Extra long copper pipes

[Daniellec78]

Hi, my copper pipes for the vanity are very long and I want to cut them so the valves end up below the shelf. Is there a reason for them being so tall? Any reason not to cut them down?

Danielle

 

[Reach4]

I think they were made tall to let you cut them to the height that you want.

 

[Sponsor]

 

[Cacher_Chick]

I would cut them so the valves are ABOVE the shelf and notch the shelf to fit around the pipes. It is no fun reaching down under a shelf to get at the valves when you need to.

 

[Gary Swart]

And if you cut them too short, you would had a shortage of water. Not. Sorry for a poor joke. For real, if you are concerned about appearance of the valves, consider 1/4 turn valves that are meant to be visible. These are often used for toilet supply, but will work anywhere.

 

[Themp]

The long length I think was done to stop water hammer. i.e. the section above the current valves. But current thinking is that these sections fill with water over time and thus become ineffective. I have these all over my house and I used to drain the system to try and get air back into the extensions. But someone commented here that the extensions can hold water like when you put your finger over a straw. Just replaced my shower valve and got rid of the two here.

 

[Flapper]

They are long so you cut them to the length you want.

 

[Cool Blue Harley]

It used to be thought that an air chamber, or capped stand pipe, was a effective solution to controlling water hammer. However, within an air chamber, nothing separated the air from the water. It only takes a few short weeks before the air is absorbed into the water, leaving the air chamber waterlogged and completely ineffective against water hammer.

They are commonly required in many jurisdictions.

The most effective means of controlling water hammer is a measured, compressible cushioning of air which is permanently separated from the water system. A manufacturer water hammer arrestor.

Air chambers are 24 times the pipe diameter. Your half inch pipe, in your photo, has 12 inch air chambers.

 

[hj]

could you have gotten any farther away for the picture? It is impossible to tell anything other than that they are very tall. Are there tees and valves above the floor?

 

[Reach4]

could you have gotten any farther away for the picture? It is impossible to tell anything other than that they are very tall. Are there tees and valves above the floor?

Ahh... I had missed the valves, which I now see. Good eye themp.

I think a bathroom lavatory does not usually need water hammer arrestors, because the valves do not turn off fast. So you could just cut those down and cap rather than putting in the more modern arrestors.