Gas supply valves linked to fire alarm system

[Wiz]

I've seen fire alarm controlled gas valve solenoids installed in various situations. Mainly in schools, mainly in kitchens, sometimes in laboratories and even often in boiler houses.

Does anyone know the regulations in respect of the necessity of installing such devices, and in which document(s) can these regulations/recommendations be found?

[Owen66]

If it's in schools, I suspect the guidance being followed originates in BB100 and BB101.

Regards

Owen66

[kurnal]

BB100 does not mention this. There are circumstances that justify shutdown for example in a gas fired crucible in a steel works,  or  in a kitchen if people are evacuating due to the fire alarm and may forget to shut off the cookers, or bunsen burners in a school lab.
I cannot think of any guidance that requires it as a matter of course. It is sometimes used as a backwards way to shut down the HAV systems in a fire - this is used for convenience since all the contol gear and switching is often connected back to the flame failure device. It may also be a compensating measure- for example in shopping centres gass mains should not be routed through malls, I guess if a shut off was provided this may be ok.
It would be interesting to hear other opinions on this, it does seem to be happening almost universally these days and can be a real nuisance due to the time it takes to start up equipment again afterwards.

[David Rooney]

I heard rumour from the kitchen fitters at one of our schools this is actually a requirement of the gas regulations....

[Wiz]

Thanks for replies guys.

I also look forward to anyone being able to confirm definitive requirements listed in authoritive documentation.

I wonder if this is another one of these 'we always do it, but we don't know why or who says we must' scenarios that crop up now and again!

[AnthonyB]

It seems to be one of those things that has fallen into common use regardless of the situation.

The hazard from high pressure natural gas feeding a fire is obviously high.

But how likely is it that the gas supply will become readily involved in a fire so as present a risk to life safety and escape such that a solenoid activated on any activation of the system anywhere in the building is required?

As Kurnal says there will be some circumstances where this is the case, but in the typical office building this is not necessarily the case. A local gas shut off to the main gas fed risk (the boilers) via a fusible link is normally always present and with this is a solenoid link to the main inlet always required?

In most normal situations a fusible link drop to boilers, plus a clearly signed main valve room & it's location marked in the evacuation pack plans should suffice - sometimes auxiliary shut-downs seem to go OTT

[Big_Fella]

I think it comes down to risk against the cost, and in this situation of shutting off the gas supply out weighs the cost.  On projects to provide an interface to shut the gas supply off will be around £100, so against the risk of the gas supply increasing the fire risk is justified.  In my opinion !

[Owen66]

I think it's mentioned in section 3.1.8 of BB100 - requirements to cut of the fuel supply? - that may be a slight misinterpretation of whats required if the fire alarm shuts down the gas valve rather than the emergency isolation stated, but its a justification I have heard from many sources

Regards

Owen66

[Wiz]

Owen66, my copy of BB100 doesn't have a section 3.1.8. Can you confirm what you are reffering to, please?

[Owen66]

Well I've just downloaded another copy from Teachernet and there is a section 3.1.8 which deals with boiler rooms (in the section entitled "Places of special fire hazard") - Page 39.

Generally it requires there to be (in new schools) a means of automatically shutting off the supply of fuel and also a means of emergency isolation. This should also serve to isolate the electrical supply to the plant. So a classic design solution would an EPO at the boiler room entrance and heat detection in the oplqnt space. These would then act (via an interface if required) to shut down the boiler panel safety circuit and cause total electrical isolation as well as de energising the gas solenoid.

Means of reset may be automatic subject to gas proving but the text also suggests that it is manual only if the incident is genuine

Regards

Owen66

[David Rooney]

Another copy of what

I did find this re kitchens.....

If gas supplies are fitted, refer to advice given in
the Institute of Gas Engineers 2004 publication
UP11 Gas installations for educational
establishments. Where gas cookers are provided
in classrooms (eg, for home
economics/domestic science lessons), the room
should be fitted with a lockable isolating valve
to enable gas supplies to cookers to be shut off
at the end of the day.

[Owen66]

Another copy of what

Building Bulletin 100

Regards

Owen

[Wiz]

Well I've just downloaded another copy from Teachernet and there is a section 3.1.8 which deals with boiler rooms (in the section entitled "Places of special fire hazard") - Page 39.

Generally it requires there to be (in new schools) a means of automatically shutting off the supply of fuel and also a means of emergency isolation. This should also serve to isolate the electrical supply to the plant. So a classic design solution would an EPO at the boiler room entrance and heat detection in the oplqnt space. These would then act (via an interface if required) to shut down the boiler panel safety circuit and cause total electrical isolation as well as de energising the gas solenoid.

Means of reset may be automatic subject to gas proving but the text also suggests that it is manual only if the incident is genuine

Regards

Owen66

Very interesting owen 66.

This is the link I am using to find BB100

http://www.dcsf.gov.uk/consultations/downloadableDocs/BB100%20July%2005%20-%20Complete.pdf

I wonder if it has been superseded? I notice the link address includes 20 July 2005.

Can you provide me with a link to the document that you have found?

[Owen66]

Here you go Wiz:

http://www.teachernet.gov.uk/docbank/index.cfm?id=12199

I think you may be looking at the draft for consultation - it did change in the final issue I believe

Regards

Owen

[Galeon]

And you should always get confirmation from the gas boys that their kit is flame failure , if you attempt to do this on an old system it tends to go bang.