GB2315809A - Door closer for the non-fire side of a fire-door safety installation - Google Patents

Abstract

To accommodate a pressure increase in hydraulic damping fluid in a door-mounted door closer, when the fluid is expanded by heat conducted through the door, a diaphragm 132 is moved into air cavity 136 when fluid pressure overcomes the bias of spring 131. The spring may be replaced by a pin which is sheared by a piston, and the diaphragm may be located at a side of the closer. The moving diaphragm may be pierced by a stationary spike.

Description

2315809 DOOR CLOSER FOR THE NON-FIRE SIDE OF FIRE-DOOR SIF-",nV TNSTAI AM

A.LLATION This invent-4on relates (generally to hydraulic fluid damped door closers and more -particularly to f ire resistant door clcsers incorporating features which discourage transfer of _4'-'re through a fire door.

Fire doors are designed to protect against passage of -f ire frcm one room tc anotter in a building. in the U.S., the National -.--;re Prczecmion Association Promulgates conszructicn and -Lnszallation standards for ire doors and windows as a zublicaticn, "7PA 80.

I,- - Listed fire doors are classified J;Ln twelve cazegor4es, and fi protecticn of an opening depends upon tte use cf a listed f4re door, a listed frame, listed door hardware, and a listed door control device as smecifled under each door type. Fire classifications for buildings are specified in madel building codes, government regulations, and state and local building codes. Fire door classifications are expressed in hourly ratings according t t to the Standard for Fire Tests of Door ssemblies UL 10B, ANST A2.2, ASTM E - 152, CSFY. 43.7, C;_N4-S!04 A 2), 'BC 43-2-19-1 2.

(ULC-S b 10- and NFPA 25 The classifi-c-ations are deter-mined by exposing the "Jons, and doors to f ire testing under standard ccndithourly razings in icate the duration of exmosure which the door can withstand, such as 4, 3, 2, 1 112, 1, 3/4 hours, and 30 or 20 minutes. It is per=issible to test a fire door with snecial hardware and installation. This is usually done by door manufacturers who wish to establish a fi--e rated door, frame, door control, and hardware cc-,,,binatiJ--n which 2an be specified in a building -0 contract. llt should be noted that, although there are several very similar 4Jre dcor assembly tests in use h- is no sinale -international throuchouz the wor Z, t-re fire test standard.

Generally, fire doors must be maintained closed and latched or must autcmatically close and latch under a broad ranae of -Fire exposure conditions in order tc properly serve tIL-leir fire protective function. Thus, the door control device must assure that the door closes after it has been opened, and the latch must maintain the door latched. Tcday, --,osz flire door tests are cerfor=ed without a door control device, or, if included, the door control is mounted on the fire side of the door.

Most currently used door contrcl devices employ hydraulic damping technology to control opening and closing speed of the door. The hydraulic fluid is commonly a petroleum based oil which is relatively inexpensive, plentiful, non-corrosive, and compatible with a wide range of metals and other materials.

However, petroleum oils have an auto-ignition temperature ranging between approximately 500 and 750 degrees Fahrenheit (260-399C) and may contribute to the spread of the fire, if exposed to high temperatures, even when the door control device is mounted on the non-fire side of the door.

Within a few minutes after a fire begins, assuming it is adjacent to a fire door, the temperature of the door control device on the non-fire side of the door begins to increase by conduction through the door. This causes the hydraulic fluid to expand, to leak around the seals of the door control device, and to run down the door. Approximately 10 to 15 minutes after the fire starts, the temperature on the non-fire side of the door is high enough to cause auto-ignition of the leaking fluid. Even though the door and frame assembly may have a fire rating of 2 hours, or more, the fire has transferred through the door in less than 15 minutes.

According to the present invention there is provided a door control device for use on a non-fire side of a fire-door mounted in a door frame in a fire-door safety installation, comprising a door closer assembly filled with a hydraulic damping fluid for attachment to said non-fire side of said fire-door by at least one fastener; a door control arm for pivotally connecting to said door frame at a first end and to said door closer assembly at a second end, and means, in said door closer assembly, for providing pressure compensation, the means for providing pressure compensation including a diaphragm mounted within a low pressure volume inside said door closer, such that, when heated by contact of the door closer with the fire door, the expanding hydraulic is damping fluid causes the diaphragm to occupy the low pressure volume, thereby relieving thermal expansion pressure therein.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made by way of example, to the accompanying drawings, in which:

Fig. 1 is a fragmentary schematic elevational page 7 follows partially sectional view of a door control device - embodiment; illustrating tie fusible hcll.

Fig. 2a and Fig. 2b are fragmentary schematic plan views showing the biased door control arm feature applied to two different types of door control arms; Fig. 3a, 2b, 2c, 2d, and le are fragmentary schematic elevational partially secticnal views of a door control device 4Lnccrporat-Jng three alternative pressure compensation feazures and two variations thereof; and io Fig. 4 is a fragmentary partially sectional elevation view illustrazing the insulation feature of the present invention.

Ideally, all that _Js required for a door control i5 for use an the non-fire side of a fire door is a hydraulic fluid which is completely impervious to heat, pressure, or combinations thereof which nay cause auto- ignition, fluid leakage, viscosity degradation, boiling, or any of a myriad of breakdown mechanisms. In 20 reality, virtually any hydraulic fluid can be made to ianite under some conditions, and Ito differing extents, all fluids cont--.bute to corrosion or other attack unon 1-he seals and =her c--m.mcnents. However, depending on the compositions of seals and other parts of the door control, a fluid having adequate ccmDat..4,.bilitv of properties can usually he found.

There are -four ar-cuns of fire resistant fluids currently available f-cr hydraulic applications. These are generally categorized according the relat4ive amounts of oil and war-er ccnzained, general -resistance to -O temnerature var-Jaz-4cn, with seal materials, 4on a:'- ed, and resistance to fluid wear mrc--ecz 1-r- breakdown. Althougn all zresenzlv available fluids will burn under cerzain c--nd-4---ns the fire hazard '.,.as been reduced in fire resistant fluids zc a sufficient dearee -15 -c render them accenzable 'n aDmrcmr4ate an:lications.

Acccrding to one standard of -f ire saf ety, Group fluids include inhibited wazer-alycol fluids with other additives, such as basic amine domed diettivlene glycol, diethylene polyglycol, pclvalkaline glycol, and mixtures thereof. Thev do not generally attack ordinary packings and seals used in pumps and valves. Loss c..E water content in normal use tInrough evaporation Jis reflected in an increase in viscosity of the fluid and ccnseauent _N improper function of the hydraulic device. This serves as an automatic safeguard, in that equipment becomes inoperable before the fire hazard of the material is significantly increased by the decrease in water content.

Group II includes synthetics, such as phosphate-ester fluids, phosphate-ester based fluids, and halogenated hydrocarbon based fluids. These are stable homogeneous compounds in which characteristics do not change appreciably throughout their operational life.

Since regular pump seals, packings, and gaskets may be attacked by these fluids, they should be replaced with materials that will not be so affected.

Water-oil emulsions are included in Group III. They present considerably lower fire hazard than all mineral oil, but because of proportions, the emulsion must be carefully maintained. Separation of oil from the emulsion may be caused by contamination of the system by chemical cleaners or solvents, temperatures above 150 degrees F. (661C) or below 50 degrees F. (10C), high pressure (1500 - 2000 PSI - 10342.5 - 1379OkN/m2), and prolonged equipment shutdown or drum storage. It is, therefore, very important to adhere strictly to the manufacturers instructions regarding use and maintenance of the emulsion.

Grouio IV are the hiq,ft water base f luids containing 70%, or more, of water. They have excellent fire resistance. They are, generally, made by adding synthetics or soluble oils za water. Because of the high water content, stric"t adherence to the manufacturer's instructions is very iMpor--ant to avoid premature comzonent wear or failure.

In the preferred embodiment of the present invention, the water-glycc! fluids of Group I were 7 C) selected due to tteir cverall combination of properties. They are not compatible wJLzh lead, tin, zinc, cadmium, or magnesium and will cause ccrrosion and will degrade in contact with these materials. However, the materials from which door controils are made (aluminum, copper, brass, cast iron, steel) are not corroded by contact with the water- glycol mixmures. 7_n addition, standard seal materials such as rubbers, Buna N, Buna S, and Neoprene, silicones, and PTFEs work well with water- glycols because they do not absorb water. Thus, -mosz water resistant sealants are suitable for applications with the water-glycol family of fluids. For lubrication, only greases having good water tolerance such as lithium, calcium, and aluminum complex greases should be used. Water- glycol fluids are safe for handling since they have no nitrosamines, nitrates, nor any other suspected or established carcinogens. The composition is 41% water and a balance of diethylenepolyglycol with a basic amine corrosion inhibitor.

it should be noted that, for most standard fire door applications, the Group I water-glycols are adeUate in all respects; however, there are also applications for which fluids from Groups!I,!!I, or iV will be preferred due to special materials or service requirements. in any io case, the choice of fluid will be made by considering at least the factors enumerated above with respect to the preferred embodiment.

As earlier stated, under the right conditions, any of the fire resistant fluids will ignite and burn. Thus, i5 it is clear that, although the preferred embodiment serves the purpose of discouraging transfer of fire through a fire door, it does not fully eliminate the possibility of such. Additional features are provided which, when taken in conjunction with the fire resistant fluid and/or with each other, markedly improve the resistance of a fire door assembly to flame transfer.

Referring to Fig.!, an important feature is apparent. A door io is hung wit.hin a door frame 40 to pivot an hinges which are not illustrated. A door the door 10 control device 20 is mounted to the face of '" and is concealed and mrczected by c--ver 21. Door control pinion 22 extends through. cover 21 and engages one end of door control arm 30, Ithe other end of which is pivotally attached to door -Izame u_Jvct 42. Door control device 20 is attached to the door iO bv means of one or more 0:rom a material which is kasteners 15 which are made 4- ia structurally strong enough to supporz the door control device 20 but -is also at a temnerazure lower than the auzc-icnit-Jon poinz cr flash point of the hydraulic fluid used in the door conzr-cl device. Since it is mounted on the non-fire side of the door 10, the door -y ccnduczJ 1:z control device 420 is heated solely.on of heat hraugh door 10; there, lusible fasteners (or fastener) 15 are heated before the door control device 20 fluid in the which is itself heated before the hydraulic device. As a result of this heating sequence, the fusible fasteners 15 are assured of reaching their melting point and releasing door control device 20 from its attachment to the door 10 before the hydraulic fluid can heat enough to begin leaking, due to pressure induced by thernal expansion, and certainly before the fluid reaches its auto--gni--ion temnerature.

Upon -.lie fusion release of fasteners 15, door control device 20 will sag on door control a= 30 due to its weight and will consequently pivot away -from contact with 1 with t.he door!0. This breaks the contact he door Ocr canduction heating and, for all intents and 10 needed f purposes, rmakes further heating of 4Che door control c fluid very unlikely.

device 20 and its hvdraul.

2a & 2b illustrate another feature c--- the included as an additional assurance of evice 20 and 0 deccucl.-ng between z-.e door control - Lhe door!C) unon fusion czE the fasteners of 'Fig. 1. -- In e door control arn, 30 of Fig. 2a is -..-.iacie up of an end 31 attached, at one extreme, to door fra=e pivot 42 an door Lrame 40 and, at the other extreme, z-another end 32 by a connect-ina pivot End -2 is also connected to door control device 20 pinion 224. When released by fusion of 'the fasteners, or by any =her means, bias springs 36 and -14 act between ar:n 31 and pJvoz 42 and between a=. 22 and arm 31 at pivot ii, resnecz-4vely, to make the door control device swina away -fro= the door in response to the door control arm 30 seeking a position pervendicular to the door frame 40. This further assures ---eak contact with that the door control device 20 will b- h ion heatinc fire door 10 and thereby avoid furt-er conduct- -ion of and auto ignit, he hydraulic oil, even with some frictional drag to overcame.

The illustration off 2b shows another t, ype of door control arm 35 made up of a single member connected to pinion 22 at the output of door control device 20, at one end, and pivotally c--nneczed, at the other end, to a slide 4.11 which slides in a straight track 45 along door frame 40 wnen the door is moved. Upon release of door control device 20 frc-,n, door io, biasing spring 46 causes -.0 arm 35 to seek a perpendicular orientation with respect to the door fr-ame 40, zherebv moving door control device 20 to its maximum distance orcn, the door io.

The desired resull-t is achieved with. either type of door control arm, i. e., the door control is separated from the door, -which is heating, and the hydraulic fluid within the door control -s zrozeczed frcm further conduction heating.

The features illustrated in Figs. 3a - 3c provide pressure compensation for decreasing the chance of hydraulic damping fluid leaking from the door control device when the door ccnzrzl is heated. For proper door control function, the device must be able to sustain a certain level of fluid pressure without leaking; and, since it is ideally corpletely -1-illed with 'luid at room temperature, any increase in fluid temperature results in a rapid pressure increase. Seals are employed to sustain operating pressure requirements together with pressure variations due to nc=al temperature fluctuations. The pressure limits for the seals of the door control device must not be exceeded L-f -',,-zakaae and fire transfer due to auto-ignition is to be avoided.

-'0 Fig. 3a shows a pressure cc-mmensation device featuring a spring whicn, provides a preload just f -a below the pressure limit fcr the seals c. -he door control or closer. For -::his embodiment, the door control 120 consists of a reQular closer body 125 and an end iplug f the niston c-linder. Plug 130 has a 130 at the end c. body 135, a cavity 136 within the body, a preload spring 131 within the cavity, a diaphragm, 1-12 at the mouth of the cavity, and a preload retainer spider 133 over the diaphragnto retain it in place while permitting fluid access to the diaphragm in front of piston 126. Except for the cavity 136, which contains air, the entire closer 120 is filled with hydraulic fluid. When the fluid pressure exceeds the preload of spring 131, diaphragm 132 moves into cavity 136, thereby allowina the fluid to expand to relieve pressure, as the temperature increases, is prevents and sparing the seals of the closer 120. Th fluid leakage together with the attendant fire risk.

In Fig. 3b, closer 160 con sists of regular closer body 125 and end plug 170. End plug 170 comprises a plug body 177, which has a cavity 178, a post 171 upon which a piston 175 is fitted for sliding but secured by a shear pin 172, and a diaphragm!76 sandwiched between piston or sealing cavity 178 away and a preload spider!33 from the fluid which fills the closer bodv. Shear pin 172 is strong enough to withstand the pressure I-normal door closer fluctuations associated wit., overation; however, if the closer is expased to excessive heat conducting through the fire door, the resulting thermal expansion of the fluid will increase hydrostatic pressure within the closer. When a pressure exceeding the preload limit (pressure limit for the seals) is reached, shear pin 172 fails, piston 175 moves leftward on post 171, and the hydrostatic pressure is relieved so no fluid leaks from the closer 160. Here, as in the embodiment in Fig. 3a, the closer body is completely filled with fluid, and only the cavity of the end plug body contains air.

zFig 3c has a different pressure absorbing arrangement. Here the pressure compensating plug assembly 150 is similar in design to that shown in Fig 3a (130) but is installed in the atmospheric pressure portion of closer 140 which contains the springs. A th a regular closer regular end plug 122 is used along wit body 125, and only plug assembly 150, installed in threaded hole 11-5 is di.,"-lerent. Elevated pressure is neither necessary nor desired in that martion of closer .0 1420 since'pressure in that region does not contribute to cont=l of the door. Excent -0or the ability to make plug assembly i50 somewhat less rugged than end plugs 130 and 170, this arrancement. functiOns in the same way as those of Figs. 3a and 2b. Of ccurse, the required cavity is volumes for the t,l-lree clua assemblies will be determined by consideration c,-' the size of the closer, fire door rating, volume of hydraulic -fluid, ty pe of fluid, closer operating pressure, seal materials, and seal pressure limits.

one of two final embodinenzs of the invention is illustrated in Fig. 3d and is a simple variation of those embcdiments already illustrated in Figs. 3a-3c. In this case, pressure compensating plugs 130, 170, and 150 are each fitted with a diaphracrm. piercing project4on 200.

k, The projection 200 is spaced from the diaphragm 132, 176, 156 sufficiently to permit the diaphragm to deflect enough to accommodate fluid expansion due to increase of temperature to 200OF (93.3IC) or other appropriate limit.

Deflections greater than that cause the diaphragm to be ruptured by the projection and the fluid to be safely drained away from the door in a closed conduit 205. The same function can also be provided in the pressure compensating plugs 130, 170, 150 by a resettable pressure relief valve 225, as illustrated in Fig. 3e, opening into the closed conduit 205; however, in that case, the pierceable diaphragm 132, 176, 156 would be replaced by the pressure relief valve 225.

Fig. 4 illustrates another feature for use alone or in conjunction with one or more of the previously described features. As in Fig. 1, a door 10 is mounted in door frame 40 and is controlled by door closer 20 through door control arm 30 which connects between the output spindle of closer 20 and door frame pivot 42. In this case, insulator 100 is interposed between door 10 and closer 20 to reduce its heating rate. Depending upon the insulating value of the insulator 100, that may be all that is needed for preventing fire transfer through the fire door.

Use of fire resistant damping fluid alone would serve the purpose of preventing or retarding the transfer of fire to the non-fire side of a fire door. However, most if not all fire resistant fluids can become fln=n le under conditions which cause the non-inflammable components to evaporate or otherwise deteriorate. Therefore, the additional features disclosed herein are advantageous in that they each enhance the fire resistance of a fire door assembly which incorporates a door control or closer with these features. If they are used in combination, they can render a door control device "fire-proof" rather than fire resistant in a fire door assembly.

is The present door closer is also shown and described in co-pending applications numbers GB-A-2 289 311, GB-&^- q-71-7,-77.,, and GBAt.

GB-A-2 289 311 discloses a door closer device for use on a non-fire side of a fire-door mounted in a door frame in a fire-door safety insta-11ation, comprising a door closer assembly filled with a hydraulic damping fluid for attaching to said non-fire side of said fire door by at least one fastener,.with the door closer assembly made from materials selected for compatability 9 with a fire resistant fluid; a door control arm pivotally for connection to said door frame at a first end and to said door closer assembly at a second end; and said hydraulic damping f.luid comprises a firelresistant hydraulic fluid.

GB q-7i-717-77.-discloses a door control device for use on a non-fire side of a fire-door mounted in a door frame in a fire-door safety installation, comprising a door closer assembly filled with a hydraulic damping fluid for attachment to said non-fire side of said fire door by at least one fastener; a door control arm for pivotal connection to said door frame at a first end and to said door closer assembly at a second end; and said at least one fastener being made from a material which has a melting point lower than an auto-ignition temperature for said hydraulic damping fluid.

GB f 71-7,q-Z-Z. discloses a door control device for use on a non-fire side of a fire-door mounted in a door frame in a fire-door safety installation, comprising a door closer assembly filled with a hydraulic damping fluid for attachment to said non-fire side of said fire-door by at least one fastener; a door control arm for pivotally connecting to said door frame at a first k^ end and to said door closer assembly at a second end, and meanp for limiting fluid pressure in said door closer, 1 such that, when heated by contact of the door closer with the fire door, the means for limiting fluid pressure permitting the expanding hydraulic fluid to drain away from said fire-door in a closed conduit.

2-0

Claims (9)

CLAIMS:

1 A door control device for use on a non-fire side of a fire-door mounted in a door frame in a fire-door safety installation, comprising a door closer assembly filled with a hydraulic damping fluid for attachment to said non-fire side of said fire-door by at least one fastener; a door control arm for pivotally connecting to said door frame at a first end and to said door closer assembly at a second end, and means, in said door closer assembly, for providing pressure compensation, the means for providing pressure compensation including a diaphragm mounted within a low pressure volume inside said door closer, such that, when heated by contact of the door is closer with the fire door, the expanding hydraulic damping fluid causes the diaphragm to occupy the low pressure volume, thereby relieving thermal expansion pressure therein.

2. A door control device according to claim 1, further comprising biasing means for causing said door control arm to seek a perpendicular orientation with respect to said door frame when the second end of said arm is free.

11

3. A door control device according to claim 1 or 2, further comprising means for thermally insulating said door closer assembly to inhibit heat transfer from said fire door to said door closer assembly.

1

4. A door control device according to claim 1, 2 or 3, wherein said hydraulic damping fluid comprises a fire resistant hydraulic fluid.

5. A door control device according to claim 4, wherein said fire resistant hydraulic fluid is selected from a group consisting of inhibited water-glycol fluids.

6. A door control device according to claim 4, wherein said fire resistant hydraulic fluid is selected from a group consisting of synthetic fluids.

7. A door control device according to claim 4, wherein said fire resistant hydraulic fluid is selected from a group consisting of water emulsions of mineral oils.

B. A door control device according to claim 4, wherein said fire resistant hydraulic fluid is selected from a group consisting of high water base solutions of synthetics and soluble oils.

9. A fire-door mounted in a door frame in a fire-door safety installation, there being a door control device according to any one of the preceding claims mounted on the non-fire side of the fire-door. 5