I've got several gate valves on my central heating system around the hot water cylinder. One of them, leading to a towel rail, leaks when turned fully on or off. As air bleeds out first, and as I've been having trouble with air in the system generally, could this be the source? Could I fix it by putting some sealant around the spindle - the leak seems to be around where it enters the valve body?
Leaking gate valve
- Thread starter pict
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B
breezer
surely if you have to fix the valve, may as well change it?
Hi Brumylad! How do you propose 'pict' can fix his valve? I don't think sealant will achieve the desired result. Do you know if packing for the gland can be purchased. I think tallowed hemp might cure it?
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pict,
If the pump is before the cold feed/expansion pipes (the neutral point), such that most of the system is under negative pressure when the pump is running, then the valve could suck in air (and leak water when the pump is not running). However, if the system is under positive pressure (the pump after the neutral point) then the valve is unlikely to be the source of air in the system.
Is the problem gas in your system definitely air? Corrosion within the system produces hydrogen gas. A water leak causes fresh oxygenated water to be introduced into the system. This not only accelerates the corrosion but also dilutes any corrosion inhibitor.
Gate valves are relatively cheap, so, as breezer said, it would be best to just replace it (rather than try to fix it with sealant).
If the pump is before the cold feed/expansion pipes (the neutral point), such that most of the system is under negative pressure when the pump is running, then the valve could suck in air (and leak water when the pump is not running). However, if the system is under positive pressure (the pump after the neutral point) then the valve is unlikely to be the source of air in the system.
Is the problem gas in your system definitely air? Corrosion within the system produces hydrogen gas. A water leak causes fresh oxygenated water to be introduced into the system. This not only accelerates the corrosion but also dilutes any corrosion inhibitor.
Gate valves are relatively cheap, so, as breezer said, it would be best to just replace it (rather than try to fix it with sealant).
A gate valve has a gland nut like a stoptap. Could it not be turned shut all the way and undo the gland and push some packing in such as ptfe tape or strands of wool.
Would be better to renew though if you are confident
Would be better to renew though if you are confident
MANDATE said:Hi Brumylad! How do you propose 'pict' can fix his valve? I don't think sealant will achieve the desired result. Do you know if packing for the gland can be purchased. I think tallowed hemp might cure it?
Use of Tallowed hemp is avoided in potable water installations because it can support the growth of micro-organisms.
Like Bacho suggests PTFE tape might be more appropriate.
This valve is clearly (?) NOT on the potable-water part of the system, so whatever works as gland-packing, use it. That said - there's not much wrong with PTFE tape...
Who is this Bacho
The next one that gets my username wrong gets a prize
The next one that gets my username wrong gets a prize
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