CABLE & PIPE PROTECTION Intumescent material halts spread of fire through penetrations

(Left) In the face of a fire, the intumescent material in Fireseal's Pipelock PL transit expands to squeeze the plastic pipe shut.

(Right)Fireseal's Squeezer CTT cable transit contains an intumescent material which swells in the heat generated by a fire to form an impenetrable barrier.

A new solution for ensuring the integrity of cable and pipe penetrations in the face of fire has been introduced by Fireseal Engineering.

For cables the product is known as the Squeezer CTT, and consists of one or more steel tubes which pass through a fixing plate that is welded or bolted onto the barrier to be penetrated.

The tubes are internally coated with a thin layer - just 1mm - of an intumescent material which when exposed to the heat of a fire swells to 30-50 times its original size, blocking any possibility of the fire passing through the penetration.

A second product, Pipelock PL, is available in sizes up to 200mm for plastic pipe penetrations, such as those in living quarter toilets. This consists of a canister in two halves which is bolted on either side of the barrier. The inside of the canister sections is coated with the intumescent material.

"As it swells, the intumescent material creates a pressure of up to 8 bar, thus squeezing the pipe shut," says managing director Bo Ohlsson. With both products, a silicon sealant must also be applied at one end of the penetration to prevent the passage of cold smoke.

The products have been approved by most relevant certifying authorities, including DnV and Lloyd's Register, for A60 ratings for offshore and marine applications.

Although marketing of the new products to offshore clients is only in the initial stages, an order for Pipelock PL units has already been won for Elf's N'Kossa development in West Africa.

The offshore sector is a major market for Fireseal's products, Ohlsson says. The Studsvik FS-03 line of penetration seals, which uses silicon foam as the sealing agent, is to be found on many offshore facilities.

Among the latest entries on the company's reference list is Canada's Hibernia development. In addition to the conventional cable and pipe seals, Fireseal's products are specified for the perimeter seals for the utility shaft of the platform's concrete gravity base. These will be placed between each deck and the shaft wall, which has a circumference of 17 metres.

Delivery of the perimeter seals gets under way in August. The Hibernia sale was won by Fireseal Canada, a joint venture set up with a company based in St. John's, Newfoundland. Seal manufacture will take place in Sweden and Canada.

Fireseal products have also recently been supplied to the Sleipner West and Troll Gas projects in Norway, the Brent redevelopment in the UK, and the Goodwin project in Australia.

Ohlsson welcomes the trend which has seen the company become involved in the engineering of the penetrations. "We are very interested in increasing our cooperation with the project engineering companies at an early stage," he says.

"We are now doing this with Technip for the N'Kossa project. We're on a learning curve because this is the first major project in which we've been involved in the early engineering as well as product supply. But we've discussed becoming involved at this stage with leading engineering companies such as Aker and Kvaerner and to some extent played a part in the engineering on the Sleipner West project."

Ohlsson is keen to stress the efficiency of Fireseal products in blocking the passage of toxic smoke and fumes - this is what has proved the killer in recent offshore and marine disasters, he says.

He would like to see the safety standards practiced in Norway taken on in other countries. "The worst competitor we have is ignorance," he says. "If you go for some cheap, low-technology product, it won't do the job. It's no good making penetrations the weakest link in the chain of defense against fire."

For more information contact Bo Ohlsson, Fireseal Engineering AB: telephone 46 155 26 80 40 or fax 46 155 28 41 10.

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