Old-Style Radiator Valve Leakage Repair: Fixing Cast Iron Radiator Valves, Replacing Gaskets/Heads

Hello and welcome. I have old, reliable cast iron radiators and also old but less reliable radiator valves (those with these black knobs). When they are unscrewed, everything is ok, but when you try to turn them, they start to leak. Is it possible to repair these valves by e.g. replacing gaskets / heads, etc.? Thanks in advance.

Hello, the reason for the leakage of these valves is the manufacture of the valve stem seal, you can easily replace the seal or try to tighten the screw tightening the seal. You need to unscrew the screw that secures the bakelite knob, on the axis (under the knob) there is a screw tightening the seal, you can tighten it until the leak stops, if after tightening the water is still leaking, you need to replace the seal. You have to unscrew this screw completely and take out the old packing (ordinary tow) and re-wind a few coils of new tow, and then tighten the set screw. After such an operation, the valve should function well.

It seems to me that it would be easier to buy a new one, it is not a fortune, about PLN 15 regeneration of these monuments is not very profitable, looking for gaskets, winding up with hemp is a waste of time and you still have to drain the water from the installation.

Thanks a lot. I'll try to seal it. I don't have to drain all the water, just to below the level, right?

krzysio_sr wrote:

Unscrew the valve as far as it will go and do.
This is done under pressure (don't be scared - it's a completely safe job)

Hello!
Do as "krzysio sr" advises, only place the vessel so that the water is dripping down.

łe - it's a fairy tale. I'm just gonna buy a rope in grease and have some fun.

Hello!
If you have difficulties with buying, let me send you the contact information.

Gentlemen, what is the price of such a rope?

Hello!
I wrote that I would send you a stamp that I can still afford and the cord is free of charge.

12gucio read carefully, Question -The answer is how it works.

I guess it's hard to get hold of. You will pay for everything with the Mast card ....., and the rope is free from 12gucio.
If I look for it well, it will be with me too

mirrzo wrote:

I guess it's hard to get hold of. You will pay for everything with the Mast card ....., and the rope is free from 12gucio.
If I look for it well, it will be with me too

I found a replacement, a Teflon tape, but the one on large yellow rolls for PLN 5. Operation similar to the original. It does not rot like the original.

Hello,
I also have such old type packing valves. Not all of them are repairable and replacement is not easy. Such valves are not on sale, but I found something like this:

http://www.ceneo.pl/8291581

I have a question: is it possible to use the "guts", i.e. the mushroom, gaskets and stem of a new cast iron valve and install it in the old gland valve housing after removing the old knob and gland? Will these items be up to
fit each other?
This would make the replacement easier, because I wouldn't have to touch these fittings on the pipes, move the radiators, etc.

Well, unfortunately it will not be as good as a colleague came up with. The radiator valve is of the mushroom type but with a brass plug of the sphere segment type. The one on offer is a mushroom with a soft seal. So that it can and can be replaced, but it will not function. Such a knob in the apartment is also not a decoration. Replacing the insert requires draining the system.
Meanwhile, replacing or refilling the sealant doesn't have to be difficult.

mczapski wrote:

Well, unfortunately it will not be as good as a colleague came up with. The radiator valve is of the mushroom type but with a brass plug of the sphere segment type. The one on offer is a mushroom with a soft seal. So that it can and can be replaced, but it will not function. Such a knob in the apartment is also not a decoration. Replacing the insert requires draining the system.
Meanwhile, replacing or refilling the sealant doesn't have to be difficult.

Thank you for the answer, this is the information I meant.
So, as I understand it, the new spindle is due to a different structure, even if it can be placed in the old housing, it will not fit into the old structure enough to e.g. stop the water flow to the radiator completely?

He doesn't care so much about aesthetics, it's more about a valve that won't dampen the flow, which is what most new type of radiator valves do, which have a lot of constrictions and block gravity. When I watched this KFA, it seemed to have quite a lot of flow, just like the brass gate valve. Anyway, KFA in large sizes can be found directly at the boilers.

The stuffing box valves were repaired, but not all of them could be repaired, because not always the problem was only in the stuffing box hemp.

dgolf wrote:

łe - it's a fairy tale. I'm just gonna buy a rope in grease and have some fun.

If there is no asbestos string (you used to seal it this way), then you use tow heavily soaked with grease (necessarily with a thread) or - preferably - with a good thread paste. You need to make a string from the tow and saturate it with a sealant.

Zbigniew Rusek wrote:

If there is no asbestos cord (it was used to seal it like that),

Unfortunately, no, because it was tallow rope, sometimes graphite.

Hello. I have the same valve as in the picture above. It is also leaking ... I would like to replace and buy a butterfly water valve ... You will help what it should be exactly. Of course with a return valve. I don't know about it ... Whether it's supposed to be a nipple or a flare. The tube is 3/4 inch.

Hello, you need a 'water valve 3/4 "with a screw connection and a throttle, butterfly'

OK thanks

Unfortunately, I deal with ball valves and there are problems with them, despite the use of different companies, even the version with a throttle, they leak quite easily, especially with hot water and radiators.
I do not know if there is a better alternative, but in one radiator I have valves with heads (from the outside they are similar to ordinary heads) and nothing is happening with that, the rest are ball and a few have already been mentioned.
Maybe it was just bad luck that it was crap.

I have a question, where is this packing cord installed? As you can see in the photo, there is a rubber O-ring in my gland, but the valve is dripping slightly so I have to seal it somehow. Does this cord replace this black O-ring? Should a packing cord also be attached to the thread of this hold-down nut?

If there is an O-ring, no rope is given, no tow. You need to inspect this o-ring and, if it is worn (even if it is minor), replace it with a new one, and check the inside of the valve for any scale or sand, as such contamination can cause bad sealing by the o-ring. Maybe this O-ring is too thin.

Zbigniew Rusek wrote:

If there is an O-ring, you don't get any rope, tow. You need to inspect this o-ring and if it is worn (even if it is minor), replace it with a new one, and check the inside of the valve for any scale or sand, as such contamination can cause bad sealing by the o-ring. Maybe this O-ring is too thin.

I took out the o-ring and it is not damaged anywhere. I will ask if there is a leak from this type of valve due to a cause other than this O-ring? I am asking because I have the impression that the water slowly comes out from the very top of the head, i.e. from the area of the square spindle on which the knob is placed.

You probably have a good impression. The o-ring on the thread only seals the threaded joint. Now you have to get to the valve spindle, i.e. probably remove the protection from the spindle and only check the seal. I can't deal with the photos in detail, and I don't think I have such valves at hand.

It looks a bit that the part on the side of the knob is a gland sleeve. So it would be unscrewed like in many valves. There is a sealing material under the sleeve (surely some rope).

Bałdyzer wrote:

I took out the o-ring and it is not damaged anywhere. I will ask if there is a leak from this type of valve due to a cause other than this O-ring? I am asking because I have the impression that the water slowly comes out from the very top of the head, i.e. from the area of the square spindle on which the knob is placed.

If at this point (from the spindle axis), the reason is the throttle (these leaks are quite common, especially when you turn these valves). Normally there should be one more nut holding the gland in place, but the photo does not show the gland at all (no photo with square tip end view). If there was a gland, the O-ring would also be inside (with frequent spinning, it would wear out) and the repair would consist in replacing it (sometimes you would stuff an asbestos string / tow saturated with tow or thread paste and tighten the nut). This valve is strange - it does not look like a radiator valve at all, or something unusual.

I drained some water from the installation and took the head out of the valve. In the photo, I marked the place where the water is leaking with an arrow. Can any of you tell me how to disassemble such an old head to somehow seal it inside?


For now, I bought a plug with a M30 x 1.5 thread and blocked the valve so that there was no leakage

This is not a typical head of an old radiator valve, where the seal (gland) is tightened with a cap nut. It looks to me similar (in terms of the spindle structure) to those of the bath / washbasin / sink faucets from the so-called stationary spindle. Theoretically, it can be dismantled - it has to twist the spindle so that the entire spindle goes beyond the head from the back. There is definitely an O-ring on the spindle axis and it is probably worn (from temperature control, and this is a radiator, so the valve was hot, which causes faster wear of the rubber) and it needs to be replaced, and then the valve assembled. I would suggest replacing the entire valve (with a thermostatic head). Attention. The head should be placed horizontally (if it is thermostatic) and not vertically above the supply pipe, as vertical placement (upwards, i.e. directed over the supply pipe) will distort the interpretation of the temperature, as the heat from the hot pipe will heat the head) - from two bad points it is better give it vertically, but downwards, and preferably horizontally - the latter is the correct assembly. Of course, this requires draining the water from the installation (at least as much so that there is no water on a given floor).