The helicopter traffic in connection with the production of petroleum off shore has given rise to strict requirements to the fire fighting systems disposed on the helipads of the in- stallations. Besides, it is expected that the requirements will be tightened, with, among other things, specifications that a possible fire shall be extinguished within a very short time, while at the same time the temperature at the fire area is to be kept down. Likewise, that the fire extin- guishing liquid shall be spread in the specified manner inde- pendent of the intensity of the fire and the prevailing weather conditions. Known fire fighting systems may consist

of a number of deluge guns disposed around the helipad, sprinkler system mounted into the helipad, or as a combina- tion of both deluge guns and sprinkler system.

Practice has shown that known systems for fire fighting, that be deluge guns or sprinkler systems, are absolutely not un- problematic in use. Tightened requirements to the fire fight- ing system will worsen the situation further. As for the del- uge guns, it may be mentioned as a defect that they are difficult to operate manually, because of high temperature close to the fire, the extinguishing liquid from the guns undesirably flushes other parts of the installation with burning petrol, the wind carries the extinguishing liquid away from the fire area, or that such guns hardly permit automatic operation in a fully satisfactory manner. As to sprinkler plants, it may be mentioned as a defect that known sprinkler nozzles are not capable of spreading the fire ex- tinguishing liquid in such amounts that the fire is extin- guished quickly enough, of keeping the temperature by the fire low enough, or of spreading the liquid to a sufficient height from and to the sides of the outlet of the sprinkler nozzle.

The main object of the present invention is to provide a de- vice by a sprinkler nozzle which is of sufficiently large ca- pacity for the sprinkler plant to be able to extinguish a possible fire within a very short period of time, while at the same time the temperature in the fire area is to be kept down. A further object is that the fire extinguishing liquid is to be sprayed up to a minimum height above, and to a mini- mum lateral distance from the outlet of the sprinkler nozzle.

This is realised by means of the present device by sprinkler nozzle, in which the particularity is that the pin of the

sprinkler nozzle is constituted by an inner sprinkler nozzle pin part which is fixed to the sprinkler nozzle housing, and an outer sprinkler nozzle pin part which is displaceably ar- ranged in the sprinkler nozzle housing. Furthermore, the sprinkler nozzle pin parts are arranged coaxially in the pas- sage in the sprinkler nozzle housing, so that the outer sprinkler pin part surrounds the inner sprinkler nozzle pin part. Thereby are provided sprinkler nozzles enabling the formation of sprinkler systems with a capacity of meeting the new and tightened requirements to fire protection of e. g. helipads. Likewise, the invention could eliminate the use of deluge guns. Other advantageous features of the invention ap- pear from the claims and of the specification.

In the following part of the specification, and with refer- ence to the accompanying set of figures, preferred embodi- ments of the invention will be explained in further detail, in which : Fig. 1 shows a schematic view of a vertical section through the present sprinkler nozzle in stand-by position ; Fig. 2 shows the same as Fig. 1, apart from the sprinkler nozzle being in an activated position ; Fig. 3 shows a schematic view of sections through the flange of the outer sprinkler nozzle pin part ; and Fig. 4 shows a schematic view of sections through the secur- ing part of the inner sprinkler nozzle pin part.

The sprinkler nozzle 1 which is shown in the set of figures, consists of a sprinkler nozzle housing 2 with a passage 3 for liquid. The sprinkler nozzle 1 shown is made up of three housing elements which may be connected to each other by means of threaded connections formed in the appropriate end of the respective housing element. A lower housing element-is formed with an external lock nut and with a length adjusted to e. g. the deck profile of a helipad comprising a sprinkler system for fire fighting. A lower end of each sprinkler noz- zle is connected to a respective pipe end of the piping of the sprinkler system for the supply of suitable liquid such as water, water with a foam concentrate (AFFF), etc. It is a matter of course that the sprinkler housing 2 may be formed in another manner than by the use of the three sprinkler housing elements shown.

The sprinkler nozzle pin of the sprinkler nozzle 1 providing actuation and sprinkling of the liquid supplied in the sprin- kler system, is disposed in the passage 3 in the sprinkler nozzle housing 2 and is constituted by an inner sprinkler nozzle pin part 4 which is fixed to the sprinkler nozzle housing 2, and an outer sprinkler nozzle pin part 5 which is displaceably arranged in the sprinkler nozzle housing 2. The sprinkler nozzle pin parts 4,5 are arranged coaxially in the passage 3 in the sprinkler nozzle housing 2, and in such a way that the displaceable outer sprinkler pin part 5 sur- rounds the fixed inner sprinkler nozzle pin part 4. The upper end of the inner sprinkler nozzle pin part 4 is at the level of the upper end of the sprinkler nozzle housing 2. The upper end of the outer sprinkler nozzle pin part is correspondingly at the level of the upper end of the sprinkler nozzle housing 2 when the sprinkler nozzle is in its non-activated position.

In the activated position the outer sprinkler nozzle pin part

5 is displaced preferably by 15 mm upwards from the upper end of the upper end of the sprinkler nozzle housing 2. The upper ends of the sprinkler nozzle pin parts have shapes that are adapted, among other things, to close the passage 3 when the sprinkler nozzle 1 is in its non-activated position.

To ensure that the outer sprinkler nozzle pin part may be displaced expediently in the passage 3 in the sprinkler noz- zle housing 2, the lower part of the outer sprinkler nozzle pin part 5 is formed with a flange 6 facing, and adapted to bear against, the side wall 15 of the passage 3 of the sprin- kler nozzle housing 2. Further, the flange 6 has at least two beads 7 bearing against the side wall 15 of the sprinkler nozzle housing 2, so that the flange 6 will not block the passage 3. The passage 3 of the sprinkler nozzle housing 2 is formed with a shoulder 16 arranged above the flange 6. The shoulder 16 constitutes an abutment for the flange 6 when the sprinkler nozzle 1 is activated, so that the outer sprinkler nozzle pin part 5 is displaced in the sprinkler nozzle hous- ing 2. The inner sprinkler nozzle pin part 4 is fixed to the sprinkler nozzle housing 2 by means of a securing element 10 extending between the side wall 15 of the passage 3 in the sprinkler nozzle housing 2 and preferably the lower end of the inner sprinkler nozzle pin part 4. The securing element 10 may be secured to the side wall 15 of the sprinkler nozzle housing 2 by means of a threaded connection. Said threaded connection may be formed in the respective end of the two lower housing elements. To prevent blocking of the passage 3, the securing element 10 has at least one bore 11.

The sprinkler nozzle 1 intentionally achieves the horizontal and vertical spreading of the liquid supplied, by means of deflecting faces 8,9, 12 which are formed at the upper ends

of the sprinkler nozzle pin parts 4, 5. The deflecting faces 8,9 of the outer sprinkler nozzle pin part 5 are at an out- ward or inward angle from/towards the inner sprinkler nozzle pin part 4, as the deflecting face 8, sloping outwards from the inner sprinkler nozzle pin part 4, preferably extends in a curved line, and the deflecting face 9, sloping inwards to- wards the inner sprinkler nozzle pin part 4, preferably ex- tends in a straight line, while the deflecting face 12 of the inner sprinkler nozzle pin part 4 is sloping outwards towards the outer sprinkler nozzle pin part 5, the deflecting face 12 preferably extending in a straight line. The upper end of the sprinkler nozzle housing 2 is formed with a deflecting face 17 sloping outwards from the sprinkler nozzle pin parts 4,5, the deflecting face 17 preferably extending in a curved line.

The deflecting face 17 works partly as a bearing and sealing surface for the deflecting face 8 of the outer sprinkler noz- zle pin part 5, and partly to increase further the effect of the sprinkling of liquid. It is a matter of course that the deflecting faces 8,9, 12,17 may have an extent deviating from what is shown in the set of figures, so that the liquid may be directed in a way adjusted to the relevant application of the sprinkler nozzle.

Further, the sprinkler nozzle pin parts 4,5 are of such form that the respective portions of the sprinkler nozzle pin parts 4,5 below the deflecting faces 8,9, 12 form channels 13,14 for liquid in the passage 3 of the sprinkler nozzle housing 2. The channel 13 is formed between the lower por- tions of the sprinkler nozzle pin parts 4,5, and the channel 14 between the lower part of the outer sprinkler nozzle pin part 5 and the side wall 15 of the passage 3 in the sprinkler nozzle housing 2.

The present sprinkler nozzle is activated in the way that the liquid, which is supplied to the sprinkler nozzle, passes through the bores 11 of the securing element 10 of the inner sprinkler nozzle pin part 4, and presses against the lower face of the flange 6 and the end surface of the outer sprin- kler nozzle pin part 5, so that the outer sprinkler nozzle- pin part 5 is displaced upwards until the upper face of the flange 6 abuts the shoulder 16 of the passage 3 in the sprin- kler nozzle housing 2. Thereby the outer sprinkler nozzle pin part 5 is brought into a position allowing the liquid to pass freely in the passage 3 through the bore 11, the openings in the flange 6 created by the beads 7, the channels 14,15 and to be deflected by the deflecting faces 8,9, 12,17 at the upper end of the sprinkler nozzle.

In the above is specified, for reasons of simplicity, that the sprinkler nozzle is integrated in a sprinkler system dis- posed in helipads. Since the present sprinkler nozzle may be used in any sprinkler system, the above reference to the helipad must only be understood as an illustrating example.

Further, with a water pressure of 7 bars, the sprinkler noz- zle could spread the liquid horizontally at least 6, 5 m radi- ally outwards from, and to a height reaching 7 m from the outlet of the sprinkler nozzle. The so-called horizontal wa- ter volume is then at least 140 1/min, and the vertical water volume at least 200 1/min. Even by a wind force up to moder- ate gale the sprinkler nozzle could reach a height of at least 6 m. It is to be noted here that vertically the water volume may be regulated by adjusting the point of location of the flange 6 of the outer sprinkler nozzle pin part 5, and thus the lifting height of the outer sprinkler nozzle pin part 5, which affects the volume of the flow through the channel 13 between the sprinkler nozzle pin parts 4, 5.