Author Topic: Help with fittings on a Boiler  (Read 3424 times)

Offline paul gough

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Re: Help with fittings on a Boiler
« Reply #75 on: November 12, 2017, 09:09:06 PM »
Hi Thomas, Thanks for the PM and link, been a bit wobbly lately so have a lot of catching up to do. Regards Paul Gough.

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #76 on: November 12, 2017, 10:51:07 PM »
Hi Thomas, Thanks for the PM and link, been a bit wobbly lately so have a lot of catching up to do. Regards Paul Gough.

Hello Paul,

You are more than welcome. Sorry to hear that you haven't been up to speed lately.

Have a great day,
Thomas

Offline kvom

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Re: Help with fittings on a Boiler
« Reply #77 on: November 13, 2017, 03:02:35 PM »
My only comment on this build is that doing pressure testing with air vs. water isn't allowed at my club.  The hydro test requires that the boiler be full.  Failure is much less dramatic in this scenario.

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #78 on: November 13, 2017, 07:00:34 PM »
My only comment on this build is that doing pressure testing with air vs. water isn't allowed at my club.  The hydro test requires that the boiler be full.  Failure is much less dramatic in this scenario.

Hi kvom,

Yes I understand and do agree with you 100%. However the underwater test was only at 50psi and was just to confirm that all the silver solder joints had no leaks. I later plugged all of the openings but the one air-in with the globe valve. Then filled it full of water and submerged it again and applied 90psi and held it for 30-minutes. I closed the valve and disconnected it from my air line to confirm that the valve was also holding OK.

The ASTM code shows the actual burst pressure on 2-1/2" Type "L" pipe is over 3000 pounds, so my main concern was not with the pipe or fittings but with the silver soldered joints. I wanted to be sure the Steam Trap was completely "finished" before attaching it to the Boiler.

Thank you and I appreciate your comment, this is what makes a Forum great.

Have a great day,
Thomas

Offline steamboatmodel

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Re: Help with fittings on a Boiler
« Reply #79 on: November 14, 2017, 06:07:42 PM »
Since the steam trap is at boiler pressure, instead of draining it to atmosphere would it not be better to connect it back to the boiler?
Gerald.
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Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #80 on: November 14, 2017, 09:09:11 PM »
Since the steam trap is at boiler pressure, instead of draining it to atmosphere would it not be better to connect it back to the boiler?
Gerald.

Hello steamboatmodel,

I have never seen that done before, but maybe with a check valve in the discharge line it could be done. With equal pressure from the bottom of the Steam Trap and the return line mounted above the water level, I'm not sure if you could "push" the liquid (water) back up that high. Gerald, I just don't know, maybe someone will tell us if it can be done and how.

Thank you and have a great day,
Thomas

Offline MJM460

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Re: Help with fittings on a Boiler
« Reply #81 on: November 15, 2017, 03:31:27 AM »
Hi Thomas, there is no reason not to run the liquid outlet back to the boiler, if it was a full size boiler, the whole device would be inside the steam drum with the outlet just running to the bottom of the drum.  But it would take some ingenuity to fit one into a model.  No need for a check valve, in fact better without it.  The only critical thing for running it back to the boiler is that the highest liquid level and the highest hole in the centre tube in your separator must be above the liquid level in the full boiler.

If I understand your design, the steam from the boiler goes in the top, flows down and out through the holes in the centre tube and completes a 180 degree change of direction to flow back up to the outlet in the side near the top of the outside shell.  That 180 degree change of direction is critical to the good separation of the liquid phase.  If you have some good insulation, there should be no significant condensation, it is mostly carryover from the boiler, and may be continuous until the boiler level gets down a bit.  Or your steam turret may minimise it if I remember your boiler design correctly.   You don't seem to have much volume in the separator to accumulate water below the top holes in the centre tube, so better to drain it back to the boiler continuously.

The return to the boiler, (near the bottom, not above the liquid level), acts like a u-tube.  If some water builds up on one side, it will flow around the bottom until the levels are equal, or out at the top of the other side into the boiler if it reaches that first. I am sure you know the principal.  The pressure at the liquid surface on both sides is the same, so the flow is driven purely by the differences in level.  If you put a check valve you will need a few extra inches of height to provide the pressure to lift the ball.  You can work it out from the weight of the ball divided by the area of the hole you drill for the seat.  I think I would run the u-tube down as much as you have space for, then back up to the bottom of the boiler to the boiler inlet to make a clear "U", not just a single 90 degree elbow.

I know you called it a steam trap and I have called it a separator.  Yo'all often use different terms to the rest of the English speaking world, it is just terminology, I can deal with that.  In fact though, I should change that, I have found that in the Deep South, you use the same words, you just say them differently.  It is further North that they actually use different terms, making conversation more confusing.  And anyhow, you are all way, way North to us!  So a little mystery to be discussed another time.

Looking forward to seeing the operation of your separator.

MJM460

The more I learn, the more I find that I still have to learn!

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #82 on: November 15, 2017, 11:33:35 AM »
Hi Thomas, there is no reason not to run the liquid outlet back to the boiler, if it was a full size boiler, the whole device would be inside the steam drum with the outlet just running to the bottom of the drum.  But it would take some ingenuity to fit one into a model.  No need for a check valve, in fact better without it.  The only critical thing for running it back to the boiler is that the highest liquid level and the highest hole in the centre tube in your separator must be above the liquid level in the full boiler.

If I understand your design, the steam from the boiler goes in the top, flows down and out through the holes in the centre tube and completes a 180 degree change of direction to flow back up to the outlet in the side near the top of the outside shell.  That 180 degree change of direction is critical to the good separation of the liquid phase.  If you have some good insulation, there should be no significant condensation, it is mostly carryover from the boiler, and may be continuous until the boiler level gets down a bit.  Or your steam turret may minimise it if I remember your boiler design correctly.   You don't seem to have much volume in the separator to accumulate water below the top holes in the centre tube, so better to drain it back to the boiler continuously.

The return to the boiler, (near the bottom, not above the liquid level), acts like a u-tube.  If some water builds up on one side, it will flow around the bottom until the levels are equal, or out at the top of the other side into the boiler if it reaches that first. I am sure you know the principal.  The pressure at the liquid surface on both sides is the same, so the flow is driven purely by the differences in level.  If you put a check valve you will need a few extra inches of height to provide the pressure to lift the ball.  You can work it out from the weight of the ball divided by the area of the hole you drill for the seat.  I think I would run the u-tube down as much as you have space for, then back up to the bottom of the boiler to the boiler inlet to make a clear "U", not just a single 90 degree elbow.

I know you called it a steam trap and I have called it a separator.  Yo'all often use different terms to the rest of the English speaking world, it is just terminology, I can deal with that.  In fact though, I should change that, I have found that in the Deep South, you use the same words, you just say them differently.  It is further North that they actually use different terms, making conversation more confusing.  And anyhow, you are all way, way North to us!  So a little mystery to be discussed another time.

Looking forward to seeing the operation of your separator.

MJM460

Howdy pardner,  MJM460

Yep, you and the rest of the speaking humans on this earth “shore-do” speak funny.... My old good friend Harry Taylor down in Tasmania call aluminum “al-u-minimum”? Before he passed away, he and I talked every day on ham radio and over many years we actually learned how to understand each other, or should I say, “interpret”......he he he

Thanks for explaining how to loop the condensate from a steam trap back into a boiler. My exposer to steam traps were in use in the petrochemical industry and they were installed in a fashion to discharge outside of the source. They were mostly of an “automatic” design and installed at the lowest point of the steam line.

In the operation of my boiler, I would suspect that in a normal running period (30 minutes to one hour) that the boiler will produce very little condensate and I believe it will be simpler to just discharge to the same pan as the safety valve overflow uses.

I am attaching Part-2 of my build on the trap showing the “plumbing” connected to the trap. When everything is completed, the Boiler with the Steam Trap will be mounted on a roll around cart and the main steam line will be run overhead up to the top level. I will install the Power Control Unit permanently along with various accessories, and whatever Steam Engine that I am running at the time, on the top level. You can see that the discharge line is at the lowest point of the steam line and should be efficient.

Again thank you for all the good advice and help.

You have a great day now, ya-hear.
Thomas



Offline MJM460

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Re: Help with fittings on a Boiler
« Reply #83 on: November 16, 2017, 09:09:50 AM »
Ok, Thomas, we are talking the same language, just a minor difference in usage.  Though only two m's in Aluminium.  The story here goes that some executive in an American aluminium company spelt it wrong in the early days, and no one had the courage to correct him.  Or perhaps no one else noticed.  The extra "i" is consistent with other element naming in the periodic table but you folk are unlikely to change.  It would be a huge job for not much benefit.  So it just remains another linguistic difference.

I am quite  familiar with the automatic traps, which as you say discharge to a lower pressure return system or a drain.  I have usually just put a cap in the end of a vertical pipe, with the outlet to the turbine on the side a little above.  Then an automatic trap on the bottom.  But in a full size plant we are dealing with much more condensate, as you know.  The automatic steam trap is quite important, as I have spent much more time in commissioning than in normal operation, so more than the normal number of stop - start operations, which also means more condensate in the headers.  Once the machine is running 24/7 for most of the time, it would not surprise me if they are removed the first time they give trouble, as with a continuous flow of steam they are hardly necessary, and the manual valve for the occasional startup is adequate.

For your separator, the only thing I would suggest is that steam outlet stays horizontal to the engine outlet, or runs up to the engine, so that any condensate formed in that section while the engine is stationary runs back to the trap instead of into the engine.  No point in going to the effort of making the trap and then draining the condensate into the engine anyway.  More important in the model world than larger scale, as relatively, our engines spend more time stationary.

Looking forward to seeing the complete setup is action with an engine on the trolley.

MJM460
The more I learn, the more I find that I still have to learn!

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #84 on: November 16, 2017, 10:30:14 AM »
Ok, Thomas, we are talking the same language, just a minor difference in usage.  Though only two m's in Aluminium.  The story here goes that some executive in an American aluminium company spelt it wrong in the early days, and no one had the courage to correct him.  Or perhaps no one else noticed.  The extra "i" is consistent with other element naming in the periodic table but you folk are unlikely to change.  It would be a huge job for not much benefit.  So it just remains another linguistic difference.

I am quite  familiar with the automatic traps, which as you say discharge to a lower pressure return system or a drain.  I have usually just put a cap in the end of a vertical pipe, with the outlet to the turbine on the side a little above.  Then an automatic trap on the bottom.  But in a full size plant we are dealing with much more condensate, as you know.  The automatic steam trap is quite important, as I have spent much more time in commissioning than in normal operation, so more than the normal number of stop - start operations, which also means more condensate in the headers.  Once the machine is running 24/7 for most of the time, it would not surprise me if they are removed the first time they give trouble, as with a continuous flow of steam they are hardly necessary, and the manual valve for the occasional startup is adequate.

For your separator, the only thing I would suggest is that steam outlet stays horizontal to the engine outlet, or runs up to the engine, so that any condensate formed in that section while the engine is stationary runs back to the trap instead of into the engine.  No point in going to the effort of making the trap and then draining the condensate into the engine anyway.  More important in the model world than larger scale, as relatively, our engines spend more time stationary.

Looking forward to seeing the complete setup is action with an engine on the trolley.

MJM460

G' day to you MJM460

OK I sure missed that point, however that will be a very easy fix because I have not mounted the Boiler to the timbers. The Boiler will come out of the cart today while I work on installing the sight glass and I can make the required plumbing changes.

I surely do appreciate your suggestion and help.

Have a great day,
Thomas

 

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #85 on: November 18, 2017, 03:40:07 PM »
Hello to all,

Attached is a photo of the cart that the Boiler will be mounted on. I applied two heavy coats of black Bed Liner material to the bottom tray for protection. As soon as I have finished installing the sight glass I can then install the top tray and the timbers. The Power Control Unit, accessories and what ever steam engine that I am running at the time will be mounted on this top tray. I have repositioned the steam out to now be horizontal with the tank as suggested by MJM460.

Have a great day,
Thomas

Offline Ye-Ole Steam Dude

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Re: Help with fittings on a Boiler
« Reply #86 on: Today at 04:14:43 PM »
Hello everyone,

Little more progress on the Boiler and the Roll Around Cart completed. Got the sight glass installed so I was able to mount the Boiler on to the timbers and get that back into the cart. Installed the Top Shelf and the timber decking and made this removable. I raised the decking so that I can route wiring or plumbing “under ground” if needed. In time I might have several steam outlets in various locations and all that plumbing can be installed below the decking (under ground) to keep the surface as clean as possible.

Next I will hard plumb using copper tubing, the steam line up from the steam trap to a fixed location at the top shelf. Also will hard plumb the drain line from the steam trap to the discharge location.

I am thinking about building a “pump house” to camouflage the Power Control Unit. It could be raised up or hinged over to have access to the PCU to turn it on and off or make adjustments. Have to think a bit more on that.

Have a great day,

Online crueby

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Re: Help with fittings on a Boiler
« Reply #87 on: Today at 06:49:19 PM »
I really like that setup with the cart!