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Re: Steam device to be identified
@mattmia2 " What is this tube, where does it go? "
This tube ? Maybe the radiator supply.
Multiple pressure controls the lower two looks like Vaporstat size diaphragm diameter.
109A_5
Re: Steam device to be identified
@Steamhead It appears to vent the air out, it has to go through a bit of water at least the height of the boiler water, Figure 205. It makes it harder for the air to get back in resulting in a vacuum for faster steam propagation with the next cycle.
109A_5
Re: Steam device to be identified
The regulating valve isn't that complicated. Basically, in a 2-pipe steam system there has to be a way to keep steam out of the dry (overhead) returns, which are only sized to carry returning condensate (water) and air. There are several methods, steam traps being one, but in a Tudor system the radiator valve contains a restriction, or orifice, that will only let a certain amount of steam enter the radiator at a certain design pressure. So, if the steam pressure is kept to that certain point, there will not be enough steam entering the radiator to fill it completely and enter the dry return. In the valves described, the installer sets the restrictor, and after that the owner cannot open the valve any further.
One of the nice things about this method is its lack of moving parts that will need servicing.
So, how does the air get out of this system? Basic principle is, steam will not go where there is air. In figure 205, a pipe leaves the "safety valve" and exhausts the air outside. Is it possible this system once had such an air pipe?
A couple other things to check:
1- blocked return line between the "safety valve" and the boiler, and
2- boiler pressure getting too high, which can force the returning water out the vent.
Re: Steam device to be identified
I’m with Steamhead: boiler-return trap. Do you have photos of a radiator? Close-up of the supply and return sides would be helpful. And welcome!
Re: Replacing Electrodes on Beckett AFG Oil Burner
The fuel pump cover bolts takes a 5/32 Allen head. And no smoke or anything odd that you could tell? Awesome. Looks like you got it handled.
HVACNUT
Re: Replacing Electrodes on Beckett AFG Oil Burner
Those are the cleanout ports for the heat exchanger (HX). The proper cleaning tool is a 1-1/2 diameter horse hair brush with a 36" to 42" handle in order to wrap around the curve of the HX then you vacuum what falls to the bottom with a flexible 1.12" soot snorkel. Cleanout Brush.
As far as the fuel pump is concerned you will need a replacement gasket on hand to service the strainer, or you can just purchase a replacement strainer that comes with a gasket. Suntec 3779901 cover gasket or Suntec strainer S160-14
Or you can get the same parts with the RW Beckett name on them for more money. Beckett S160-14
Re: Steam device to be identified
@jeje59350 , look at the article I linked to. In figure 205, a device is shown which appears to be similar in connection and purpose to yours. I therefore believe your device is a safety valve, especially since I do not see a safety valve on the boiler- at least not one that looks like those we use here.
Your photo 103123 shows a radiator that looks similar to the Rococo model that was made here up until 1920, by American Radiator Co. I believe American Radiator had a subsidiary in France then, and I'll look that up later. This would mean the radiator is probably original to the building.
Photo 103111 shows a device on the outlet of a radiator- what is it?
How does air get out of the system?
Steam device to be identified
Hello.
I'm working in Paris, France. There, we have few old steam central heating system still working in some old housing building.
Few people here know well about these systems.
Would you be able to identify the device that is surrounded in the enclosed picture?
When the maintener increases the steam pressure, the steam goes out of this device from the top connection as if it was a kind of safety valve but it does really not look like the one I am used to see. Is it one?
FYI decades ago, it was a coal boiler.
I apologise for my weak English.
Jérémie
Re: Radiant heat with oil? Can it be done?
As I noted above, short cycling is not a concern with oil burners. They're commonly configured to maintain boiler temperature when idle with zero flow. With a fifteen gallon boiler and a 20F swing, a 100K BTU/hr boiler only needs to run for about 90 seconds, they seem to be able to do this for decades without ill effect. Any heating load is going to give longer run times.
Where you typically run into trouble with small loads — and this is not specific to oil burners — is with the distribution, specifically getting a circulator to work properly both with tiny loads and the full capacity of the boiler when it's needed. The solution is primary/secondary piping or a similar variant.
Re: Radiant heat with oil? Can it be done?
On buffer tanks, if you will permit me. And boilers. The problem is a practical one: matching the boiler output to the system input requirements. This is a common problem with steam systems, as modulating the temperature of the emitters is, while not impossible, impractical in most cases. It is much less of a problem with hydronic heat, as it is entirely feasible to modulate the emitter temperature to anything needed to match the load, and thus modulate the system power requirement from the boiler.
So now we need to consider how to modulate the boiler power output.
Many modern gas boiler designs can and do modulate their power output over quite wide ranges — as much as 10 to 1 — while under continuous fire, but with varying firing rates and corresponding air flow rates and, at the same time, maintain decent efficiency. With intelligent design it is not particularly difficult to manage boiler input and return temperatures at values which best suit the boiler, while maintaining the circulating temperature as desired.
Thus a modulating gas fired boiler will only be producing more power output than the system requires at very low power requirements — although even there there may be advantages in using a buffer tank.
The real need shows up with oil fired boilers, which are remarkably difficult make with a modulated power output: they are either on or off (note that his commentary is dealing only with residential and smaller commercial boilers, and is not applicable to larger, especially power, boilers, which can and do modulate).
If you cannot reduce the steady firing rate and hence power output of the boiler, the only other way to match the power output to the load is to turn the boiler on and off, with the duty cycle such as to match the average power output over time to the demand. Thus, for example, if the power output of the boiler is 100,000 BTUh, but the demand is only let's say 75,000 BTUh, you would run a 75% on duty cycle — which could mean anything from 90 seconds on in 120 minute cycle to 45 minutes on in a one hour cycle.
The function of a buffer tank is simply to provide water hot enough for the system use during the times when the boiler is off. The tank size will determine two things: first, the variation in water temperature available to the system as the boiler cycles on and off (which, using a thermal mixing valve, can be reduced to zero or nearly so provided the buffer tank water is always hotter than the desired system temperature) and second, relatedly, the total length of one cycle — with a larger buffer tank allowing both longer cycles and more even temperatures.
Now longer cycles are desirable (or very very short cycles, but that's another and more complex topic) as they allow the boiler to operate more efficiently, as well as causing somewhat less wear on the boiler components.
It must be added that the thermal inertia of the emitters is also a factor which enters into the judgement as to how big a buffer tank is optimal for the job.
Unfortunately, I do not know of any "rules of thumb" which are generally applicable, although Caleffi through its Idronics research and publications, has done a great deal to fill this gap; there are many variables which must be considered, some of which are related to the overall system, some related to the variation in power required, and some simply related to economics.
As a general thing, however, it is my opinion that for an oil fired hot water system, or a non-modulating gas fired system, a buffer tank is a required part of a competent design.
