by bill wuttke
(wisbech cambs england)
Hi, when i open the water drain on my 150l tank it does not always rush with air/water can i remove the whole valve without it leaking bill.

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Howdy, Bill.
You say that when you open the tank drain valve that water doesn’t always rush out. Is there water to rush out?
Certainly, if the tank has air in it, when you open the drain valve, compressed air should blow out the drain valve, and carry any water there along with it.
Can you remove the drain valve without it leaking? Does this mean that you might damage it when you remove it? I’m not quite sure what you mean by “without it leaking”?
The tank drain valve is normally threaded into a tank fitting, and powerful sealant is often used to help ensure that the threads don’t leak. So, it is possible that you will damage the drain during removal though I’ve heard of some success with folks removing seized threads by applying heat from a torch.
Replacing the tank drain valve is pretty easy if the old one is out and the threads are not damaged.
One thing that might be useful instead of just adding a drain as shown above, but to thread an elbow into where the tank drain used to be, add some tube so that it extends to the side of the tank, and add a shut off valve there. Then draining your tank becomes very easy.