Spirax Valve

[snupple2011]

I have some of the (well all) Armstrong Powerhouse packs and some have a 'ticking Spirax" and I am interested in what this valve is controlling when the engine is stationary?


(I did google a bit but only found out its a valve)

[Wikkus]

I'm not an engineer and this is not therefore a technical post, but my understanding was that the "Spirax valve" is part of the compressed air dryer that removes moisture/condensate from the compressed air system, and that the noise is the sound of it venting to atmosphere. I'd imagine it requires electrical current to operate.

Rgds, Rik.

[bigphill2]

Hi Snupple
A quick google shows this to be a valve made by the "Spirax-Sarco" Company here in OZ. They make a wide range of valves and maybe this one is just to make an irritating noise for our UK friends

Regards....Phill

[snupple2011]

Hi Snupple
A quick google shows this to be a valve made by the "Spirax-Sarco" Company here in OZ. They make a wide range of valves and maybe this one is just to make an irritating noise for our UK friends

Haha Cheeky, thats actually as much info as I found as well. but Rik's info is interesting - thanks

[veetkam]

I'm not an engineer and this is not therefore a technical post, but my understanding was that the "Spirax valve" is part of the compressed air dryer that removes moisture/condensate from the compressed air system, and that the noise is the sound of it venting to atmosphere. I'd imagine it requires electrical current to operate.

Rgds, Rik.

The fart value doesn't need electric to operate, it's as you stated a value that allows mositure to be expelled from the air system

[snupple2011]

Hi Snupple
A quick google shows this to be a valve made by the "Spirax-Sarco" Company here in OZ. They make a wide range of valves and maybe this one is just to make an irritating noise for our UK friends

Ha, cheeky!

Thanks guys, very interesting!

[mbtech22]

I have some of the (well all) Armstrong Powerhouse packs and some have a 'ticking Spirax" and I am interested in what this valve is controlling when the engine is stationary?


(I did google a bit but only found out its a valve)

The valve to which you refer is fitted to a number of locos Class 47 etc. and its purpose is to drain condensate from the air reservoirs. It does not require any electricity to operate and works on air pressure differential. When the valve closes it allows a small quantity of air and any water into a chamber and traps it as the valve shuts. When the pressure in the air reservoir drops a predetermined amount (say about 5psi) the valve will open (giving its distinct noise) discharging a small amount of air and any water it has collected. This cycle repeats at the air pressure rises in the reservoir from the operation of the compressor and falls due to the operation of the brakes.
Similar valves are fitted on steam heated carriages to remove condensate from the steam heating pipework. These are of a slightly different design and don't make the same noise. They are however still called Spirax Valves, presumably due to the manufacturer.

Mark Brinton