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Re: Vaporizing 1 pipe steam?
Please keep in mind that there is a world of difference between vapour systems, which may or may not operate in a vacuum, and vacuum assisted systems.
The key to vapour systems is in very small, tightly controlled pressure differentials between the steam main supplies and the dry return lines. These differentials are usually on the order of 4 to 6 ounces per square inch differential pressure. The absolute pressure at which they run has nothing to do with the characterisation. The absolute pressure in the system at any given time does affect at what temperature the vapour will be produced, of course. This is where the "dying coal fire" notion comes in -- as the fire died, the system absolute pressure dropped below atmospheric and, correspondingly, the temperature at which the water boiler also dropped (so did the temperature at the radiators at which it condensed) and so it was possible to make use of the lower temperature heat output of a low or dying coal fire.
The tightly controlled differential pressure makes it possible to control, equally tightly, the relative heat output of the various radiators using calibrated valves or orifices, and sometimes makes it possible to do away with steam traps. Not always, however, as steam traps were and are common on vapour systems to prevent any possibility of steam getting into the dry returns -- which would upset the pressure differential.
The vacuum vents which were used, of which the Hoffman 76 is an example (it is still produced, by the way, if you have the cash to pay for it), allowed this drop in absolute pressure while not admitting air to the system.
Many of them had -- and have -- various ingenious devices to ensure that the pressure differential stays low -- the dreaded Hoffman Differential Loop is one -- to ensure that the condensate could, in fact, return to the boiler without difficulty.
Vacuum assisted systems are a different critter altogether, and are much more akin to one pipe systems. In general, the vacuum assist was used to evacuate air more rapidly -- potentially at a lower absolute pressure in the boiler, but not necessarily -- from the system.
Vacuum assisted systems are not particularly fussy about vacuum leaks -- the vacuum pump can handle the leakage, or should be able to. Depending on the vacuum pump type, however, they can be very unhappy if they get steam in the lines to the vacuum pump. Vapour systems don't care about vacuum leanks, unless they are intended to drop below atmospheric pressure on cooling, in which case they certainly do care, and maintaining a large system to be really vacuum tight is an ongoing battle.
A couple of other considerations. First, there really isn't enough residual heat in even a large cast iron boiler to make much difference unless one is going for that last tenth of a percent of efficiency. Second, controlling the absolute pressure at which the boiler operates requires sensitive devices, such as a vaourstat, maintained and mounted so that it can function properly. If one wanted to run a vapour system at sub-atmospheric pressures (i.e. a "vacuum") -- which has some interesting theoretical advantages -- the control mechanism has to be sensitive to the pressure differential between the mains and the dry returns. This can, of course, be done, and was in the days of coal by differential sensing damper controls (the efficiency on part fire was horrible, by the way) -- but it is not how modern controls work. It would be advantageous if one could design a modulating oil or gas fired burner which
was differential pressure sensitive. I haven't seen one.
Bottom line: don't confuse vapour steam systems with vacuum assisted steam systems. Not the same animal at all.
The key to vapour systems is in very small, tightly controlled pressure differentials between the steam main supplies and the dry return lines. These differentials are usually on the order of 4 to 6 ounces per square inch differential pressure. The absolute pressure at which they run has nothing to do with the characterisation. The absolute pressure in the system at any given time does affect at what temperature the vapour will be produced, of course. This is where the "dying coal fire" notion comes in -- as the fire died, the system absolute pressure dropped below atmospheric and, correspondingly, the temperature at which the water boiler also dropped (so did the temperature at the radiators at which it condensed) and so it was possible to make use of the lower temperature heat output of a low or dying coal fire.
The tightly controlled differential pressure makes it possible to control, equally tightly, the relative heat output of the various radiators using calibrated valves or orifices, and sometimes makes it possible to do away with steam traps. Not always, however, as steam traps were and are common on vapour systems to prevent any possibility of steam getting into the dry returns -- which would upset the pressure differential.
The vacuum vents which were used, of which the Hoffman 76 is an example (it is still produced, by the way, if you have the cash to pay for it), allowed this drop in absolute pressure while not admitting air to the system.
Many of them had -- and have -- various ingenious devices to ensure that the pressure differential stays low -- the dreaded Hoffman Differential Loop is one -- to ensure that the condensate could, in fact, return to the boiler without difficulty.
Vacuum assisted systems are a different critter altogether, and are much more akin to one pipe systems. In general, the vacuum assist was used to evacuate air more rapidly -- potentially at a lower absolute pressure in the boiler, but not necessarily -- from the system.
Vacuum assisted systems are not particularly fussy about vacuum leaks -- the vacuum pump can handle the leakage, or should be able to. Depending on the vacuum pump type, however, they can be very unhappy if they get steam in the lines to the vacuum pump. Vapour systems don't care about vacuum leanks, unless they are intended to drop below atmospheric pressure on cooling, in which case they certainly do care, and maintaining a large system to be really vacuum tight is an ongoing battle.
A couple of other considerations. First, there really isn't enough residual heat in even a large cast iron boiler to make much difference unless one is going for that last tenth of a percent of efficiency. Second, controlling the absolute pressure at which the boiler operates requires sensitive devices, such as a vaourstat, maintained and mounted so that it can function properly. If one wanted to run a vapour system at sub-atmospheric pressures (i.e. a "vacuum") -- which has some interesting theoretical advantages -- the control mechanism has to be sensitive to the pressure differential between the mains and the dry returns. This can, of course, be done, and was in the days of coal by differential sensing damper controls (the efficiency on part fire was horrible, by the way) -- but it is not how modern controls work. It would be advantageous if one could design a modulating oil or gas fired burner which
was differential pressure sensitive. I haven't seen one.
Bottom line: don't confuse vapour steam systems with vacuum assisted steam systems. Not the same animal at all.
Re: Gas gun in oil burner and Chimney Liner
All chimneys must be suitable for the class of service. If you search this site, you will find me repeating this several dozen times. The code requires a liner. The liner must be properly sized and intact. Terra cotta liners are never installed properly, never hold up, run cold and sweat, and the mortar is incorrect so it erodes even if properly placed, which is rare.
The industry std. is NFPA 211. In Ch 15, you will find levels of inspection. You need a Level II internal inspection by a qualified agency. That will 100% reveal you need a liner if they're doing their jobs.
Many great points above by the guys on sizing, efficiency, condensation, etc. The liner not only contains corrosion and erosion, it sizes the flue to the appliance and, being low mass, heats up quickly to minimize backdrafting at startup. Your chimney sweep should have recommended a level II- call him.
If you check into your state and utilities, you may find incentives to do the CAT IV condensing unit now rather than wait. That money for the liner would go a long way to defraying that cost plus you begin saving on energy costs.
The industry std. is NFPA 211. In Ch 15, you will find levels of inspection. You need a Level II internal inspection by a qualified agency. That will 100% reveal you need a liner if they're doing their jobs.
Many great points above by the guys on sizing, efficiency, condensation, etc. The liner not only contains corrosion and erosion, it sizes the flue to the appliance and, being low mass, heats up quickly to minimize backdrafting at startup. Your chimney sweep should have recommended a level II- call him.
If you check into your state and utilities, you may find incentives to do the CAT IV condensing unit now rather than wait. That money for the liner would go a long way to defraying that cost plus you begin saving on energy costs.
Re: Burnham Oil Burner creating tons of soot
I worked with a guy years ago who insisted on really wrenching down on the nozzle when servicing the burner. He would back one wrench and really lean on the other stretching's the threads in the adapter and causing a leak through the threads especially at an elevated pressure. It would show up only after enough oil has dripped into the burner tube and out into the chamber. If the burner tube was cleaned with every attempt to solve the issue it would take a day or so to declare it's self. This is something I've seen a number of time since. What you are describing rings that bell for me. An indicator for me was a nozzle that turned out normally for a few threads and then started to bind or gaul the rest of the way.
Just a thought and something I'd look at.
Good luck.
Just a thought and something I'd look at.
Good luck.
Grallert
2
Re: Install of the Year!
Doesn't matter, no way we will know unless you want to call those numbers. No one puts stickers assuming it will be blasted on the internet, it's for the homeowner to know who to call current/future.
I judge installers and servers on how they place stickers.
If they place it randomly and crooked, I automatically assume their work is just as sloppy.
I judge installers and servers on how they place stickers.
If they place it randomly and crooked, I automatically assume their work is just as sloppy.
dko
2
Re: Burnham Oil Burner creating tons of soot
From the Beckett OEM Spec Guide:
Model Burner Nozzle Alt. Nozzle Pressure Air settings Head
MPO115 AFG 0.65 X 45°B 0.65 X 45°B* (H) 150 S-6 / B-0 L2
MPO115 AFG 0.60 X 45°W 0.60 X 45°B 180 S-5 / B-0 L2
Note that they use a smaller nozzle with the higher pressure.
Model Burner Nozzle Alt. Nozzle Pressure Air settings Head
MPO115 AFG 0.65 X 45°B 0.65 X 45°B* (H) 150 S-6 / B-0 L2
MPO115 AFG 0.60 X 45°W 0.60 X 45°B 180 S-5 / B-0 L2
Note that they use a smaller nozzle with the higher pressure.
Re: Burnham Oil Burner creating tons of soot
I’d really start over with all the settings and parameters, especially insertion depth, z dimension, and overfire draft. 1/4” on the z is the difference between clean and soot city.
I have a first gen MPO. Set up perfectly it hasn’t been cleaned in 4 years, and doesn’t need it.
I have a first gen MPO. Set up perfectly it hasn’t been cleaned in 4 years, and doesn’t need it.
Re: Burnham Oil Burner creating tons of soot
Do you ever notice that when people say the combustion numbers look good they never list them. Draft. smoke, CO(lightoff, Run, Shutdown), O2, Flue Temp
Re: Can you use type M copper pipe?
According to their 2021 NSPCNJ allows M copper for domestic?realliveplumber said:Yes, M is approved in NJ. For potable and hydronic.
The wall thickness is the difference. L has a thicker wall than M.
https://epubs.iapmo.org/NSPC/NJ2021/
yes, and looks to have always been allowed in NJ even in prior code adoptions.
But will say, I have plenty of NJ plumbers and they still only buy type L pipe.
dko
1
Re: Wicked old two pipe, no traps
IIRC, boilers for Molines should be sized to only 80% of the radiation. That's what the radiator orifices are sized for. If the system doesn't have the original adjustable orifice valves, then I'd orifice it to the current heating needs. This would allow you to downsize the boiler to the current heating load ( and not the radiation load). Read all the Moline info you can get.
Lowering the water line should help you, as you get more b-dimension... everything returns back into the water level. Keep in mind that there are 3 pipes on this system, supply, return and condensor pipe coming out of the Moline ( venturi) fitting up on the ceiling. The length on this condensor pipe is in the literature....about 35 feet IIRC. This condensor line, along with the Moline fitting, create a vacuum on the return to give incredible distribution. The condensor line is sized to prevent steam from reaching the end of the pipe at the proper maximum operating pressure (8oz). DO NOT INSULATE THIS PIPE AND USE AN OUNCES VAPORTSTAT. The saucer shaped device is a very sensitive check valve to allow the system to go into vacuum. It has a diaphargm on some type ( I haven't ever pulled one apart) which is probably shot and should be replaced with a teflon ball check valve with no spring ( apollo makes them).
Lowering the water line should help you, as you get more b-dimension... everything returns back into the water level. Keep in mind that there are 3 pipes on this system, supply, return and condensor pipe coming out of the Moline ( venturi) fitting up on the ceiling. The length on this condensor pipe is in the literature....about 35 feet IIRC. This condensor line, along with the Moline fitting, create a vacuum on the return to give incredible distribution. The condensor line is sized to prevent steam from reaching the end of the pipe at the proper maximum operating pressure (8oz). DO NOT INSULATE THIS PIPE AND USE AN OUNCES VAPORTSTAT. The saucer shaped device is a very sensitive check valve to allow the system to go into vacuum. It has a diaphargm on some type ( I haven't ever pulled one apart) which is probably shot and should be replaced with a teflon ball check valve with no spring ( apollo makes them).
