Plastic Heating Pipes in common areas.

[Golden]

I've been assessing some  9-12 storey blocks where as part of a 'community energy saving solution' the RSL is fitting a community heating system consisting of a gas boiler on the roof with a pipework system of 2 x 100mm risers and various range pipes leading off into the individual flats; these pipes are all in the lobby area between the flats and the staircase. Having conducted a rudimentary test on these pipes it is found that they are thermoplastic and will burn and produce flaming droplets, burning is sustained after the heat source is removed from the sample.

The installers have put a scraping of intumescent around the pipes but clearly this isn't good enough. Has anybody else come across this situation and if so what fire stopping have you recommended - boxing in or pipe closures? Or am I simply going OTT?

[lancsfirepro]

You'd normally use intumescent surface mounted pipe collars for that application.  Clip them round the pipe and fasten them to the ceiling.  Worrying that they're not already doing this though.

[nearlythere]

I've been assessing some  9-12 storey blocks where as part of a 'community energy saving solution' the RSL is fitting a community heating system consisting of a gas boiler on the roof with a pipework system of 2 x 100mm risers and various range pipes leading off into the individual flats; these pipes are all in the lobby area between the flats and the staircase. Having conducted a rudimentary test on these pipes it is found that they are thermoplastic and will burn and produce flaming droplets, burning is sustained after the heat source is removed from the sample.

The installers have put a scraping of intumescent around the pipes but clearly this isn't good enough. Has anybody else come across this situation and if so what fire stopping have you recommended - boxing in or pipe closures? Or am I simply going OTT?

Not OTT if destruction of pipe work can cause breech of compartmentation. Boxing in or Int collar, both properly done, is a solution.

[Midland Retty]

You are certainly not being over the top at all. It is critical that the level of compartmentation is maintained in high rise blocks.

[kurnal]

Thats not pink expanding foam I can see in the pic? Dear oh dear.

[Golden]

Thanks for the responses guys - I wanted to double check as the RSL has a problem that could cost some serious money!

I think the pipe collars are the answer for the main breaches but they will have to be secured to the adjoining surfaces so it will be expensive as there are at least six block where this is happening and that concrete slab is not easy to drill! The pipes entering the flats aren't so much of a worry regarding the penetration as these go down to 20mm diameter and below but will need some fire stopping plus the flammability aspect is of concern and is under further investigation.

And yes that is a little bit of pink foam you can see!!

[lancsfirepro]

On the plus side.... Should the pipe get burnt through, the water inside will act like a sprinkler system. 

[nearlythere]

On the plus side.... Should the pipe get burnt through, the water inside will act like a sprinkler system.  

Does your ADB not permit pipework of low diameter penetrating compartments just to be smoke stopped? Something in the back of my brain...... Check it out.

[SamFIRT]

If there is water in the pipe it won't burn through at all. The water will absorb the heat and prevent it. Have you never seen the experiment with water being heated in paper cup or a balloon filled with water having a Bunsen flame played over it?

http://www.youtube.com/watch?v=5Y_L5n0CeiY

http://www.youtube.com/watch?v=HK6G4-DaFv0

[Golden]

Hi Sam, my colleague and I did discuss this aspect of the heating pipes and it is one of the reasons I posted here to gather opinion. There is a worry that the heat of a fire may be enough to turn water to steam in a small section of the pipe and cause it to break? We are also assuming that there is water in the system at all times.

Do others consider that this may permit the pipes to remain unprotected?

[jokar]

Interesting.  I understand the compartmentation issues and the need for ensuring that smoke and fire spread can not happen.  However, where is the heat source which will damage the pipe runs to such an extent that you will get heat and smoke travel?

[lancsfirepro]

Does your ADB not permit pipework of low diameter penetrating compartments just to be smoke stopped? Something in the back of my brain...... Check it out.

It does but it requires the pipe to be a snug fit in the hole - the image shown looks like the proverbial p**ck in a welly. 

[Midland Retty]

Interesting.  I understand the compartmentation issues and the need for ensuring that smoke and fire spread can not happen.  However, where is the heat source which will damage the pipe runs to such an extent that you will get heat and smoke travel?

Its more to do with the risk of fire in a flat for example spreading into service ducts / risers rather than the other way round.

I don't subscribe to the idea that water in pipe will mean it won't burn. I've seen those experiments that SAM refers to, but theres a difference between controlled experiments to real life conditions, and it all depends on numerous factors. 

[Golden]

Jokar - it works both ways for me - mainly the fire spreading from the flat into the common areas and then spreading through the common areas, secondly a fire in the common areas from combustibles that shouldn't be there (mattress/TV/Fridge all found in the common areas at the time of inspection) into the flats.

With respect to the water in the pipes and making them non-combustible in theory at least I am trying to get some clarification elsewhere but appreciate all of the contributions.

[Goodsparks]

The pipe looks more like Mapress plastic coated steel, rather than PE or PVC. It's unusual to see crimped steel fittings on plastic tube of that size, usually glued or fusion welded.