Help Identify this drain/vent line

[lsvteceg692]

I own a Pulte built townhome and on the rear of the unit is the attached drain/vent line. On the left side it has a threaded adjustment. The thing constantly is dripping. Trying to figure out what this is and if it is adding to the water usage.

This is not the Ac condensation line as this is located in a different area.

Any help would be appriciated!

Thanks

Zach

[Sylvan Tieger]

The device is a cold water pressure relief valve where some one installed a ferrous metal nipple and cap on a non ferrous metal valve defeating its purpose and cauing a classic electrolitic action ..

For your information there is no ajustment on safety devices ( check out the ASME, NBBI,AGA, NFPA)

One has to love the non licensed plumbers dabbling on the unknown.. who ever installed the nipple and cap you should check what other safety devices they tampered with

[lsvteceg692]

What is the need for a cold water relief valve and what is it hooked up to?

I understand a HOT water relief value....but cold?!?!?!?!?

Thanks

[Sylvan Tieger]

Where there is a possibility of excessive pressure (over 125 # normally) then to protect the system a pressure relief is installed even on cold water..