Fire-stop Wraps and Collars with Intumescent Materials

Available online at www.sciencedirect.com

ScienceDirect Procedia Engineering 172 (2017) 961 – 968

Modern Building Materials, Structures and Techniques, MBMST 2016

Fire-stop wraps and collars with intumescent materials – performance comparison Bartłomiej Sędłaka,*, Paweł Sulika, Daniel Izydorczyka, Marek Łukomskia a

Building Research Institute, Fire Research Department, Ksawerów 21 St., 02-656 Warsaw, Poland

Abstract In the event of a fire in building, the places where installations penetrate may be the ones where the fire easily enters adjacent rooms. Therefore, in locations where pipes divide requiring a certain fire resistance class, their passage must be sealed in a way that provides at least the same fire resistance as barrier. The paper describes the main issues related with the fire safety of pipe penetrations sealed with use of fire-stop wraps and collars with intumescent materials. It includes fire resistance tests methodology and general principles of fire resistance classification of the elements. Moreover, the performance comparison of plastic pipes sealed with use of wraps and collars, based on the temperature rises on the unexposed surface of the elements tested in the reinforced concrete floor has been presented. © Published by Elsevier Ltd. This © 2017 2016The TheAuthors. Authors. Published by Elsevier Ltd.is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of MBMST 2016. Peer-review under responsibility of the organizing committee of MBMST 2016 Keywords: glazed partition; aluminium profile; insulation insert; fire resistance; fire integrity; fire insulation.

1. Introduction In the event of a fire in building, the locations where installations divide may be the points where the fire easily enters adjacent rooms. Therefore, in locations where pipes divide requiring a certain fire resistance class, their passage must be sealed in a way that provides at least the same fire resistance as that of the barrier (wall or floor). Fire barriers play a key role in meeting the requirements of fire safety in buildings [4, 12], and therefore it is very important to properly seal the installations passing through them.

* Corresponding author. Tel.: +48-609-770-198; fax: +48-22-847-23-11. E-mail address: [email protected]

1877-7058 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of MBMST 2016

doi:10.1016/j.proeng.2017.02.113

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Bartłomiej Sędłak et al. / Procedia Engineering 172 (2017) 961 – 968

There are many methods and materials used to seal the penetrations, described in the literature [5-8, 10], and chose of the specific method generally depends on the kind of sealed installation. A good solution that provides adequate fire resistance for penetration seals, used mainly for sealing plastic pipes, is the use of fire-stop wraps and collars. Fire-stop collars are used on pipes in order to protect from heat leaks or fire penetration and are affixed to the location through which the installation passes. Fire-stop wraps are installed both on the pipe and inserted inside the penetration. Collars are usually mounted on both sides in the case of walls, or on the bottom in the case of floor slabs. Wraps are often mounted inside the wall in a manner similar to collars – in pairs on both sides of the wall or individually inside the penetration, or in the case of floor slabs – individually within the penetration, although there are some cases where they are mounted in pairs, as well. Figure 1 shows an example of the sealing of plastic pipe penetration in a wall using a fire-stop collar (a) and fire-stop wrap (b). a)

b)

Fig. 1. Example of the sealing of plastic pipe penetration in wall using a fire-stop collar (a); and fire stop wrap (b).

The main components of both, collars and wraps are layers of intumescent material. The number of layers, their length and thickness depend on the pipe diameter, pipe wall thickness and the expected fire resistance class. Collars and wraps work in a similar fashion in the event of a fire: under heat the intumescent material present within expands and squeezes the softening pipe, which then closes the area through which fire could enter an adjacent room. Figure 2 shows an exposed surface of plastic pipe penetration seals using fire-stop collars and wraps, after the fire resistance test has been performed. It is clearly visible that the intumescent material has closed the space formerly occupied by the pipe. The intumescent layers used in the collars and wraps are most often made of material based on expanding graphite. These materials begin to expand at about 140 0C and can increase their volume from a dozen up to several dozen times.

Fig. 2. The exposed surface of the plastic pipe penetration seals using fire-stop collars and wraps, after the test.


2. Fire resistance tests Fire resistance tests of penetration seals, according to European Union provisions should be carried out in accordance with the EN 1366-3 [3] standard. This standard defines the testing methodology for the penetration seals located both in floor slabs and in walls. The test on the floor slab is carried out to test the impact of fire from below the floor slab only, whereas the test performed for walls consists in heating on one side in the case of seals with a symmetrical cross-section option or on each side in the case of seals with non-symmetrical cross-section option. The tested elements are heated according to the standard time-temperature curve specified in the EN 1363-1 [2] standard, presented in figure 3.

Fig. 3. Temperature-time curves, A – standard curve, B – external fire curve [9].

It is important to identify appropriate test specimens for the testing in order to achieve the desired field of application. In the case of plastic pipe penetration seals using fire-stop collars or wraps, the scope of application depends on, among other elements, the pipe diameter, the pipe wall thickness and the pipe ending configuration (table 1), as well as the dimensions of the intumescent material used in the collars / wraps being put to test. Table 1. Possible pipe ending configuration. Pipe ending configuration Testing arrangement

Inside a furnace

Outside a furnace

U/U

Open

Open

C/U

Close

Open

U/C

Open

Close

C/C

Close

Close

The fire resistance test of penetration seals checks two performance criteria: fire integrity and fire insulation. Fire integrity is the ability of a structural element to withstand fire applied on one side only, without the fire being transferred to the unexposed side as a result of penetration by a flame or hot gases. During the test, fire integrity is verified using a cotton pad or gap gauges, or visually. The loss of integrity occurs when continuous fire that lasts more than 10 s appears on the unexposed surface of the test specimen or when the cotton pad ignites within 30 seconds of the moment of its application to the test specimen or if the gap created by the fire is large enough to be penetrable by a gap gauge with a thickness of 25 mm or alternatively 6 mm along 150 mm. Fire insulation is the ability of a structural element to withstand fire applied on one side only, without transferring the fire as a result of the significant heat transfer from the heated side to the unheated side. The maximum temperature rise on the unexposed surface of the test specimen is verified by means of surface thermocouples attached to the test specimen in the specific places.

963

964


Figure 4 shows an example of the distribution of thermocouples on the sealing of plastic pipe penetration through a wall using a fire-stop collar (a) and fire-stop wrap (b). a)

b)

Fig. 4. An example of the distribution of thermocouples on the unexposed surface of the plastic pipe penetration seal in the wall made using: (a) fire-stop collar; (b) fire-stop wrap.

3. Fire resistance classification Plastic pipe penetration seals in European Union are classified in accordance with the EN 13501-2 [1] standard, and the fire resistance class is given based on testing conducted in accordance with EN 1366-3 [3]. The classification takes into account the performance criteria presented in p. 2, which are assessed in the following manner: x fire integrity (E) – assessed on the basis of three aspects: ignition of the cotton pad, sustained flaming on the unexposed surface or gaps exceeding the permissible dimensions; the cotton pad inflammation criterion is not taken into account if the element is classified only for fire integrity without considering the fire insulation classification, x fire insulation (I) – assessed on the basis of maximum temperature rises on the unexposed surface of the test specimen limited to 180 0C above the initial temperature. Standard EN 13501-2 [1] for penetration seals defines the fire resistance classes shown in Table 2. Table 2. Fire resistance classes. [10] E

15

-

30

45

60

90

120

180

240

EI

15

20

30

45

60

90

120

180

240

In determining the fire resistance class for pipe penetration seals, one should also take into account the pipe ending configuration used in the test, thus, for example, the class of a pipe penetration seal should be written as EI 120 U/C. 4. A comparison of temperature rises on the unheated surface of penetration seals depending on method of their protection The comparison has been drawn up for 16 plastic pipe penetration seals in a reinforced concrete floor slab. The protected pipes were made of PE-HD (8 units) and PVC-U (8 units). The ending configuration for each of the pipe was the same – U/C. Each pipe was protected in two ways (with a collar or with a wrap). The collars and wraps sealing


the pipes of the same diameter and wall thickness use the same amount and the same type of intumescent material. The schedule of pipes tested in the penetration seals is shown in Table 3. Table 3. Pipes tested in the penetration seals. Pipe No.

Material

Diameter [mm]

Pipe wall thickness [mm]

Type of sealing

Layers of intumescent material

Symbols in the figures

1

PE-HD

200

11,9

Collar

8

PE-HD Collar Dmax Tmax (pipe/seal)

2

PE-HD

200

11,9

Wrap

8

PE-HD Wrap Dmax Tmax (pipe/seal)

3

PE-HD

200

7,7

Collar

8

PE-HD Collar Dmax Tmin (pipe/seal)

4

PE-HD

200

7,7

Wrap

8

PE-HD Wrap Dmax Tmin (pipe/seal)

5

PE-HD

32

3,0

Collar

3

PE-HD Collar Dmin Tmax (pipe/seal)

6

PE-HD

32

3,0

Wrap

3

PE-HD Wrap Dmin Tmax (pipe/seal)

7

PE-HD

32

2,0

Collar

3

PE-HD Collar Dmin Tmin (pipe/seal)

8

PE-HD

32

2,0

Wrap

3

PE-HD Wrap Dmin Tmin (pipe/seal)

9

PVC-U

200

7,7

Collar

8

PVC-U Collar Dmax Tmax (pipe/seal)

10

PVC-U

200

7,7

Wrap

8

PVC-U Wrap Dmax Tmax (pipe/seal)

11

PVC-U

200

3,9

Collar

8

PVC-U Collar Dmax Tmin (pipe/seal)

12

PVC-U

200

3,9

Wrap

8

PVC-U Wrap Dmax Tmin (pipe/seal)

13

PVC-U

32

2,4

Collar

3

PVC-U Collar Dmin Tmax (pipe/seal)

14

PVC-U

32

2,4

Wrap

3

PVC-U Wrap Dmin Tmax (pipe/seal)

15

PVC-U

32

1,8

Collar

3

PVC-U Collar Dmin Tmin (pipe/seal)

16

PVC-U

32

1,8

Wrap

3

PVC-U Wrap Dmin Tmin (pipe/seal)

The collars were attached to the underside of the floor slab, while the wraps were placed centrally within the floor slab. The cross-sections through the penetration seals for which the comparison has been prepared are presented on Fig. 5a and 5b. Moreover the figures show the locations of the temperature measurement on the unexposed surface, in the case of the penetration seals of installations with the minimum diameter. In the case of pipes with the maximum diameters, the number of thermocouples was doubled. a)

b)

Fig. 5. Cross-section through the tested penetration seals with location of thermocouples, pipes sealed with: (a) fire-stop collar; (b) fire-stop wrap.

965

966


Figures 6 and 7 shows the comparison of the average temperature rises for PE-HD and PVC-U pipes penetration seals, respectively for a: x x x x

pipe with the maximum diameter and maximum pipe wall thickness (Fig. 6a for PE-HD, and 7a for PVC-U), pipe with the maximum diameter and minimum pipe wall thickness (Fig. 6b for PE-HD and 7b for PVC-U), pipe with the minimum diameter and maximum pipe wall thickness (Fig. 6c for PE-HD and 7c for PVC-U), pipe with the minimum diameter and minimum pipe wall thickness (Fig. 6d for PE-HD and 7d for PVC-U). a)

b)

c)

d)

Fig. 6. A comparison of the temperature rises on the unexposed surface of the penetration seals of PE-HD pipes: (a) pipe with the maximum diameter and maximum pipe wall thickness; (b) pipe with the maximum diameter and minimum pipe wall thickness; (c) pipe with the minimum diameter and maximum pipe wall thickness; (d) pipe with the minimum diameter and minimum pipe wall thickness.

Figure 8 show the differences between the average temperature rise on the unexposed surface of floor penetration seals using a fire-stop collars, and the average temperature rise on the unexposed surface of floor penetration seals using a wrap, respectively for: x x x x

PE-HD pipes with the maximum diameter; with the maximum and minimum pipe wall thickness (Fig. 8a), PE-HD pipes with the minimum diameter; with the maximum and minimum pipe wall thickness (Fig. 8b), PVC-U pipes with the maximum diameter; the maximum and minimum pipe wall thickness (Fig. 8c), PVC-U pipes with the minimum diameter; the maximum and minimum pipe wall thickness (Fig. 8d). a)

b)


c)

d)

Fig. 7. A comparison of the temperature rises on the unexposed surface of the penetration seals of PVC-U pipes: (a) pipe with the maximum diameter and maximum pipe wall thickness; (b) pipe with the maximum diameter and minimum pipe wall thickness; (c) pipe with the minimum diameter and maximum pipe wall thickness; (d) pipe with the minimum diameter and minimum pipe wall thickness.

5. Conclusions Based on the results presented in figures 6 – 8, it is difficult to unequivocally determine which of the compared solutions is better. Both have reached the EI 120 U/C fire resistance class according to the criteria set out by EN 13501-2 [1] standard. Analyzing the graphs in fig. 6 – 8 it can be noted, that in the initial testing period, the temperature rise on the pipes protected with the wrap was much greater than the temperature rise on the pipes protected with the collar. This was because the intumescent material within the collar was directly subjected to high temperature from the very beginning of the test and thus reaches the temperature required to begin the expanding process faster as compared to the wrap, which was covered from the fire side by cement mortar. When the collar closed the pipe and thus slowed down the heat transmission process, the temperature of the intumescent material used in the wrap was too low to start the expansion process yet. In the later phase of the test, it was seen that the temperature rise value on the pipes protected with wraps began to decrease, which means that the intumescent material within the wrap has expanded and closed the pipe. In the final phase of the test, in most of the analysed cases the temperature rise on the pipes protected with the collar was much greater than in the case of the pipes protected with the wraps. This was because the intumescent material within the collar directly exposed to fire from the beginning of the test started to burn out, while the intumescent material of the wraps has not yet reached such a high temperature. a)

b)

967

968


c)

d)

Fig. 8. The difference between the average temperature rise on the unexposed surface of penetration seals using a fire-stop collar, and the average temperature rise on the unexposed surface of penetration seals using a wrap: (a) PE-HD pipes with the maximum diameter, with the maximum and minimum pipe wall thickness; (b) PE-HD pipes with the minimum diameter; with the maximum and minimum pipe wall thickness; (c) PVC-U pipes with the maximum diameter; the maximum and minimum pipe wall thickness; (d) PVC-U pipes with the minimum diameter; the maximum and minimum pipe wall thickness.

References [1] EN 13501-2:2007+A1:2009 Fire classification of construction products and building elements. Classification using data from fire resistance tests, excluding ventilation services. [2] EN 1363-1:2012 Fire resistance tests – Part 1: General requirements. [3] EN 1366-3:2009 Fire resistance tests for service installations. Penetration seals. [4] D. Izydorczyk, B. Sędłak, P. Sulik, Problematyka prawidłowego odbioru wybranych oddzieleń przeciwpożarowych, Materiały Budowlane 11 (2014) 62–64. [5] M. Kosiorek, Z. Laskowska, Bezpieczeństwo pożarowe, Cz.17: Przejścia instalacyjne, Materiały Budowlane 3 (2007) 83–88. [6] Z. Laskowska, Temperatura uszczelnień przejść rur metalowych przez ściany i stropy w badaniach odporności ogniowej, Prace Instytutu Techniki Budowlanej R.37(3) (2008) 19–32. [7] F. Orzeł, Rozwiązania techniczne przejść instalacyjnych z uwagi na bezpieczeństwo pożarowe, Elektro info 10 (2009) 42–45. [8] B. Sędłak, Porównanie skuteczności działania opasek i kołnierzy ogniochronnych z materiałami pęczniejącymi, Izolacje R.18(11-12) (2013) 63–68. [9] B. Sędłak, P. Sulik, Odporność ogniowa pionowych elementów przeszklonych, Szkło i Ceramika R.66(5) (2015) 8–10. [10] B. Sędłak, P. Sulik, Problematyka prawidłowego odbioru uszczelnień przejść instalacyjnych, Materiały Budowlane 7 (2015) 44–46. DOI: 10.15199/33.2015.07.10. [11] P. Sulik, D. Izydorczyk, B. Sędłak, Elementy decydujące o awariach wybranych oddzieleń przeciwpożarowych, XXVII Konferencja Naukowo-Techniczna Awarie Budowlane, 20-23.05, Szczecin – Międzyzdroje, 2015, pp. 771–778. [12] P. Sulik, B. Sędłak, Badania odporności ogniowej dużych mieszanych uszczelnień przejść instalacyjnych, Materiały Budowlane 7 (2014) 20– 22.