Plumbing Cylinder Drain/Vent Petcocks together

A special section just for steam engines and boilers, as without these you may as well fit a sail.
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JonRiley56
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Plumbing Cylinder Drain/Vent Petcocks together

Post by JonRiley56 »

Hello All,

I have a petcock at the top and bottom of the cylinder for draining/venting and heating through. I have two concerns. Firstly, they become hard to turn when the engine is hot, and secondly, they are not plumbed down into the bilge so that when they are open I dump an impressive display of steam/water vapor/hotwater all over the floor of the boat.

Would it be OK for me to replace the petcocks with more typical valves and pipe them into a common "vent" that extends down into the bilge ? I cant see why it would be an issue but though I should seek counsel prior to trying it.

as always, any thoughts would be appreciated.

jon
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barts
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by barts »

I've always done this w/ my boat w/o issues; in fact, now I just plumb them together and then into the exhaust to further minimize the mess.

I use 1/4" ball valves for this purpose; they work very well and are no trouble to turn. If a more 'olde timey' appearance is desired, a wrapping of 1/8" sash cord and wood covers for the handles will do wonders.

- Bart
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Bart Smaalders http://smaalders.net/barts Lopez Island, WA
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TahoeSteam
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by TahoeSteam »

On my fathers boat as well as mine, we have our drains plumbed into the exhaust. My father has nicely made individual cocks on his, where as on mine there is a single valve at the bottom of each cylinder, that when opened communicates with the upper drain as well as the exhaust.

On a side note, the gentleman who built my boat also plumbed the packing glands to the exhaust. If there is a leak in the packing it doesn't spray everywhere. The only way to tell there's a leak is a little weep hole built into the gland follower.
JonRiley56
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by JonRiley56 »

That is a great idea !!! I will see if I can do that with mine.

thanks !

jon
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Rainer
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by Rainer »

JonRiley56 wrote: pipe them into a common "vent" that extends down into the bilge
If the translation of common vent would be "only one valve" for all than the answer would be no. But vent seems not to be the short form of the German "Ventil" = "valve" - so vent in english is just a common pipe - OK I see - this was only a fast readers problem by a non english speaker like me.

With seperate lines to the bilge you get a better overview which cylinder is still condesing at which side. For this the old steamboats have short lines from the valves which reach into an "open" funnel which than collects all the water to the bilge. So the engineer can watch what is comming from where...

If you got some routine with your boiler and engine you can pipe them together behind the valves and close them individually by estimated time. I do it in the order HP top - HP bottom - LP top - LP bottom - LP valve chest.

My bilge water is running into the ash pan and evaporates there - so no trouble with this. And if you don't cross the ocean you have no trouble with feed water loss.

If you connect to the exhaust/vacuum you will never ever have issues with leaking valve - but maybe with the vacuum ;-)
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by Mike Rometer »

Rainer, a 'vent' in English is simply an 'opening or outlet', allowing an escape (of air/steam/etc.). I do see the correlation with your Ventil though.

I apologise for our language it can be too diverse at times. It is really not a single language at all of course, just bits of everybody else's stuck together. :lol:
Retirement is about doing what floats your boat!

A BODGE : - A Bit Of Damn Good Engineering.
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Re: Plumbing Cylinder Drain/Vent Petcocks together

Post by fredrosse »

I have always used little brass "bar stock" valves for cylinder condensate venting. These are most commonly found on the connection for water supply to refrigerator ice making machines, and they are available with 1/8 inch pipe thread connection inlet, and 1/4 inch outlet compression fitting for 1/4 inch outside diameter copper tubing.

My 3-1/4 inch bore x 5-1/4 inch stroke engine clears very well with these small valves. They have never become troublesome as the cocks with a tapered 1/4 turn plug which, as mentioned previously, tend to sieze up when heated.
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