Cylinder drain cock ideas??

[Mcgyver]

I've have to make a bunch of cylinder drain cocks and am looking for ideas.  I'll probably set up a turret to make a big batch (stationary and marine envisioned) so something that would look right on many different engines would be ideal.  The current need is for a Stuart triple expansion engine.

I'm familiar with the typical Stuart bit, and Stew did a great job in this thread of describing their manufacture :  http://www.modelenginemaker.com/index.php?topic=395.0

I may go that route, but I've never been enamored with the taper style valve and having it stick straight out doesn't do much for me.  I don't have much exposure to full size ones, but have the spray go all over the engine and operator doesn't seem very prototypical.

There's the 90 degree needle value style like this:  https://modelengineeringwebsite.com/Triple_expansion_engine.html

But it lacks the pizzaz of the globe type.  It also looks awkward to get at underneath the piping

There's the auto type but I'm not sure how they work with air.

Anyone have a different idea?  Any prototype examples? 

Help me decide what to make!  thanks!

So...

[tghs]

getting ready to make a set,, been looking at the 90 degree type also,, my needs are for something that will look scale and less flamboyant,, thinking of making a wrench/tool to work them, a tube with slot on one end and a knob handle on the other end..

[Jasonb]

It's quite common to plumb them in as was done on full size, the Stuarts can have a small copper pipe soldered into the end or you can get or make ones with threaded ends to take a nut and nipple type connection.

Couple I have made in the past





Those last two are linked together and can be operated vial linkages from th edriving position



Plumbed Stuart ones

[Mcgyver]

Thanks for the ideas.  Jason, what was the process for making the curved spout?  i could see investment casting those, but wouldn't want to whittle 1/2 a dozen of them!

I like the idea of the wrench tool.  90 degree needle valve with a small tube carrying the fluid away might be the way to go

Anyone have any sight or prototype examples?  I suppose it depend on the size engine - you'd think that would factor into what type and where the valve would be.

 

[Chipswitheverything]

Hi, I did a write up a while ago about making the usual Stuart type drain cocks for the Triple and similar, made a dozen of them.  Though perhaps not what you are proposing to do, article is in Engine Ancillaries on this forum, starting July 05 2016     Dave

[steamer]

Having a flow through or "cross" style drain valve for the lower cylinder drain on a marine plant really neatens the layout out.
75 HP 7x 14 x 12 compound.   

[steamer]

I made a set of "Cross" drain valves for my launch by modifying some PM Research right angle valves.  I did this by brazing on a coupling union on the opposite side.   That way it's always open to the upper valve but closed to the side.     Reduces your drain lines by half.

Dave

[Jasonb]

I'm afraid there was a lot of whittling to making those draincocks with the bent ouitlet. Started with 5/8" square stock and used a form tool to shape the body. milled the rough spout shape then filed the res and soldered on the threaded part.

[steamer]

From my engine...

1.5 3.0 x 2.5 compound     1/16 NPT ports in the cylinder block.    5/16" drain lines  ( 8mm)

[steamer]

If you add a drain cock to the cylinders, consider other places where water will collect.   On my engine, it was the bottom of the receiver pipes as well.

Dave

[derekwarner]

"I made a set of "Cross" drain valves for my launch by modifying some PM Research right angle valves"

Dave ......do you mean you made'converted 'I' style valves to 'L' ported valves?...which give the option ...

1. top of piston port to drain
2. bottom of piston port to drain
3. both ports isolated

Derek

[Mcgyver]

Jason...thanks for all the photos, they do look good.   That's the sort of thing an SLA printer and investment casting would be great for!

From my engine...

i like those - did you make them?

[steamer]

Jason...thanks for all the photos, they do look good.   That's the sort of thing an SLA printer and investment casting would be great for!

From my engine...

i like those - did you make them?

Yes....and we still call it a cross.

[john mills]

when fitting drain cocks th bottom of the vale chest is good as it helps while heating up getting ready to start
several of the full-size engines have them. It is hard to tell what was original because by the time they end up in the museum they are missing.
     John

[steamer]

My receiver has a drain cock at both the HP and LP low.points    and its really necessary.