Seized stopcock

[Observer]

I have a seized 22mm stopcock (stuck in open position) on the HW feed from a Megaflo cylinder to a bathroom. After trying (and failing) to shift it myself, it started leaking from the gland nut, so I called on my home emergency cover to get some professional help to see if a pro could (a) stop the leak and (b) get the valve moving. He fixed the leak (in about 10 seconds) and I asked him to try and get the valve moving. I think he did try but not sure how hard as he may have been worried about it breaking. Anyway, it's still solid.

He suggested I should replace the entire valve with a quarter turn lever one and replace the two others alongside at the same time. That's certainly possible but likely will be quite expensive and it's not really necessary to replace the other two as they are moving freely.

Is it worth trying to crack the valve body and replace it with one taken same from a new one? What are the chances of a new one having exactly the same thread?

TIA

 

[JohnD]

please show us a photo of this stopcock.

 

[HERTS P&D]

Fit one of these:

https://www.screwfix.com/p/pegler-ball-valve-red-22mm/45277

Andy

 

[oldbuffer]

1. If it has a red circular disc as a handle, it is a gate valve, not a stop cock.
2. They frequently stick, and can actually snap (internally, no water spurting out).
3. Particularly prone to failing to close fully if the inlet and outlet are horizontal as muck gets lodged in the seat so they can't close fully. Better mounted vertically.
4. A decent quarter turn valve (e.g. Screwfix 18343) is around £10 to £12.
4a. If gate valve and lever valve require same size gap in the pipe, an easy fix. Turn off the cold to the Megaflo, run off any hot remaining in the pipes (bathroom tap, don't use a tap too far below the cylinder), undo the gate vale and fit the lever valve using old nuts and olives still on pipe.
4b. If different size will need some pipework alterations.
5. The only advantage I can see for a gate valve over a lever valve is that the gate valve provides fine adjustment over the flow, which is a bit more difficult with a lever valve.

 

[Observer]

please show us a photo of this stopcock.

Here's a pic. The seized one is on the left. The centre one was leaking some time ago but just needed the gland nut to be nipped up.

If I decided to replace all three with lever valves, would they all open and close independently without clashing?

 

[HERTS P&D]

Direct replacement:

https://www.screwfix.com/p/stopcock-22mm/51569

Andy

 

[BlueLoo]

Buy a pipe freezing kit, and remove the gland, clean it up, and refit.
Less fuss less costs?

Or drain down and do same.

No need to remove the valve body.

However, having new washers, etc on hand should the old ones be perished might be an idea.

 

[JohnD]

if you support the body of the tap with giant stilsons (to avoid putting any twisting force on the pipe) I think you will be able to undo the large nut and take out the headworks. Once you have them on the bench or in a vice I bet you can take the valve apart. Use spanners of the exact size, as brass is easily damaged and rounded off.

If going to the trouble of repair, I like to polish up the parts with wire wool or green scourer and lubricate with a tiny smear of white plumbing silicone grease. Where parts screw into each other and need to be sealed (e.g. where the headworks screw into the body) you can put a few turns of white PTFE tape on the thread and push it into the grooves with your fingers to prevent it scraping off on reassembly. This will also seal against water leaks and prevent it seizing again. There is a good chance you can find an identical valve, especially if there is a makers name or initials anywhere.

Once you have done one, you can do the others, including the one that has a leak, probably on the spindle gland stuffing, where, again, you can use PTFE tape. In most cases, PTFE is not used on screw threads, as they do not usually form the seal (e.g. compression joints, where the olive is the seal).

BTW valves should never be screwed hard out against the stop, or they will seize. Open, then back off a quarter turn or so. Should last about 80 years.

p.s.
good idea to start by undoing the gland nut, give it a try, though this may not free the seized part.

 

[Observer]

if you support the body of the tap with giant stilsons (to avoid putting any twisting force on the pipe) I think you will be able to undo the large nut and take out the headworks. Once you have them on the bench or in a vice I bet you can take the valve apart. Use spanners of the exact size, as brass is easily damaged and rounded off.

If going to the trouble of repair, I like to polish up the parts with wire wool or green scourer and lubricate with a tiny smear of white plumbing silicone grease. Where parts screw into each other and need to be sealed (e.g. where the headworks screw into the body) you can put a few turns of white PTFE tape on the thread and push it into the grooves with your fingers to prevent it scraping off on reassembly. This will also seal against water leaks and prevent it seizing again. There is a good chance you can find an identical valve, especially if there is a makers name or initials anywhere.

Once you have done one, you can do the others, including the one that has a leak, probably on the spindle gland stuffing, where, again, you can use PTFE tape. In most cases, PTFE is not used on screw threads, as they do not usually form the seal (e.g. compression joints, where the olive is the seal).

BTW valves should never be screwed hard out against the stop, or they will seize. Open, then back off a quarter turn or so. Should last about 80 years.

p.s.
good idea to start by undoing the gland nut, give it a try, though this may not free the seized part.

Thanks for all that.

Loosening off the gland nut was tried (that's what made it leak so I could make the emergency call out!) but didn't help. I think I'll buy a replacement and experiment on what is needed to crack the body (headworks as you called it). If that seems okay, I'll drain down the top of the tank and see if I can get the body off the seized one - replace it with the new one or (possibly) clean it up and refit.

 

[Observer]

Buy a pipe freezing kit, and remove the gland, clean it up, and refit.
Less fuss less costs?

Or drain down and do same.

No need to remove the valve body.

However, having new washers, etc on hand should the old ones be perished might be an idea.

Thanks for suggestion but don't follow why I need a freezing kit. I can isolate the Megaflow and then drain down the top of the tank quite easily (I do that regularly to regenerate the air gap). Am I missing something?

BTW, the gland nut turns easily, it's the handle' that's seized.

 

[HERTS P&D]

A decent plumber could get the stopcock moving in 2 minutes.

Andy

 

[BlueLoo]

Thanks for suggestion but don't follow why I need a freezing kit. I can isolate the Megaflow and then drain down the top of the tank quite easily (I do that regularly to regenerate the air gap). Am I missing something?

BTW, the gland nut turns easily, it's the handle' that's seized.

Nope.

I don't have the benefit of looking at it directly, but the principle stands.
As Andy says above, probably not a big deal to get it moving.

 

[Schrayder]

You've just got to get it moving the first tiny little bit and you're away.

 

[BlueLoo]

You've just got to get it moving the first tiny little bit and you're away.

Just like sex....


.....wait, wrong thread....

 

[johnny2007]

Have you tried spraying penetrating lubricant for a few days?
That's how i freed mine a few years ago and it still works.