The industry is moving away from compounds to other systems to protect metal, plastic and fiberglass composite pipes when passing through fire rated or watertight divisions. Here is why.
1. Long and heavy sleeves
Compound solutions require a sleeve to hold various materials including numerous forms of filler material, intumescent rubber and of course, two layers of compound. The length of the sleeve typically depends on the diameter of the pipe and the material needed for the fire rating required. The solutions often require compound on both sides of the structure in addition to the filler material resulting in typical sleeve lengths of between 180 and 250mm long.
Long sleeves reduce the ability to add a joint or coupling to a pipe passing through the penetration close to the structure, or when trying to route the pipe system in a different direction. The shorter the penetration sleeve, the more flexibility exists when routing a pipe system within a confined space.
Longer steel sleeves also add weight. When extrapolating over multiple penetrations, the potential savings with lighter solutions becomes significant. Weight savings are important to support greater speeds, improved fuel efficiencies and a reduction in the environmental footprint.
2. Extensive installation time
Compound solutions have multiple time-consuming steps within their installation processes:
- Welding of the sleeve on both sides of the deck or bulkhead.
- Cleaning of all surfaces including the inside of the sleeve and the outside of the pipe.
- Insertion of filler material where packing must fill the void inside the sleeve.
- Application of the correct depth of compound to both sides of the deck or bulkhead.
- Smoothing and compacting around the pipe to get a seal with no gaps or cracking.
- The curing time can range anywhere between 24 hours and 30 days. During this time, any movement of the pipe could cause an issue with the sealing properties and the overall performance of the sealing solution.
- Some compound solutions require a third party installation company to finalize the process. This can lead to delays caused by logistical and planning difficulties.
3. No reinstallation flexibility
Over the service period of a vessel or platform, numerous pipe repairs might take place. If a corroded steel pipe system is to be replaced, access is required to both sides of the deck or bulkhead in order to cut away the compound and access to both sides is not always an easy task.
Once the compound, filler material and corroded pipe are removed and the new pipe is in place, new compound must make a clean joint with the sleeve edges or any remaining compound. This process needs to be repeated on the other side of the structure and then left to cure. Due to a limited shelf life of most compound solutions, access to new compound might not be easy if the vessel is still in service.
Allowing the compound to cure and form an initial seal can take many days. If any gaps and cracks appear during the curing period, levels of fire rating, watertight or gas-tight performance could be compromised.
