Bilge Petrol Vapour Detector

[spike2450]

Hi all
I've recently read about a bilge petrol vapour detector that auto switched the alarm and bilge blower. On searching all i can seem to find is Gas detectors, is this the same thing? Would a bilge alarm work near an inboard petrol engine etc. It seems to be an obvious thing to have. Any recomendations?
Thanks in advance.

 

[VicS]

I think you will find that the ordinary gas detectors will detect petrol vapour. They detect any flammable vapour for that matter.

The sensitivity of a given detctor will vary with different vapours so you would have to check the makers technical data to ensure that it operated in the correct range.

 

[Scarron]

Thanks, this prompted me to do the research as I need one as well.

Just spoken to Kevin Stockwell at http://www.nereusalarms.co.uk/html/products.html and they are now offering a version of their WG 1000/2000 LPG alarm specifically calibrated for petrol vapours. His advice was, that although people offer detectors that are claimed to do both it is better to calibrate the sensors to the target gas. Reference is PV 1000/2000. It also has 1 amp relay to run an external sounder which you could use to switch a heavier relay to drive your bilge blower. Sensors are waterproof too!

All sounds good to me so I think I'll go for one, I'll let you know how I get on.

I am also fitting a http://www.firetrace.co.uk/ System

With petrol I don't think the risks are as bad as some may make out. If properly engineered and maintained.

As far as safety goes however there is nothing wrong with a stout belt and a good pair of braces though!


Paul.

 

[ChasB]

"they are now offering a version of their WG 1000/2000 LPG alarm specifically calibrated for petrol vapours."

I couldn't find anything on their site. Do you have more info on that? And what kind of price are we talking about?

 

[Scarron]

No apparently it's a new development for them, he told me about it on the phone. pricing is the same as the LPG models but singe it require specific calibration he has quoted me a delivery of 7-10 days at the moment.

If you want any more info, give him a call, seemed very helpful on the phone.


Paul

 

[ChasB]

Hmm. I'd need two sensors, which makes it £240/£360 (two prices are offered, and it's not clear what the difference is due to). Not cheap.

I don't understand what there is to 'calibrate'. I would imagine the gas would somehow react with something in the sensor probe that is electrically measurable. Some gases would do that more than others and give higher or lower outputs, but how would you then differentiate that from reacting to the concentration of gas? Sorry to be so sceptical, but unless it's a sophisticated instrument I can only see it working or not working. Maybe someone else here can answer that. Or send him the link to the forum here - maybe he can answer that himself.

 

[jhr]

[ QUOTE ]
a bilge petrol vapour detector that auto switched the alarm and bilge blower

[/ QUOTE ] Yikes! Is this a good idea?

Picture this: Detector senses petrol fumes, switches on blower and alarm. The switch on the blower sparks whilst switching on. Ka-boom........ /forums/images/graemlins/shocked.gif

Petrol is perfectly safe so long as you regularly check everything, particularly fuel hoses/connections and the state of the petrol tank. Always run the blower before starting up, but not until you've lifted up the engine hatches to check for sight or smell of petrol.

Calor gas on a boat is far more dangerous, imho.

 

[ChasB]

The blowers on my boat are designed to not blow it to kingdom come. In fact there's a sign telling me to run them for 4 minutes before starting the engine. Likewise all bilge pumps etc are sealed.

but if anyone can advise me otherwise I would be very grateful...

 

[Anthony]

The key is 'ignition protected' any decent blower should be and marked accordingly, but if you are adding in a sensor and relay then be sure that the relay etc is also 'ignition protected'.

Anthony