GB2120934A

GB2120934A - Release member for a fire sprinkler installation

Info

Publication number: GB2120934A
Application number: GB08311450A
Authority: GB
Inventors: Ernst Landsberg; Rolf Manz; Roy Rainer
Original assignee: Walther and Co AG
Current assignee: Walther and Co AG
Priority date: 1982-05-28
Filing date: 1983-04-27
Publication date: 1983-12-14
Also published as: DE3220124A1; GB8311450D0; GB2120934B; DE3220124C2

Abstract

A release member (1) for a sprinkler for a fixed fire extinguisher installation, the release member containing a liquid (5) that is intended to burst the glass vessel (2) containing it upon heating thereof, there being a liquid displacement member 6 consisting of a material with a heat-absorption capacity which is smaller than the heat- absorption capacity of the liquid in the liquid in order to enable the liquid more quickly to assume the temperature which is necessary to burst the vessel. <IMAGE>

Description

SPECIFICATION Release member for a fire sprinkler installation This invention relates to a release member for a sprinkler for a fixed fire extinguisher installation.

A known release member, which consists of a small glass vessel filled with a liquid, holds a valve plate or disc of the sprinkler in a closed position.

Such sprinklers have been known for many decades.

In the event of fire, the glass wall of the vessel is heated by the fire, which wall in its turn heats the liquid. Because of the absorption of heat, the liquid expands and thereby exerts from inside an exploding or bursting pressure on the glass vessel.

The glass vessel has to have a certain wall thickness, in order thereby to withstand the mechanical pressure which is normally necessary for sealing the sprinkler. The thicker the glass wail of the release member, then increasingly longer is the time period which is necessary for heating the liquid therein to explosive pressure temperature. In order to shorten this time, the wall thickness of the glass vessel has generally been made increasingly thinner but it is not possible for the glass wall to be made too thin, for strength reasons.

According to the present invention, there is provided a release member for a spinkler for a fixed fire extinguisher installation, the release member consisting of a glass vessel filled with a liquid for bursting the vessel upon heating thereof, the release member being intended normally to close the sprinkler, wherein a liquid displacement member is arranged inside the glass vessel in the liquid, which displacement member consists of a material with a heat-absorption capacity which is smaller than the heat-absorption capacity of the liquid.

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 drawing, in which the single Figure is a diagrammatic sectional side view of a release member for a sprinkler for a fixed fire extinguisher installation.

The drawing shows a release or sprinkler initiating member 1 which consists of a small closed glass vessel 2 having a certain wall thickness 3. A liquid displacement member 6 is arranged within the glass vessel 2, which member 6 consists of a material having a heat-absorption capacity which is smaller than the heat-absorption capacity of a liquid 5 also in the vessel 2. The displacement member 6 can, for example, consist of a synthetic plastics material such as polytetrafluoethylene. The displacement member 6 floats freely inside the vessel 2 in the liquid 5. After introducing the liquid 5 and fitting the displacement member 6, an end 4 of the vessel 2 is sealed, thereby trapping the usual air bubble indicated at 7.

The ratio between the volume of the liquid 5 and the volume of the liquid displacement member 6 can be 1:1 to 1:5 and is preferably 1:3.

With this construction, the volume of the liquid 5 is substantially reduced as compared with the prior art, with unchanged mechanical strength of the small glass vessel 2. The smaller quantity of liquid is therefore more quickly able to assume the temperaturn which is necessary for the bursting of the glass vessel 2. Consequently, in the event of a fire, a sprinkler incorporating a release or initiating member 1 constructed according to the invention is opened more quickly than the known sprinklers without displacement members.

1. A release member for a sprinkler for a fixed fire extinguisher installation, the release member consisting of a glass vessel filled with a liquid for bursting the vessel upon heating thereof, the release member being intended normally to close the sprinkler, wherein a liquid displacement member is arranged inside the glass vessel in the liquid, which displacement member consists of a material with a heat-absorption capacity which is smaller than the heat-absorption capacity of the liquid.

2. A release member according to claim 1, wherein said displacement member consists of a synthetic plastics material.

3. A release member according to claim 2, wherein said synthetic plastics material is polytetrafluoethylene.

4.A release member according to claim 1,2 or 3, wherein said displacement member floats in said liquid.

5. A release member according to any one of the preceding claims, wherein the ratio between the volume of the liquid and the volume of the displacement member is 1:1 to 1:5.

6. A release member according to claim 5, wherein said ratio is 1:3.

7. A release member according to any one of the preceding claims, wherein said displacement member consists of several parts.

8. A release member for a sprinkler for a fixed fire extinguisher installation, substantially as hereinbefore described with reference to the accompaying drawing.

9. Afixed fire extinguisher installation incorporating a sprinkler having a release member that is according to any preceding claim.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Release member for a fire sprinkler installation This invention relates to a release member for a sprinkler for a fixed fire extinguisher installation. A known release member, which consists of a small glass vessel filled with a liquid, holds a valve plate or disc of the sprinkler in a closed position. Such sprinklers have been known for many decades. In the event of fire, the glass wall of the vessel is heated by the fire, which wall in its turn heats the liquid. Because of the absorption of heat, the liquid expands and thereby exerts from inside an exploding or bursting pressure on the glass vessel. The glass vessel has to have a certain wall thickness, in order thereby to withstand the mechanical pressure which is normally necessary for sealing the sprinkler. The thicker the glass wail of the release member, then increasingly longer is the time period which is necessary for heating the liquid therein to explosive pressure temperature. In order to shorten this time, the wall thickness of the glass vessel has generally been made increasingly thinner but it is not possible for the glass wall to be made too thin, for strength reasons. According to the present invention, there is provided a release member for a spinkler for a fixed fire extinguisher installation, the release member consisting of a glass vessel filled with a liquid for bursting the vessel upon heating thereof, the release member being intended normally to close the sprinkler, wherein a liquid displacement member is arranged inside the glass vessel in the liquid, which displacement member consists of a material with a heat-absorption capacity which is smaller than the heat-absorption capacity of the liquid. 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 drawing, in which the single Figure is a diagrammatic sectional side view of a release member for a sprinkler for a fixed fire extinguisher installation. The drawing shows a release or sprinkler initiating member 1 which consists of a small closed glass vessel 2 having a certain wall thickness 3. A liquid displacement member 6 is arranged within the glass vessel 2, which member 6 consists of a material having a heat-absorption capacity which is smaller than the heat-absorption capacity of a liquid 5 also in the vessel 2. The displacement member 6 can, for example, consist of a synthetic plastics material such as polytetrafluoethylene. The displacement member 6 floats freely inside the vessel 2 in the liquid 5. After introducing the liquid 5 and fitting the displacement member 6, an end 4 of the vessel 2 is sealed, thereby trapping the usual air bubble indicated at 7. The ratio between the volume of the liquid 5 and the volume of the liquid displacement member 6 can be 1:1 to 1:5 and is preferably 1:3. With this construction, the volume of the liquid 5 is substantially reduced as compared with the prior art, with unchanged mechanical strength of the small glass vessel 2. The smaller quantity of liquid is therefore more quickly able to assume the temperaturn which is necessary for the bursting of the glass vessel 2. Consequently, in the event of a fire, a sprinkler incorporating a release or initiating member 1 constructed according to the invention is opened more quickly than the known sprinklers without displacement members. CLAIMS

6. A release member according to claim 5, wherein said ratio is 1:3.