Application issues and pipe penetration seals

This is the third article in our series. In the first and the second part we covered topics like penetration seals of metal pipes, non-combustible pipe insulations (CS, CI, LS or LI arrangements), possible pipe end configurations (U/U, U/C, C/U, C/C), hanging and support distances of assemblies, pipes made of combustible materials, penetration seals of multi-layer composite pipes and combustible pipe insulations.

Now, it is time to look at some of the most important considerations, each construction company needs to take and which are not related to Promats products.

Installation of collars

As a general rule, in case of wall penetrations (except for shaft walls) a fire stopping collar, wrap or acrylic must be installed on both sides of the penetration. In case of floor penetrations, the mentioned products must be installed usually from the bottom side only, but there are exceptions the PROMASTOP®-W fire stopping wrap must be installed in a cross laminated timber (CLT) floor on both sides.

After careful examination of the data we obtained from tables in the previous articles, we might conclude that PROMASTOP®-FC fire stopping collars are installed on walls/floors (surface-mounted) or in walls/floors (built-in). Theoretically all collars with stable metal housing could be installed both by extending from the penetration plane (surface-mounted) and fitted into the penetration plane (built-in). Please note that the collar may only be used according to the classification in the test arrangement.

There are some interesting focus points to apply a fire collar correctly:

1. The annular gap between the plastic pipe and supporting structure must be sealed according to the tested configuration: for example backfiling with mineral wool of specific quality and annular gap sealing on both surfaces with PROMASEAL®-A. Application of the fire collar without annular gap sealing (hole between the pipe and the supporting structure) is allowed only if it was tested and classified that way.
2. The PROMASTOP®-FC fire stopping collar is classified for use on flexible walls, rigid walls and rigid floors.
3. The collar must be fixed for surface-mounted application with M6 or M8 threaded rods on flexible walls, while proper screwing is sufficient on rigid walls. PROMASTOP®-FC cannot be fixed on flexible walls with screws suitable for plasterboards (this applies to other products as well, and therefore the method of fixing the collar to the supporting structure during the fire test must always be checked). It is the same situation with soft batt penetrations: should the collar be classified for soft batt penetrations, it should be firmly fixed for example with threaded rods going through mineral wool boards or batts (it is difficult to imagine that any fixing which does not go through the structure is capable of fixing the collar in place during a test that might last for 90 minutes or longer). The PROMASTOP®-FC fire stopping collar is classified in 2 x 50 mm PROMASTOP®-CC soft penetration seal fixed with M6 / M8 threaded rods or min. 60 mm spiral screws or M4 spring toggle bolts and in recessed installation as well (the fixing latches are in between the two mineral wool boards).

Special applications of fire collars

Sometimes collars have to be applied in special situations, where the amount of intumescent inlay with an installation depth of 30 mm, (PROMASTOP®-FC3) is no longer sufficient. Promat therefore developed the larger PROMASTOP®-FC6 and PROMASTOP®-FC15 fire-stopping collars, suitable for installation depths of 60 mm and 150 mm. Special applications:

• pipe outer diameter larger than 160 mm
• shaft walls (the collar must be installed in shaft walls from outside, turned towards the wall, as it cannot be installed from the other side)
• angled (bevelled) penetrations
• pipe couplings

Soft penetration seals with PROMASTOP®-W fire-stopping wrap

Penetration seals without the use of fire stopping collars are very economical solution, as there’s no need for expensive collars with stainless steel housing, although they have their limitations. A fire stopping wrap can be used as built-in application only; combination with tested soft batt penetration only (wraps and soft penetrations aren’t variable). The PROMASTOP®-W wrap is classified in PROMASTOP®-CC and PROMASTOP®-I soft batt penetrations for walls and floors. The wrap can only be installed within the plane of the wall or floor; it might protrude up to 5 mm from the plane of the surface and it must not be applied with the coating, which forms part of the soft batt penetration (the coating would prevent the required foaming of the wrap by means of the cooling and thermal insulation effect). The wrap must be installed in such a way as to make its edge into the same flat plane of the batt’s lower plane with floor penetrations, and with wall penetrations it must be adjusted to the planes of both sides of the batt (considering the previously mentioned 5 mm protrusion).

The number of layers (depending on the material and the outer diameter of the pipe) must be considered (e.g. fire classification EI 120-U/C is ensured with two layers of PROMASTOP®-W wrap in 2 x 50 mm PROMASTOP®-CC soft penetration for PVC-U, PE-HD, ABS, SAN+PVC, PP-H and PP-R pipes up to 110 mm outer diameter).

Placing the mineral wool boards of the soft batt penetration into the flat plane of the penetration

There are different ways to install the required 2 x 50 mm thick mineral wool insulation into floors to achieve EI 90 classification:

• in the same level with the upper plane of the floor
• in the same level with the lower plane of the floor
• both of the mineral wool boards are in the same plane with the floor’s plane

The test arrangement of the chosen product must be taken into consideration. Promat’s soft batt penetration systems, PROMASTOP®-I or PROMASTOP®-CC, are classified for all three arrangements.

Distances between services within the penetration

The minimum distance between each service and the service’s distance from the building structure is defined in the most common soft batt penetration; it is not possible to install them more densely than the arrangement defined in the test. The following table includes some examples.

Total amount of services in the large penetration’s cross section

The whole cross section of assemblies (pipes including their insulations, cables including their support structures) within the large penetrations (soft batt, hard mortar, pillows, bricks) cannot exceed 60% of the penetration’s cross section.

This concludes our three-part article series on pipe penetration seals. The topic is wide and complex and requires a lot of knowledge and experience. Therefore, we kindly invite you to contact our technical team, by using the link below. We will be happy to answer any questions you might have regarding your projects. Let us design safer buildings together.

In one of our future topics we plan to focus on electric systems of the buildings, because cable installations are exposed to special risks and are worth some special attention. The planned final part of our fire-stopping series of articles describes penetration seals for cables, cable bundles and linear joints (gaps).