cylinder cock design from latest live steam mag...

[Harlock]

We're looking at the design for cylinder cocks from the latest live steam magazine. (mar/apr 2009) It's a mechanically actuated slide valve of sorts that reveals a smaller diameter section of the valve to the steam flow to open.

We built a small test article. We found that even with a precise slip fit, they leak quite a bit out of the ends and out of the port when closed, having no proper seals.

This may not be an issue for a momentary blast of steam, what do you all think? I think that anything that potentially robs little bits of power here and there, especially on a tea kettle like our Chloe, is a bad thing.

My father is currently revising the design to incorporate O-rings and to be a rotary valve, if we can find O-rings that small.

Anyone have a better design?

Another option is a commercially available cock if anyone can recommend something they've been using reliably. Either steam or mechanical.

[gwerhart0800]

Unfortunately, don't have the information you are looking for, but I am interested in any results or discoveries. I have not found a US supplier for simple mechanical/manual cylinder draincocks. There is a suppler of steam operated ones:

http://www.livesteam.com/steam_accessor ... ercks.html

Reeves in the UK sells manual draincocks. They are listed under "Boiler Fitttings"/"Cylinder Draincocks & Lubricator tanks"

http://www.ajreeves.com/

Let us know if your "fix" to the recently published draincock works.

[alanstepney]

Almost all the cylinder drain cocks made (and used) over here, as sold by Reeves and others, and very basic, with a tapered plug, and no O rings or other seals.

They work, dont leak, and last for many years.
Equally as important, they are simple, to make and to maintain.

The only "secret", is to ensure that the taper of the plug is EXACTLY the same as that of the bore.
To do that, I set the lathe cross slide over by the correct amount, make the plug (s), and also, at the same setting, make a taper reamer (actually a tapered D bit) to open out the hole in the bore.

An old idea, but it seems to be the only way to ensure that both tapers are identical.
(I guess CNC would work as well, but trying to set to a standard reamer certainly doesnt!)

[Fred_V]

i made an English looking cock but made the bore straight. they will put out a wisp of steam, hardly noticeable.
Fred V

[JTolan]

Don't make them too bulky or shoot straight down or else they hit and blow up sand into running gear.

[bcody]

I used the steam activated ones on my Pacific and found them to be very satisfactory. The only problems were keeping the 1/8" OD steam lines intact. They tended to be very fragile. Bill

[prlawiii]

On the Allen Locos Yahoo group, Bill Shields has posted a design for a steam operated cylinder cock that seems quite simple and straightforward to build. It is what I intend to make for the Allen Mogul I am just starting. It is in the "files" section, under Bill Shield's drawings, and there are three detail drawings. It uses small o-rings for seals, so shouldn't leak at all.

Herman

Just got my Allen Mogul castings yesterday

[Harlock]

I am a member of that group and I took a look at the file. that is a nice little design, Bill, and the rings are along the lines of what's desirable for zero or close to zero leakage.

Alan: The design in the magazine has no tapers, that may be part of the problem.

[alanstepney]

Alan: The design in the magazine has no tapers, that may be part of the problem.

The taper is important as it allows some adjustment, and, as it wears, one can tighten the nut up part turn, to eliminate leaks.

No taper? Doesnt seem wise to me.

Personally, I dont like the idea of fitting O rings either.
To me, it adds needless complexity, and I like to keep things as simple as possible.
However, each to their own.

[gwrdriver]

>>JTolan opined . . Don't make them too bulky or shoot straight down or else they hit and blow up sand into running gear.

This is a sketch of the first drain cocks I ever made, for a LE American (many moons ago) and I had three concerns . . . that they not be too big, that they kind of looked like they belonged on an earlyAmerican rather than a Northern, and that they exhausted sideways and this is what I came up with. IIRC the bodies were turned from 3/8" brass hex.

[Bill Shields]

If you want drawings of the steam driven units that don't leak, let me know.

You don't need to sign up for the Allen Group to get them, I will provide here also.

Another variant, mechanical type use 'ramps and spring loaded balls. Been using these on my Hudson for almost 30 years with no problems.

Need drawings?

[pockets]

Bill,
I'd like to see the drawings for the ramp type. If you don't want to post, you have my email.

Thanks,
Greg B.