Comparing Sealing Methods for Threaded Connections in Gas Installations

Question

Hello, I intend to replace the damaged gas valve next to the stove in the near future. So I have a question about sealing threaded connections - namely which solution do you think provides the best ? connection? best: - the most sealed, - resistant to temperature changes, - non-corrosive, -...

brofran · Accepted Answer

That I would absolutely not recommend.

jareckim · Accepted Answer

I use Teflon tape in such cases. Connections tested with a gas detector and zero leakage.

misiek1111 · Accepted Answer

If it is to be: it will fulfill them: (or another tow paste). The connection must be made correctly, that is: - mechanically clean both threads, eg with a wire brush, - external thread should be cut so that the tow does not slip during turning, - apply the paste to the external thread, - slightly twisted tow roll up tightly to the thread, - put on tow paste, - turn the valve, - perform installation tightness measurement. After twisting, the tow crushes and mixes with the paste, which creates mush, with the consistency of plasticine. The paste fills the pipe gaps, limits the oxygen supply from the air, works together with the pipe (deforms thermally), does not combine with metals and does not change after years, so you can combine it as easily as possible (my few water connections at home I have from 1/4 of the century and were opened up by me).

jareckim · Accepted Answer

I used Ferro valves Although I do not shoot it too often, maybe three times from the moment of installation, but it does my job. Opens and closes the gas supply.

dobroslaw · Accepted Answer

Threads are enough to scrape with a blade, if you want connections, I always recommend tow and linseed, if propane gas is only Teflon or Teflon thread, I use only teflon thread because even when you take it back you do not have to scroll and never let it go.
One more rule, whether for water or gas valves, valves consist of 2 parts so as to put inside the ball, some solid give you pressure, and screwed on the other side, I do not know how in gas because I did not meet but on the water sometimes wasted the valve breaks at the connection and pulls it under pressure, and when you give a solid part, you can close the leakage despite the damage. In the photo shared by you, a part of the lit is the right to the left network of the device.

jareckim · Accepted Answer

Both valves are of the same class and quality. One remark when connecting steel pipes with elements made of brass. It must be remembered that brass is less durable and when used as sealing, the tow can be over-bent and the wound is too thickly wound, which can cause the brass valve to break when screwed. A safer seal is the use of a Teflon tape.

Zbigniew Rusek · Accepted Answer

Multipak paste (Unipak is more like water) or GB-1. In the past, when there was no paste, the tow was impregnated with a face (I do not recommend it - especially with a varnish, because it can not be unscrewed afterwards) or with a coil (if it is a real TOTOT, not another grease, it was good for water or gas - I can not guarantee). As for the Teflon tape, it is often the producers of stoves and stoves who rely on it. It ensures tightness, but on the condition that after screwing it will no longer screw in the thread (eg loose), therefore I do not rely on sealing eg eccentrics with wall batteries (because you sometimes have to adjust the setting, and this may unseal). Which way to install the valve - on the valve body should be an arrow showing the direction of flow.

misiek1111 · Accepted Answer

Once in the first century. The order -> pipe, ball valve, filter, stove.

Zbigniew Rusek · Accepted Answer

Generally, they are the same. There is one thing - brass fittings are recommended for the water, because the steel, in combination with moisture, corrodes (but it is commonly made of steel). When buying, for example, ball valves, you need to pay attention to be adapted to gas (in the case of valves is important) - those for gas always have a yellow handle. As for the soldered installation, the gas can only be combined with HARDNESS (ie with a relatively high melting point).

dobroslaw · Accepted Answer

Avoid zinc, for black-and-white hot dip, black shapes are forbidden, for CWU you can give copper, brass, pex, because the zinc also overgrows and after a few years the diameter is reduced by half, (once this galvanized was better)

http://www.a-test-serwis.pl/strony/14/ocynk-zabroniony/

For hard gas solder, black seamless tubes and black fittings, with Teflon sealed propane, natural gas can be towed or Teflon

Maciek0468 · Answer

Ok thank you for help. You helped me make the decision, finally I ordered Multipak paste and linen tow.
@ misiek1111 thanks for a detailed description of what and in what order to do - very helpful.

I still have a question about the previously mentioned gas (ball) valve. The one that I plan to replace, can be turned at will and will not turn it around. It is sealed, but what if it does not fulfill its basic role. I can turn the handle 360 °, and gas how it flew so flies. Can you recommend a company that produces decent valves? Only in reason, because I would not like to spend 200 zlotys on a stupid valve, although I know that it is not stupid and it plays a very important role in the installation. Thanks

BTW. I heard that Multipak pastes are good sealants for gas installations, and are there any better?

Maciek0468 · Answer

Thanks, and you know something about Valvex products? I made a small comparison and it seems to be OK, but I prefer to ask professionals and people who know / have permission to do so (page 232)

Maciek0468 · Answer

Hey, thank you for the answer. @dobroslaw - honestly, I have never heard of this dependence in which direction to install the valve, but it makes sense and from then I will stick to it - thanks. If I have understood everything correctly, the following figure illustrates the correct assembly method. It's about natural gas installations, in a block. I am interested in this categorical ban on using them with cylinders, i.e. propane-butane. It is known that tow tend to swell when they get water, which is why they are discouraged in PVC and polymer installations. I also know that they can rot against what they protect it with. Somewhere, I read that in cylinders there is high pressure (about 6 atm), which is of key importance while maintaining tightness. And this seal can only be guaranteed by Teflon. Therefore, tow is advised against, while the chemical compound itself is of little importance. I wonder how it really is? In order to be clear, I am not an opponent of Teflon, but I will use tow with paste to do the above. I will leave Teflon for special applications

Maciek0468 · Answer

Hey, thank you all for your help.
Your advice is valuable to me, so I can handle one more thing. It is about using a gas slant filter.
I think that since I am already doing this job, it's worth doing it the best. So I invented installing this filter.
The outlay is small, and I prefer to be sure that the gas that reaches the oven is free of impurities. In addition, it is easier to clean the filter than the stove, or even worse to look for a defect in the oven caused by contaminated gas.

And now I think in which place it (the filter) mount in front of the ball valve or behind it. I have the "main" gas valve right after the entrance to the apartment (brass conical valve), but I read that it should not be used too often, because it can be unsealed - how much I do not know. I could mount the filter right behind it, and as the next and last element I would give a ball valve that would already work in clean and filtered gas - which would also be irrelevant to it). But I do not want to strain this damn most important conical valve. Somehow I do not see myself putting on two ball valves one before the filter and the other behind, it does not make sense. The obvious thing is that I need to turn off the gas to clean the filter. Probably I will not do it more often than once, maybe twice a year (by the way how often it should be cleaned), but considering the fact that I have not used a conical valve for the last 10 years, this is some exploitation for him. That's why I ask you how you would do it and how it is according to art?

Below is a pictorial picture

jareckim · Answer

The main valve has nothing to move. It's a gas valve. The gas plant takes care of the gas purity. The filter is probably in front of the central gas meter. If you want to set up your filter, just after the ball valve and possibly check its purity once every 15-20 years. And it's provided you use the oven very often.

Maciek0468 · Answer

Thank you for your help. The last question I have regarding fittings, nipples, screw connections, etc. Is there any special group of these products dedicated to gas installations, can I use materials used, for example, in hydraulics?

jareckim · Answer

Steel galvanized. It does not seem to produce any plastics before. Galvanized pipes and fittings withstand 25-30 years in water installations. In gas installations ages.

geno60 · Answer

Hello Where can I find provisions prohibiting the use of tow on threaded connections in a propane gas installation? Regards, Geno

Comparing Sealing Methods for Threaded Connections in Gas Installations

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