Harris style Gauge Glass assembly

[steamer]

Hi,

Was wondering if anyone had built a Gauge Glass assembly as per Harris's book. You know the ones that you can change out the tube while under steam, and the tube fits inside, instead of straddling...

I am thinking of building one for Rushforth this winter.....What do ya think

The commercial "small scale" stuff sucks!

Dave

 

[Maryak]

Dave,

I have not built one but it seems like a wise move to me.

Best Regards
Bob

 

[Dan Rowe]

Hi Dave,
I have not built one but my assumption is that you are talking about the one piece body valve Fig. 6-9 in K.N. Harris "Model Boilers & Boilermaking".

And yes the shut off arangement will allow to change the glass under steam but why bother with a model? If it was nessary to keep steam up why not make a Klinger flat plate type and have a spare made up to fit with unions after the shut off valves?

The idea of a one piece body makes a lot of sense to me as the construction does look harder than two fittings.

Dan

 

[steamer]

Actually,It's for my boat. The "Commercial" one is just really poor and always leaks and has to be removed completely to change the glass. It was intended for 3" scale stuff, but I can't stand it anymore.

Going to look at American Model Engineering Supply's unit and replumb unless you boys across the pond have a better solution. Full size practice....as much as I like them...just doesn't fit on my very small boiler.

I need about 5 1/2" of glass.

By the way, Rushforth passed hydro yesterday.


Dave

 

[steamer]

Yes Dan, that is the figure if memory serves me.

Dave

 

[Maryak]

Dave,

Just a thought but small locos, 5-10hp stationary boilers and small paddlers all use a glass around 6." The good thing about these types are that the glass and the cone washers to suit are readily, (if expensively), available. Try the museums or boiler repair joints they are probably tripping over surplus ones.

Best Regards
Bob

 

[Dan Rowe]

Hi Dave,
I should have figured it was for your boat. Here is a link to a commercial valve that looks like it might be suitable.
They say they have other stuff in stock so there might be more options.
http://livesteamsupplies.com/livesteamsupplies_002.htm

Dan

 

[Dan Rowe]

Dave,
Here is another source, the heavy pattern has more options for pipe thread size.
http://www.boilersupplies.com/water-gauges/water-gauges.html

Dan

Edit: I checked for more gauges because I was having trouble understanding how a ball check was going to work in this application. The linked site has a instalition manual with a drawing and I am still missing how the ball check will work. The first page in the Do Not section states that the ball checks can give incorrect readings with system surges, so I am thinking for marine use the ball checks should be removed.
http://www.boilersupplies.com/gageglass/liquidlevel.pdf
Dan

 

[steamboatmodel]

It has been a while since I have operated full size boilers, but if I remember correct you had to close and then open the shut off valves if you suspected that you were not getting a correct reading. The shutoff valves have a tip on them that when the valve is closed forced the ball off its seat, when you opened the valve the pressure equalized around the ball and it floated off its seat. If the glass broke the pressure and flow seated the valve provided you had opened the vale fully.
Regards,
Gerald.

 

[steamer]

Thanks Dan!

Code is 1/2" npt minimum ....so I'll have to remake my water column to match. No worries there

If I'm doing that I'll go for the ball check and the guard . The glass is way too close to my port side passenger...and me for that matter.

This is one area of the build I have never been happy about. IT GONE.

Thanks Again
Gerald your right about the safety checks. That solves the blow out problem. I won't know if the checks are an issue in a small boat that rocks a bit....guess I'll find out.

But a big honking glass guard is going on!

Dave



Dave

 

[Dan Rowe]

Gerald,
Thanks for the explanation. I have rebuilt several gauge glass assembles as a marine engineer but check valves are not used on ships as there is no way to prevent storm surges which will lead to issues. I found a better drawing that shows the arrangement much better.
http://www.ksr-kuebler.com/website/dyndata/1017_15E.pdf

Dave,
When I read check valve my mind went wow that is a good idea then I did a double take.... I think you can have the best of both worlds. This is how I would rig the valves, I would note the position of the valve where the valve rod holds the ball between the valve seats and mark the top spoke of the valve wheel RED. This way you could open the valve fully for normal operation and have a known setting to disable the check feature if rough weather made that necessary. The blow down could be used to check both the emergency and normal fully open safety setting with steam up.

Dan

 

[steamer]

Hi Dan,

Code requires the checks, but if they're a hassle or restrict the glass in anyway...they're gone.

I looked at a reflex glass...but man are they heavy! I'm worried about bouncing the boat down the road with 15 pounds hanging on the plumbing!

I'll let you know how I make out.

Dave

 

[Dan Rowe]

Code requires the checks,

Hi Dave,
You must be refereeing to the ASME Code, USCG Code is a modified version of the ASME Code. See:
http://cfr.vlex.com/vid/01-columns-gauge-cocks-gauges-19848428

There is no mention of check valves but as I read it the gauge has to be in continuous operation while the boiler is steaming and check valves can cause intermitten operation on a roll.

I once was standing next to a gauge when it blew...I know for a fact that there was not a check valve. I secured the quick closing valves and checked my drawers.

Cheers Dan

 

[steamer]

Hi Dave,
You must be refereeing to the ASME Code, USCG Code is a modified version of the ASME Code. See:
http://cfr.vlex.com/vid/01-columns-gauge-cocks-gauges-19848428

There is no mention of check valves but as I read it the gauge has to be in continuous operation while the boiler is steaming and check valves can cause intermitten operation on a roll.

I once was standing next to a gauge when it blew...I know for a fact that there was not a check valve. I secured the quick closing valves and checked my drawers.

Cheers Dan

;D

Yes ASME code that is....inland water ways not patroled by the USCG are covered under state law.

Otherwise...under 40 feet, not for commercial service, and the USCG could care less as long as I have my life preservers on board!

The Motor boat act......IIRC.

Haven't been that close to a glass when it's blown...been next to some feed checks when they back flowed into the hotwell though.....pretty fountaine!. ;D...and you can watch the gauge glass water level drop like a stone! The Cheif didn't believe me at first...then two weeks later it happened to him too!
New 600 pound checks went in the next day! :big:

Dave

 

[Maryak]

Guys,

Under normal conditions the balls float and only set hard against their seat when there is a massive pressure drop, i.e. broken glass. I have seen balls which are sluggish in operation due to a build up of sludge in the water columns and then into the glass mountings when blowing down the glass. This is mostly due to poor boiler maintenance,higher than permissible levels of TDS in the boiler water resulting in carry over and dare I say it priming. Poor maintenance can also result in the balls being dropped, lost in the bilge and not replaced. I have not seen a gauge glass give false readings due to the balls, even in the extreme conditions of riding out a typhoon for up to 5 days at a stretch.

When a glass breaks without check valves it's no big deal if you have remote actuators fitted to the shut offs but if you have to fight your way up to the glass through the heat and steam to shut the glass off some 10-30ft above you, it becomes a less than pleasant experience.

I guess what I'm trying to say is fit the damn balls.

Best Regards
Bob

 

[steamer]

;D
30 feet! I'm less than 3!...more like a foot!
I planned on it anyway Bob...no worries.

Dave

 

[steamer]

check out this gauge glass protector....sexy and functional!

Dave

http://www.chanterbiomed.co.uk/boiler_spares/protectors.html

 

[steamer]

definitely this is in the running! The B2

Dave

http://www.chanterbiomed.co.uk/boiler_spares/gunmetal_reflex_gauge.html

 

[steamer]

Or this

http://www.penberthy-online.com/literature/gages_and_valves/IOM - 2969.pdf
Dave

 

[Maryak]

The 1st link is the type I was referring to in my pm.

Typhoon Freda somewhere off Hong Kong June 1971

Best Regards
Bob