GRP Firewater Pipe System? 4

[Donkin]

I have taken over for a large civil project and my predecessor specified GRP/ Epoxy for the seawater firefighting system.

This was to be a wet system and GRP was accepted. The system is now to be a "dry" system with the pumps only running after operator initiation.

Does GRP/ Epoxy have a two hour fire rating if it is a dry system?

All help appreciated, thanks in advance

 

[corrosionman]

GRP can be made with flame retardent resin but this will not have a two hour rating (even if it was specified which is extreemly unlikely). GRP can be overcoated with an intumescent coating to give 30 minutes I believe. I suggest you get the Spec of what was used initially and if necessary I,ll look up a supplier of Intumescent paint for you. Cheers David W

 

[gvanbeek]

Donkin:

Are there any regulations that need to be met (e.g. IMO, coast guard, etc.), or is this a self imposed requirement?

In addition to the intumescent, you can go to a chartek coating, but the cost and weight will roughly double.

There are FRP systems (e.g. Fiberbond.com) which have been designed to 5 minutes dry 25 minutes of flowing water without passive fire protection (chartek, intumescent), but 2 hours dry without flowing water will most likely not be fesible.

 

[Donkin]

The two hours is a Client imposed requirement. The Client wants Cu/Ni piping but our Lead Piping Engineer has specified GRP.

 

[gvanbeek]

When I posted I was assuming this was for the deluge portion of the firewater system. After rereading your post, I realized that the system was originally designed to be loaded. What was the reason for going to a dry system? There is nothing like having an emergency situation, and having to hit the "start" button next to a hose reel and wait for the entire system to charge before getting water to your hose!

The best firewater systems that I have seen are loaded and maintained with an electric jockey pump. If the pressure drops below a setpoint (as in someone opens the hose), then the diesel powered firewater pumps automatically startup. It takes one crucical step out of a critical situation.

The US coast guard which regulates floating Oil platforms (TLP, Spar, etc.) have accepted FRP loaded firewater systems that meat IMO Level III firetesting. For the deluge portion, it must meet a 5 minute dry 25 minute flowing water.

The Navy Tested Cu/Ni piping in a dry then wet deluge piping and had a catastrophic failure when the water flashed to steam when it was introduced to the cherry red hot pipe. It believe it was partially based on this that the coast guard moved to accept FRP in dry/wet situations.

Has the customer proposed a test protocol. In some cases only a section of pipe is tested. A problem that I have seen in the past is the jointed conections in a fire test. The gasket selected, may not be able to handle the test.

What is the regulatory body that governs the location of this platform?

 

[jabpiping]

IN ACCORDANCE WITH IMO A753(18)LEVEL 3 FIRE ENDURANCE, WHERE THE PIPING SYSTEM IS INITIALY DRY AND THEM FILLED WITH FLOWING WATER WITHIM FIVE MINUTES OF EXPOSURE TO FIRE.

 

[haripals]

GRP manufacturer / supplier can be consulted if the pipe listed to withstand a two hour fire rating or not in a dry system. Because GRP/FRP pipework properties varies from manufacturer to manufacturer. or the supplier can be requested for suitable treatment to supplied piping to meet projct requirements.

Thanks

 

[SJones]

We had a similar problem offshore Iran where the contractor purchased GRP for a supposedly 'wet' system that turned out to be dry. The supplier, Ameron, clearly stated that the product supplied is not for dry service. That resulted in the need to qualify a passive fire proofing material applied to the GRP to cover for exposure to fire when dry. Our scenario was dry 3 minutes before activation and was resolved using 1200 microns Carboline Ocean Coating 477. If the GRP supplier does not have a qualified PFP/GRP combination as per UKOOA or ISO 14692 (most unlikely for 2 hours dry) then you will be looking at having to qualify them as per those standards (a pretty tall order at 2 hours dry).

Steve Jones
Petroleum Development Oman LLC
Muscat
Sultanate Of Oman

 

[stanier]

As an aside to this discussion, what are the waterhammer consequences of running a dry/wet system? I would think that the liquid column would advance quickly through the dry system. Then as the system approaches full the water column would be arrested. Hence a surge event would occur.