Cylinder drain management?

[DetroiTug]

Ran the engine for the first time last night and had to go through the warming through sequence. What it currently has is six individual drains, that spit quite a bit of water on start up. I'd rather not have that in the engine space. Is it possible to just run six individual lines into a manifold and then exhaust it out a thru hull fitting with one valve? These will more than likely fill with water as they condense steam and not cause any difference in engine displacement during normal operation??

-Ron

[steamboatjack]

Ron,

No no if you do this the steam will pass from one end of the cylinder to the other! It can be done but you need to fit a small non return check valve of some sort on each line preferably at the cylinder connection. A small ball and very light spring would suffice, could be made up from a connector fitting. the space between the checks and the shut off valve would then soon fill with condensate and lock the system.

The usual system in the UK is to run the drains into the ashpan which is kept wet, the drains help keep the water level in the ashpan which is beneficial to steaming anyway (don't ask me why).

best regards
and well done with a great boat.
Jack

[DetroiTug]

Jack,

That sounds like a great idea. I need to do something with it, there is a lot of condensate that sprays against the side of the boat. It still laying in the bilge incidentally, that weld doesn't leak anyway

Thanks, Ron

[farmerden]

Why don't you plumb it back to the hotwell? Every drop you save gives you more steaming time before you run out! Den

[steamboatjack]

Its not a good idea to run dirty drains into the hotwell, cylinder oil and other contaminants need to be kept out of the feed water.
Jack

[DetroiTug]

This is exhausting up the stack, no plans to condense. This will be ran in freshwater all the time.

-Ron

[artemis]

Ran the engine for the first time last night and had to go through the warming through sequence. What it currently has is six individual drains, that spit quite a bit of water on start up. I'd rather not have that in the engine space. Is it possible to just run six individual lines into a manifold and then exhaust it out a thru hull fitting with one valve? These will more than likely fill with water as they condense steam and not cause any difference in engine displacement during normal operation??

-Ron

The biggest problem I have heard,seen,done with valve chest/cylinder drain cocks is remembering to shut them off when the line is no longer producing condensate. And this would particularly be the case with feeding them into a common manifold as you can't see the discharge, and one could get "crossover". "Automatic" Cylinder drain valves are made for this purpose for "Garden" (scale) locomotives. Each is nothing more than a SMALL single acting piston/cylinder. The small piston is connected by a short rod to a poppet valve and the valve connected directly to the cylinder drain hole. Since the purpose of the valve is to prevent condensate from being trapped between the piston and cylinder head, the boiler pressure on the small piston serves as to keep the valve closed until the pressure on the valve from the condensate compressed against the cylinder head (a "slug of water") forces the poppet valve off its seat. Since boiler pressure keeps it seated, the valve will not be opened by the pressure of the steam in the cylinder. Many garden railroaders use them claiming less problems with bent piston rods, blown cylinder heads, etc. As they close when there is no longer condensate present there is no chance of "live" steam from another cylinder/other end of the cylinder crossing over. And they only exhaust when there is condensate to remove. The valve chest is another matter, but certainly not as important as the cylinder drains and could be handled manually. This also prevents those bent rods, etc. that occur when "pausing briefly" at a lock, etc. and forgetting to open the drain valves when starting up again. Soon as I find a couple of suppliers I'll edit this to supply website info.
Superscale at http://www.superscale.biz carries a cylinder drain. Select the "Download Complete Catalog" button from their home page, then Speciality Valves > Cylinder Cock. Although $ 71 US, once you buy one you should be able to make additional for yourself. Looks like a simple lath project.

[dhic001]

I personally like to have an individual valve on each drain point, with all of them leading to a common manifold which drains overboard via a skin fitting (above the waterline). Sure there might be a little crossover, but it doesn't matter for the short time the drains are open. Individual valves mean you can control which bits are draining as you go through the warm up process, or during manoevering, but the drain to overboard means you don't end up with a mess in the bilge. If one valve is left on, or is leaking, its obvious by the steam exiting the skin fitting, or the noise if its only leaking.

I personally like to see everything waste go overboard, the bilge should be kept as dry and clean as possible, and believe me, its easier to keep it clean if its dry. As a result, its only the excess oil fron the engine that ends up in the bilge on Zeltic, everything else goes overboard (if waste material) or back to the hotwell if its condensate or just boiler steam (from the kettle).

Daniel

[DetroiTug]

Thanks for all the input on this, the info you guys provide is really appreciated. I'll go with six individual check valves manifolded to one valve and vent it out the side, above the water. That way, a quick peek from the helm will let me know that it's closed.

-Ron

[Dhutch]

It was before my time, but our engine originally had the three drains (one valve per cylinder and one for the slide valve on the LP) connected together and plumbed away but it was felt that it was more suitable to have venting locally so that you could monitor what was being ejected and if it where steam or condensate. They simply running to the bilge and are lifted out with everything else.
Perhaps less of an issue if you know the engine and are a single user, but we have a large number of secondary crew and although ive not tried it any other way i think being able to see whats going on helps with the training process.


Daniel