Mounting Water Glass

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, cbrew

jlakes85
Posts: 135
Joined: Thu Feb 23, 2012 6:07 am

Mounting Water Glass

Postby jlakes85 » Fri Nov 17, 2017 8:29 am

Hi all,

I think I know what needs to be done, but I'm assuming that the glass will need to be cut to length, unless it can be mounted on an angle, for which I don't think I will have the required real estate. The gauge I'm looking at has both a valve and shutoff cock on the bottom to allow for blowing down properly. I would just need to add a valve on top to complete the setup. Any input is greatly appreciated as always

-jlakes85

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 9:17 am

The water glass should be mounted so that the lowest reading is a minimum of 1/2" over the top of the crown sheet. On my own locomotives I make the lowest reading 1/2" over the front of the crown sheet on a 5" grade. The top fitting should enter the shell within 1" or so from the top. The bottom fitting should project into the water space about halfway into the water space.

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 9:38 am

Marty_Knox wrote:The water glass should be mounted so that the lowest reading is a minimum of 1/2" over the top of the crown sheet. On my own locomotives I make the lowest reading 1/2" over the front of the crown sheet on a 5" grade. The top fitting should enter the shell within 1" or so from the top. The bottom fitting should project into the water space about halfway into the water space.

Here is a copy of a page from the Baldwin Steam Locomotive Standards.[attachment=0]Water Glass and Column.
Attachments
Water Glass and Column.pdf
(47.18 KiB) Downloaded 110 times

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 9:40 am

Marty_Knox wrote:The water glass should be mounted so that the lowest reading is a minimum of 1/2" over the top of the crown sheet. On my own locomotives I make the lowest reading 1/2" over the front of the crown sheet on a 5" grade. The top fitting should enter the shell within 1" or so from the top. The bottom fitting should project into the water space about halfway into the water space.

And here is the ALCO page on locating the water glass
Attachments
boiler on grade.pdf
(132.85 KiB) Downloaded 82 times

trivettj
Posts: 55
Joined: Mon Sep 03, 2012 10:01 pm
Location: banner elk north carolina

Re: Mounting Water Glass

Postby trivettj » Fri Nov 17, 2017 11:35 am

Marty is 3/4" above the top of the crown sheet safe for the bottom of the glass ? Would that be about the same as 1/2" above on a 5 percent grade?

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 11:55 am

How long is your firebox? Finding the height is an exercise in simple geometry.
On my Green Goddess, a modified RGS 20, it is 1 5/16" above the rear of the crown sheet.

trivettj
Posts: 55
Joined: Mon Sep 03, 2012 10:01 pm
Location: banner elk north carolina

Re: Mounting Water Glass

Postby trivettj » Fri Nov 17, 2017 12:39 pm

I probably should try to raise my glass then it's on a Tom artzberger rgs 20 also. I put the bottom of the brass glass holder 3/4 inches above the crown sheet so I will need to remeasure and see how far up the actual glass is from the crown sheet cause I really don't want any problems I thought I was being safe putting it that far up but that's what I get for thinking.

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 1:09 pm

That should be fine as long as you remember to keep a little more water in on a grade; I don't think I would move it.

User avatar
Fender
Posts: 2411
Joined: Wed May 02, 2007 8:33 pm
Location: Chattanooga TN

Re: Mounting Water Glass

Postby Fender » Fri Nov 17, 2017 2:27 pm

From my experience, there are more problems with the water level when starting downgrade. Usually the engine has been working hard with a hot fire going upgrade, then you stop working steam, switch to a downgrade, the safeties lift, and the water rushes to the front of the boiler and out of the water gauge.
But in terms of an upgrade situation, the water level over the crownsheet could be deceptive. I measured the firebox for an RGS 20 to make new grates, and it was 4”W x 16”L, I believe. So using 18” for the distance from the front of the firebox to the water gauge, and a five percent upgrade, the water level at the front of the firebox would be 18 x 5 / 100 = 0.9” lower than the level in the water gauge, quite a difference.
Dan Watson

Kimball McGinley
Posts: 654
Joined: Wed May 31, 2006 2:13 pm
Location: Laguna Niguel CA

Re: Mounting Water Glass

Postby Kimball McGinley » Fri Nov 17, 2017 3:24 pm

I think maybe trivettj could just slip a short piece of brass tube around the glass to "raise" the lowest visible point? Maybe a touch of superglue to hold it down?

User avatar
Marty_Knox
Posts: 1216
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Mounting Water Glass

Postby Marty_Knox » Fri Nov 17, 2017 3:58 pm

Fender wrote:But in terms of an upgrade situation, the water level over the crownsheet could be deceptive. I measured the firebox for an RGS 20 to make new grates, and it was 4”W x 16”L, I believe. So using 18” for the distance from the front of the firebox to the water gauge, and a five percent upgrade, the water level at the front of the firebox would be 18 x 5 / 100 = 0.9” lower than the level in the water gauge, quite a difference.

Which is why I mounted my water glass so the lowest reading is 1 5/16" higher than the crown sheet at the back, so I still have 1/2" of water at the front on a 5% grade.

Pontiacguy1
Posts: 683
Joined: Thu Apr 26, 2012 10:15 am
Location: Tennessee, USA

Re: Mounting Water Glass

Postby Pontiacguy1 » Fri Nov 17, 2017 4:59 pm

I have done what you suggested to a locomotive before... Added a ring of brass around the bottom of the glass so that it would raise the lowest visible point. It worked fine and provided the margin of safety that I was looking for.


Return to “Live Steam”

Who is online

Users browsing this forum: cbrew, Yahoo [Bot] and 14 guests