be destroyed. The object of the invention is to provide a safety valve of the type mentioned in the preamble which meets the above-mentioned requirements and by which the above-mentioned difficulties are eliminated.

30 Dette opnås ifølge opfindelsen ved hjælp af de trask, som er angivet i den kendetegnende del af krav 1 og de efterfølgende underkrav.This is achieved according to the invention by means of the trays set forth in the characterizing part of claim 1 and the subsequent subclaims.

Opfindelsen forklares nærmere nedenfor, idet der beskri-35 ves en på tegningen vist udførelsesform for en sikkerhedsventil, samt en med denne forbundet væskeslagsdæmper.The invention is further explained below, by describing an embodiment of a safety valve shown in the drawing, as well as a liquid shock absorber associated with it.

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Tegningen viser, fig. 1 en sikkerhedsventil ifølge opfindelsen set i snit, 5 fig. 2 den i fig. 1 viste sikkerhedsventil med tilsluttet overløbsslange og en imellem disse indskudt væskeslagsdæmper, og fig. 3 samme, men i større målestok og med væskeslagsdæm-10 peren set i snit.FIG. 1 is a sectional view of a safety valve according to the invention; FIG. 2 is the one shown in FIG. 1, a safety valve with an overflow hose connected and a liquid shock absorber between the two, and FIG. 3, but on a larger scale and with the liquid shock absorber cut in section.

Sikkerhedsventilen A består af et ventilhus 1 med et indløb 2 til trykvand og et udløb 7 til eventuelt overløbsvand, samt en mellem disse anbragt membranventil. Denne 15 består af et ringformet sæde 4 i et gennemløb 21, som forbinder indløbet 2 med udløbet 7, en membran 5 af gummi eller et lignende materiale, som er indspændt med sit perifere parti mellem et ringformet bryst i en i ventilhuset 1 indrettet ventilindføringsåbning 22 og en endeflade 20 6a på et i denne åbning 22 indskruet fjederhus 6. I dette fjederhus 6 er der anbragt en fjederforspændt spindel 8 med et spindelhoved 8a liggende således fjedrene i anlæg mod oversiden af membranen 5's midterparti 5a, at dettes underside trykkes fjedrende i anlæg mod sædet 4. Omkring 25 dette sæde 4 er der desuden indrettet et af huset 1 og membranen 5' s underside afgrænset ringformet kammer 20 med en mod udløbet 7 vendende åbning 20a, hvorigennem overløbsvand 3a kan strømme ud, når membranen 5 af et overtryk i tryktanken og dermed i indløbet 2 og gennemlø-30 bet 21 løftes fra sædet 4. Samtidigt opbygges der i ringkammeret 20 et vandtryk, som uden for sædet 4 påvirker undersiden af membranen 5 på en sådan måde, at denne løftes yderligere op fra sædet 4 og ventilens ringformede ventilspalterum herved forøges således, at udstrømningen 35 af overløbsvand 3a forøges tilsvarende. Spindelen 8, som strækker sig gennem en føringsåbning 10a i fjederhusets 6 bund 10, er desuden omgivet af en trykfjeder 9, som lig-The safety valve A consists of a valve housing 1 with an inlet 2 for pressurized water and an outlet 7 for any overflow water, as well as a diaphragm valve located between them. This 15 consists of an annular seat 4 in a passage 21 connecting the inlet 2 to the outlet 7, a membrane 5 of rubber or a similar material, which is clamped with its peripheral portion between an annular breast in a valve insertion opening 22 arranged in the valve housing 1 and an end face 20 6a on a spring housing 6 screwed into this opening 22. In this spring housing 6 a spring biased spindle 8 with a spindle head 8a is arranged so that the springs abut against the upper part of the diaphragm 5a of the diaphragm, so that its underside is spring-pressed into abutment. To the seat 4. Around 25 this seat 4 is also arranged an annular chamber 20 defined by the housing 1 and the underside of the membrane 5 with an opening 20a facing the outlet 7, through which overflow water 3a can flow out when the membrane 5 of an overpressure the pressure tank and thus in the inlet 2 and the throughflow 21 are lifted from the seat 4. At the same time, a water pressure is built up in the annulus 20, which outside the seat 4 affects u the bottom of the diaphragm 5 in such a way that it is raised further from the seat 4 and the annular valve gap space of the valve is thereby increased so that the outflow 35 of overflow water 3a is increased accordingly. The spindle 8, which extends through a guide opening 10a in the bottom 10 of the spring housing 6, is additionally surrounded by a compression spring 9 which

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i ger indspændt mellem bunden 10 og det forbi sædet 4 radialt ragende spindelhoved 8a. Spindelen 8's hoved 8a og membranen 5's midterparti 5a er samlet med indbyrdes samvirkende forbindelsesorganer i form af en fortrinsvis gevindskåret midterudboring 8b i spindelens 8 hoved 8a og en på membranen 5's overside udformet midtertap 5b til at skrue ind i udboringen 8b. Et fjedrende, sammentrykkeligt buf fer legeme 16, som har en større fjederkraft end trykfjederen 9, er anbragt mellem en ansats 17 i fjederhuset 6 og spindelhovedet 8 med et i forhold til dette eller ansatsen 17 aksialt indrettet forudbestemt spillerum 19, som svarer til membranen 5's maksimale løftehøjde under tryk. Dette bufferlegeme 16 ligger med sin ydervæg og ene ende an mod fjederhuset 6 henholdsvis indervæg og ansats 17, og har i forhold til membranen 5 ved sin anden ende et spillerum 18, som tilnærmelsesvis svarer til spillerummet 19 mellem bufferlegemet 16 og spindelhovedet 8a. Bufferlegemet 16's midteråbning 16a konvergerer i retning mod spindelhovedet 8a og ligger med sit smalleste afsnit centreret an mod trykfjederen 9's nedre ende, som igen ligger centreret an mod spindelen 8. Dennes øvre ende 8c strækker sig frit gennem en åbning 14a i et håndhjul 14, som ligger drejeligt an mod fjederhuset 6 med en cirkulær ansats 12, som samvirker med en ansats 6c på fjederhuset 6. Disse ansatse 12 og 6c omfatter samvirkende skrå flader eller eventuelt skrå flader og knaster til via en stopskive 15 ved spindelens ende 18c ved drejning og heraf følgende aksial bevægelse af håndhjulet 14 at løfte spindelen 8 og derved membranen 5 fra sædet 4 til regulering af gennemstrømningen og til eventuel tømning af tryktanken for vand.in gears interposed between the bottom 10 and the spindle head 8a radially projecting spindle head 8a. The head 8a of the spindle 8a and the central portion 5a of the membrane 5a are joined by interconnecting members in the form of a preferably threaded center bore 8b in the head 8a of the spindle 8 and a central pin 5b formed on the upper side of the diaphragm 5 to screw into the bore 8b. A resilient, compressible buffer body 16 having a greater spring force than the compression spring 9 is disposed between an abutment 17 in the spring housing 6 and the spindle head 8 having a predetermined clearance space 19 corresponding thereto or the abutment 17 corresponding to the diaphragm 5. maximum lift height under pressure. This buffer body 16, with its outer wall and one end, abuts the spring housing 6 and inner wall and shoulder 17, respectively, and has, relative to the membrane 5 at its other end, a clearance 18 which corresponds approximately to the clearance 19 between the buffer body 16 and the spindle head 8a. The central aperture 16a of the buffer body 16a converges in the direction towards the spindle head 8a and lies with its narrowest section centered on the lower end of the compression spring 9, which in turn is centered on the spindle 8. Its upper end 8c extends freely through an opening 14a in a handwheel 14 which pivotally engages the spring housing 6 with a circular shoulder 12 which cooperates with a shoulder 6c on the spring housing 6. These bosses 12 and 6c comprise cooperatively inclined surfaces or possibly inclined surfaces and engage via a stop disk 15 at the end of the spindle 18c by rotation and thereof. following axial movement of the handwheel 14 to lift the spindle 8 and thereby the membrane 5 from the seat 4 for regulating the flow and for possibly emptying the pressure tank for water.

Som det fremgår af ovenstående, er spindelen 8 indrettet således, at den kan bevæges yderligere aksialt mod bufferlegemet 16's fjederkraft ved hjælp af de nævnte uden for fjederhuset indrettede midler 12, 14 til tømning af tryktanken.As can be seen from the above, the spindle 8 is arranged so that it can be moved further axially against the spring force of the buffer body 16 by means of said means 12, 14 arranged outside the spring housing for emptying the pressure tank.

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Den på spindelen 8 virkende trykfjeder 9 har en på forhånd fastlagt længde og et på forhånd fastlagt fjedertryk med så flad en fjederkarakteristik som muligt, og trykfjederen 9 er desuden indspændt med en på forhånd fast-5 lagt afstand mellem fjederhuset 6's bund 10 og spindelhovedet 8a. Fjederhusets 6 indskruning i ventilindføringsåbningen 22 er begrænset af samvirkende stop 6b, 11, som er indrettet på henholdsvis fjederhuset 6 og ventilindføringsåbningen 22's yderende 11, og som tjener til dels at 10 opnå den tilsigtede indspændingskraft af membranen 5's perifere parti, dels den tilsigtede anlægskraft mellem membranen 5's underside og sædet 4.The compression spring 9 acting on the spindle 8 has a predetermined length and a predetermined spring pressure with as flat a spring characteristic as possible, and the compression spring 9 is also clamped at a predetermined distance between the bottom 10 of the spring housing 6 and the spindle head 8a. . The enclosure of the spring housing 6 in the valve insertion opening 22 is limited by cooperating stops 6b, 11, which are respectively arranged on the spring housing 6 and the outer 11 of the valve insertion opening 22, which serve partly to achieve the intended clamping force of the peripheral portion of the diaphragm 5 and partly the intended abutment force. the underside of the membrane 5 and the seat 4.

Når sikkerhedsventilen er monteret på en tryk tank og er 15 taget i brug, vil trykvandet 3 i indløbet 2 og gennemløbet 21, påvirke membranen 5's midterparti 5a inden for sædet 4. Når vandtrykket af en eller anden grund stiger til det indledningsvise omtalte åbningstryk 9 atø, løftes membranen 5 fra sædet 4 mod fjedertrykket fra trykfjede-20 ren 9, som har et fjedertryk, som er tilpasset det nævnte åbningstryk for vandet. Vandet strømmer da videre ud i ringkammeret 20 og herfra videre ud gennem dettes udløbsåbning 20a mod sikkerhedsventilens udløb 7, idet der i ringkammeret 20 herunder samtidigt opbygges et tryk, 25 som virker på den del af membranen 5's underside, som ligger uden for sædet 4, hvorved membranen 5 løftes yderligere med henblik på at slippe en større vandmængde ud, såfremt vandtrykket stiger over åbningstrykket 9 atø og op til et overtryk på 10%, nemlig 9,9 atø. Under denne 30 yderligere sammentrykning af trykfjederen 9 vil denne give efter eller kollapse. For at sikre, at membranen 5 ikke løftes så meget, at en ukontrolleret vandmængde løber ud gennem udløbet 7, er gummibufferen 16 indrettet med en hensigtsmæssig afstand 19 over spindelhovedet 8a, og som 35 følge af, at den har en større fjederkraft end trykfjederen 9, vil den hindre, at membranen 5 trykkes yderligere op.When the safety valve is mounted on a pressure tank and is in use, the pressurized water 3 in the inlet 2 and the passage 21 will affect the central portion 5a of the membrane 5a within the seat 4. For some reason the water pressure rises to the opening pressure 9 mentioned above. , the diaphragm 5 is raised from the seat 4 against the spring pressure from the compression spring 20, which has a spring pressure adapted to the said opening pressure for the water. The water then flows out further into the annulus 20 and thence further out through its outlet opening 20a towards the outlet 7 of the safety valve, while in the annulus 20, there is simultaneously built up a pressure 25 acting on the part of the underside of the diaphragm 5 which lies outside the seat 4. whereby the diaphragm 5 is further lifted to release a larger amount of water if the water pressure rises above the opening pressure 9 ato and up to an overpressure of 10%, namely 9.9 ato. During this further compression of the compression spring 9, this will yield or collapse. In order to ensure that the diaphragm 5 is not lifted so much that an uncontrolled amount of water flows out through the outlet 7, the rubber buffer 16 is arranged with an appropriate distance 19 over the spindle head 8a, and as a result of having a greater spring force than the compression spring 9 , it will prevent the membrane 5 from being pushed further up.

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Ved synkende vandtryk vil trykfjederen 9 via spindelhovedet 8a søge at trykke membranen 5 nedefter til anlæg mod sædet 4, og membranen 5 vil slutteligt blive bragt til anlæg mod dette sæde 4, når trykket er sunket til det 5 indledningsvis nævnte lukketryk 8,1 atø.With decreasing water pressure, the compression spring 9 will, via the spindle head 8a, try to push the diaphragm 5 downwards to abut the seat 4, and the diaphragm 5 will finally be brought into abutment against this seat 4 when the pressure is lowered to the closing pressure 8.1 at the beginning.

Fjederhuset 6 har en konstant afstand fra bunden 10 til sædet 4, når fjederhuset er skruet ind i ventilindføringsåbningen 22 med sin stopansats 6b liggende an mod 10 ventilindføringsåbningen 22's ydre ende 11. Som følge af, at trykfjederen 9 er fremstillet med det tilsigtede fjedertryk, samt at de øvrige dele har små tolerancer, vil membranen 5’s tilsigtede anlægstryk mod sædet 4 blive opnået ved montering af komponenterne. Der er således ikke 15 behov for nogen justeringsskrue til at opnå det rigtige fjedertryk.The spring housing 6 is at a constant distance from the bottom 10 to the seat 4 when the spring housing is screwed into the valve inlet opening 22 with its stop assembly 6b abutting the outer end 11. of the valve inlet 22 as a result of the pressure spring 9 being produced with the intended spring pressure, and that the other parts have small tolerances, the intended abutment pressure of the membrane 5 against the seat 4 will be obtained by mounting the components. Thus, no adjustment screw is needed to obtain the correct spring pressure.

Volumenet af ringkammeret 20, som også kan benævnes overløbsrummet, kan varieres ved at øge dets dybde, og under 20 fremstillingen eventuelt også ved samtidigt at variere udløbsåbningen 20a.The volume of the annulus 20, which may also be referred to as the overflow space, can be varied by increasing its depth, and during manufacture, possibly also by simultaneously varying the outlet opening 20a.

Ved hjælp af sikkerhedsventilen A's ovenfor beskrevne komponenter og disses virkemåde opnås følgende: 25The components of the safety valve A described above and their operation are obtained as follows:

Membranen 5 tætner for både tryksiden og overløbssiden, og den vil altid åbne, når trykket øges, selvom der forekommer forureninger og kalkbelægninger, fordi den ikke omfatter noget skørt eller metal mod metalsædet, hvor-30 imellem kalkbelægningen kan sætte sig fast.The diaphragm 5 seals for both the printing side and the overflow side, and it will always open as the pressure increases, even if contaminants and lime deposits occur because it does not include any brittle or metal against the metal seat, between which the lime coating can get stuck.

Trykfjederen 9 er konstrueret således, at den har et bestemt fjedertryk, og at dette øges så lidt som muligt ved yderligere sammenpresning, dvs. en fjederkarakteristik, 35 som er så flad som muligt.The compression spring 9 is designed so that it has a certain spring pressure and that this is increased as little as possible by further compression, ie. a spring characteristic which is as flat as possible.

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Fjedertrykket er tilpasset ud fra, at sikkerhedsventilen skal holdes tæt lukket op til et tryk på f.. eks. 9 atø, og at der i gennemløbet 21 i sædet 4 findes en bestemt diameter. Når sædet 4’s indre diameter er f. eks. 10 mm, 5 giver dette én trykoverflade på membranen 5's midterparti 5a, som er lig 2 *r2, eller 5 x 5 x 3,14 = 78,5 mm2. Fjederens styrke beregnes efter denne overflade og et vandtryk på 9 atø, som er åbningstrykket.The spring pressure is adapted from the fact that the safety valve must be kept tightly closed up to a pressure of, for example, 9 atoms and that a certain diameter is found in the passage 21 in the seat 4. For example, when the inner diameter of the seat 4 is 10 mm, 5 this gives one pressure surface on the middle portion 5a of the membrane 5, which is equal to 2 * r2, or 5 x 5 x 3.14 = 78.5 mm2. The strength of the spring is calculated according to this surface and a water pressure of 9 ato, which is the opening pressure.

10 Når vandtrykket stiger op over åbningstrykket på 9 atø, til f. eks. 9,8 atø, dvs. 10% overtryk, vil membranen 5 som nævnt på grund af trykopbygningen i ringkammeret 20, blive løftet yderligere fra sædet 4, hvorved ventilens ringformede ventilspalte øges med henblik på at øge ud-15 strømningen af overløbsvand 3a. Dette tryk i ringkammeret 20 virker på den del af membranens midterparti 5a, som understøttes af spindelen 8’s hoved 8a, som er dimensioneret med en så stor diameter, at det rager radialt uden for sædet 4. Dette bevirke enkelt sagt, at det tilgående 20 vandtryk får et større "stempel" at løfte, og at vandtrykket derfor kan overvinde det modsat rettede fjedertryk fra trykfjederen 9, således at der opnås den ønskede åbning mellem sædet 4 og membranen 5 og hermed en tilstrækkelig stor udstrømning af vand ved et overtryk på 25 10%. Baggrunden for sikkerhedsventilens virkemåde er, at trykfjederen 9 kollapser, når vandtrykket bliver større end 9 atø og en ukontrolleret vandmængde kommer ind i overløbet eller udløbet 7 via ringkammeret 20 og dettes udløbsåbning 20a. For at hindre dette, kan spindelens 8 30 bevægelse begrænses til en maksimal løftebevægelse på f. eks. 0,5 mm ved hjælp af et mekanisk stop. Dette muliggør en tilstrækkelig udstrømning af vand ved et tilladeligt overtryk på op til f. eks. 9,8 atø. Ved tømning af vandvarmerens tryktank er det ønskeligt at have et større 35 spillerum mellem membranen 5 og sædet 4, f. eks. 1,5 mm.10 When the water pressure rises above the opening pressure of 9 ato, for example 9.8 ato, ie. As mentioned above, due to the pressure build-up in the annulus 20, the membrane 5 will be lifted further from the seat 4, thereby increasing the annular valve gap of the valve to increase the outflow of overflow water 3a. This pressure in the annulus 20 acts on the portion of the central portion 5a of the diaphragm supported by the head 8a of the spindle 8, dimensioned so large that it projects radially outside the seat 4. This simply means that the incoming water pressure causes a larger "piston" to lift, and therefore the water pressure can overcome the opposite directed spring pressure from the compression spring 9, so that the desired opening between the seat 4 and the membrane 5 is obtained and thereby a sufficiently large flow of water at an overpressure of 25 %. The reason for the operation of the safety valve is that the pressure spring 9 collapses when the water pressure becomes greater than 9 ato and an uncontrolled amount of water enters the overflow or outlet 7 via the annulus 20 and its outlet opening 20a. To prevent this, the movement of the spindle 8 can be limited to a maximum lifting movement of, for example, 0.5 mm by means of a mechanical stop. This allows for sufficient outflow of water at a permissible overpressure of up to eg 9.8 ato. When emptying the water heater pressure tank, it is desirable to have a greater clearance between the diaphragm 5 and the seat 4, for example 1.5 mm.

Af denne grund er det mekaniske stop derfor fjedrende udført med et større fjedertryk end trykfjederen 9, således 8For this reason, the mechanical stop is therefore resilient with a greater spring pressure than the compression spring 9, thus 8

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som det opnås ved hjælp af gummibufferen 16.as obtained by the rubber buffer 16.

Gummibufferen 16 har således følgende funktioner: 5 1. Den støttér membranen 5 i området mellem fjederhuset 6 og spindelhovedet 8a, således at membranen uanset de tryk, der opstår, ikke går i stykker, hvis der opstår bankning. Gummibufferen 16 har f. eks. et spillerum 18 på 0,5 mm mod membranen 5's yderparti, samt et tilsvarende 10 spillerum 19 mellem gummibufferen 16' s nedre ende og spilhovedet 8a. Bufferlegemet 16 muliggør derved, at membranen og spindelens hoved 8a kan løftes 0,5 mm af overtrykket, mens det ved at understøtte membranen 5 hindrer, at trykfjederen 9 kollapser. Ved tømning af vandvarmeren 15 kan spindelen 8 og dermed membranen 5 imidlertid løftes ialt 1,5 mm fra sædet 4 ved hjælp af ovennævnte håndhjul 14 og sammentrykning af gummibufferen 16.Thus, the rubber buffer 16 has the following functions: 1. It supports the diaphragm 5 in the area between the spring housing 6 and the spindle head 8a so that the diaphragm does not break if knocking occurs, irrespective of the pressure. For example, the rubber buffer 16 has a clearance 18 of 0.5 mm against the outer portion of the membrane 5, and a corresponding clearance 19 between the lower end of the rubber buffer 16 and the gaming head 8a. The buffer body 16 thus enables the diaphragm and the spindle head 8a to be lifted 0.5 mm by the overpressure, while by supporting the diaphragm 5 prevents the compression spring 9 from collapsing. However, when emptying the water heater 15, the spindle 8 and thus the membrane 5 can be lifted a total of 1.5 mm from the seat 4 by means of the above handwheel 14 and compression of the rubber buffer 16.

Gummibufferen 16 bibringer spindelen 8 og dermed også 20 membranen 5 en nøjagtig styring, således at sikkerhedsventilen åbnes og lukkes korrekt.The rubber buffer 16 imparts precise control to the spindle 8 and thus also to the diaphragm 5 so that the safety valve is opened and closed properly.

I stedet for en gummibuffer kan der selvsagt anvendes en trykfjeder, men denne vil ikke kunne fungere på samme 25 gunstige måde som gummibufferen 16 med hensyn til centrering af trykfjederen 9, samt understøtning af membranen 5’s overside under forøgelse af trykket og eventuelt ven bankning.Instead of a rubber buffer, a compression spring can of course be used, but this will not work in the same favorable manner as the rubber buffer 16 for centering the compression spring 9, as well as supporting the upper surface of the diaphragm 5 with increasing pressure and possibly friend knocking.

30 De forskellige komponenter 8a, 19, 20 og 21 samvirker og kan varieres indbyrdes, hvorved følgende opnås:The various components 8a, 19, 20 and 21 cooperate and can be varied among themselves, thereby obtaining the following:

Spindelhovedet 8a's diameter kan f. eks. forøges for at opnå en større løftehøjde og derved øget gennemstrømning 35 af vandmængde eller vice versa. Sammen med gummibufferen 16 giver spindelhovedet 8a en fuldstændig støtte for membranen 5.For example, the diameter of the spindle head 8a may be increased to achieve a greater lifting height and thereby increased flow of water 35 or vice versa. Together with the rubber buffer 16, the spindle head 8a provides complete support for the membrane 5.

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DK 163374 BDK 163374 B

Ved at variere spillerummet 19 mellem gummibufferen 16 og spindelhovedet 8a kan den ønskede maksimale vandudstrømning ved maksimalt overtryk fastlægges. På grund af, at gummibufferen 16 kan sammentrykkes yderligere ved 5 hjælp af det’ nævnte håndhjul 14, opnås en tilstrækkelig stor løftehøjde af membranen 5 til at kunne tømme vandvarmerens tank. Der foreligger således et kontrolleret totrins fjedertryk.By varying the clearance 19 between the rubber buffer 16 and the spindle head 8a, the desired maximum water outflow at maximum overpressure can be determined. Because the rubber buffer 16 can be further compressed by means of the said handwheel 14, a sufficiently high lifting height of the diaphragm 5 is obtained to be able to empty the tank of the water heater. Thus, a controlled two-stage spring pressure is available.

10 Ringkammeret 20 mellem membranen 5's underside og ventilhuset 1 fastlægger sammen med kammerets udløbsåbning 20a den tilsigtede trykdifference mellem trykside og udløbsside og dermed den trykopbygning i ringkammeret 20, som er nødvendig for at hæve membranen 5 maksimalt fra sædet 15 4.10 The ring chamber 20 between the underside of the diaphragm 5 and the valve housing 1 together with the outlet opening 20a of the chamber determines the intended pressure difference between the pressure side and the outlet side, and thus the pressure build-up in the ring chamber 20 which is necessary to raise the diaphragm 5 maximum from the seat 15 4.

Den totale gennemstrømningsmængde kan forøges ved at forøge gennemløbet 21's diameter, men på grund af den hermed følgende større trykflade på membranens midterparti er 20 det da nødvendigt samtidigt at forøge trykfjederen 9's fjedertryk.The total flow rate can be increased by increasing the diameter of the passage 21, but due to the consequent larger pressure surface on the central portion of the diaphragm 20 it is then necessary to simultaneously increase the spring pressure of the spring 9.

Ved på rigtig måde at variere ovennævnte komponenter kan de krav, som i de enkelte lande stilles med hensyn til 25 sikkerhedsventilens funktion, opfyldes.By properly varying the above-mentioned components, the requirements set by the individual countries regarding the function of the safety valve can be met.

I det foregående er sikkerhedsventilens opbygning og funktion beskrevet, uden at dens overløb eller udløb 7 er forbundet med en slange eller et rør til et afløb eller 30 en kumme. Når en sådan slange eller et sådant rør 33 sluttes direkte til sikkerhedsventilens A's udløb 7, opstår der bankeproblemer på grund af den trykopbygning, der finder sted i udløbet 7 og slangen 33, og som bevirker, at membranen 5 løftes højere op fra sædet 4. Derved 35 strømmer der en tilstrækkelig stor vandmængde gennem sik kerhedsventilen, og trykket i det tilgående vand 3 falder til under åbningstrykket, hvorved sikkerhedsventilen påny 10In the foregoing, the structure and function of the safety valve are described, without its overflow or outlet 7 being connected to a hose or pipe for a drain or basin. When such a hose or pipe 33 is connected directly to the outlet 7 of the safety valve A, knocking problems occur due to the pressure build-up which takes place in the outlet 7 and the hose 33, which causes the diaphragm 5 to be raised higher from the seat 4. Thus, a sufficiently large volume of water flows through the safety valve and the pressure in the inlet water 3 falls below the opening pressure, whereby the safety valve again

DK 163374 BDK 163374 B

lukker. Dernæst øges trykket til over åbningstrykket, hvorved ventilen igen åbner, og der optræder, bankning.closes. Next, the pressure is increased to above the opening pressure, whereby the valve again opens, and there occurs, knocking.

Dette finder sted for alle ventiltypers vedkommende. For 5 at afhjælpe denne ulempe er der, som vist i fig. 2 og 3, anbragt en væskeslagsdæmper B mellem overløbsslangen/ -røret 33 og sikkerhedsventilen A's udløb 7. Denne væskeslagsdæmper B omfatter et til vand og luft indrettet kammer 32 med en indløbsåbning 32a for tilslutning af sik-10 kerhedsventilen A's udløb 7 og en udløbsåbning 32b for tilslutning til overløbsslangen/-røret 33. Kammeret 32 har en til luft beregnet øvre kammerdel L, som ligger i et højere niveau end ind- og udløbsåbningerne 32a, 32b, samt en nedre kammerdel V til vand. Kammeret 32 er, som 15 vist, fortrinsvis kugleformet med radialt modstående ind-og udløbsåbninger 32a, 32b. Udløbsåbningen 32b er for trinsvis mindre end indløbsåbningen 32a, og de nævnte åbninger ligger horisontalt flugtende med hinanden i væskeslagsdæmperen B's monterede tilstand. Det vil sige, at 20 væskeslagsdæmperen virker efter "vindkedelprincippet".This takes place for all valve types. To alleviate this disadvantage, as shown in FIG. 2 and 3, a liquid shock absorber B is located between the overflow hose / tube 33 and the safety valve A outlet 7. This liquid shock absorber B comprises a water and air chamber 32 with an inlet opening 32a for connecting the safety valve A's outlet 7 and an outlet opening 32 for connection to the overflow hose / tube 33. The chamber 32 has an upper chamber portion L, which is located at a higher level than the inlet and outlet openings 32a, 32b, and a lower chamber portion V for water. The chamber 32 is, as shown, preferably spherical with radially opposed inlet and outlet openings 32a, 32b. The outlet orifice 32b is incrementally smaller than the inlet orifice 32a, and said apertures are horizontally flush with each other in the mounted state of the fluid impact damper B. That is, the 20 fluid shock absorber works according to the "wind boiler principle".

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Claims

11 DK 163374 B

A safety valve for a water heater equipped with a pressure tank, which is adapted to open for overpressure in the pressure tank and comprises a valve housing (1) with an inlet (2) for pressure water and an outlet (7) for any overflow water, and a valve (4, 5, 8, 9) arranged between this inlet (2) and outlet (7) with an annular seat (4) in a passage (21) connecting the inlet (2) to the outlet (7), and a diaphragm (5) which, with its peripheral portion, is clamped between an annular breast in a valve insertion opening (22) arranged in the valve housing (1) and an end surface (6a) of a spring housing (6) screwed into this opening (22), 15, in which a spring-biased spindle (8) with a spindle head (8a) is arranged so resiliently against the upper part of the diaphragm (5a) of the diaphragm (5a) that its underside is resiliently pressed into abutment against the seat (4), in addition, an annular chamber (20) defined by the housing 20 (1) and the underside of the membrane (5) is arranged with a d the outlet (7) facing opening (20a) through which overflow water (3a) can flow out when an overpressure in the pressure tank and thus in the inlet (2) and the passage (21) lifts the diaphragm (5) from the seat (4) below the coil. An early build-up in the annulus (20) of a pressure which affects the outside of the seat (4) outside of the diaphragm (5) in such a way that this diaphragm is raised further from the seat (4), thereby increasing the annular gap between the valve that the outflow of overflow water (3a) 30 is correspondingly increased, and wherein the spindle (8) extending through a guide opening (10a) in the bottom (10) of the spring housing (6) is further surrounded by a pressure spring (9) which is located clamped between the bottom (10) and the radially projecting spindle head (8a) past the seat (4), known g-net in that the head portion (8a) of the spindle (8) and the central portion (5a) of the diaphragm (5) are interconnected connecting means (8b, 5b), that a resilient, compressed buffer body (16 ) which has a greater spring force than the compression spring (9) is arranged between a shoulder (17) in the spring housing (6) and the spindle head (8a) with an axially predetermined clearance 5 (19) relative to this or the shoulder (17). which corresponds to the maximum lifting height of the diaphragm (5) and that the spindle (8) is arranged so that it can be moved further axially against the spring force of the buffer body (16) by means (12, 14) arranged for this outside the spring housing. emptying the pressure tank. 10

Safety valve according to claim 1, characterized in that the compression spring (9) has a predetermined length and a predetermined spring pressure with as flat a spring characteristic as possible that the spring (9) is clamped with a predetermined distance between the bottom (10) of the spring housing (6) and the spindle head (8a), and that the spring of the spring housing (6) in the valve inlet opening (22) is limited by cooperating stops (6b, 11) arranged on the spring housing (6) and valve inlet respectively The outer end (11) of the ring (22), which serves partly to obtain the intended clamping force of the peripheral portion of the membrane (5) and partly the intended clamping force between the underside of the membrane (5) and the seat (4).

Safety valve according to claim 1, characterized in that the buffer body (16) is an annular rubber buffer which, with its outer wall and one end, abuts the inner wall and shoulder (17) of the spring housing (6) and the other end with respect to the diaphragm. (5) has a clearance (18) 30 corresponding approximately to the clearance (19) between the buffer body (16) and the spindle head (8a).

Safety valve according to claim 3, characterized in that the central opening (16a) of the buffer body (16), converges in the direction towards the spindle head (8a) and with its narrowest section is centered on the lower end of the compression spring (9), which in turn lies centered on the spindle (8). 13 DK 163374 B

Safety valve according to claim 1, characterized in that the upper end (8c) of the spindle (8) extends freely 5 through an opening (14a) in a handwheel (14) pivotally engaging the spring housing (6) with a circular shoulder (12) cooperating with an abutment (6c) on the spring housing (6), and said abutments (12 and 6c) comprising cooperatively inclined faces or optionally inclined faces and bosses to 10 via a stop washer (15) at the spindle end (18c ) by turning and consequent axial movement of the handwheel (14) to lift the spindle (8) and thereby the diaphragm (5) from the seat (4) for regulating the flow and for any emptying of the pressure tank. 15

Safety valve according to claim 1, characterized in that the cooperating connecting means (8b, 5b) are formed by a preferably threaded center bore (8b) in the head (8a) of the spindle (8) and a central pin formed on the side of the diaphragm (5). (5b) to screw into the bore (8b). 25 30 35