What is This Plumbing Item?

The cross in the centre makes it sound like a vortex breaker.

I have since removed it from the tank. It appears to be a plastic isolation piece, firmly attached to the inside of a special steel male nipple which is screwed into the tank's projecting female nipple, with a 3/4" od x 32" solid sacrificial anode firmly attached to the plastic piece.

The plastic piece has a horizontal tunnel above the anode(?) that allows the hot water to enter and travel upwards thru the plastic piece. The cross I referred to earlier is actually just an integral plastic bar.

So right now I'm concluding its just an easy, economical way to install an isolated anode.

Does it look like this?

3/4 in. x 3/4 in. Steel and Plastic MNPT x MNPT Dielectric Water Heater Heat Trap features inert thermoplastic linings to help prevent lime and scale buildup.

- Helps prevents galvanic local cell corrosion
- Steel construction with inert thermoplastic lining to help prevent lime and scale buildup

Good morning Iris,

No, I have since removed it. It is a neat invention to allow the insertion of an isolated anode in the same nipple the hot water exits the tank, without having to weld on a nipple just for the anode.

I saw some down at the hardware store this am.

Hi Flyinghigh,

it could be a pressure relief valve. try to google if it looks the same. usually most of the domestic hot water tank fitted with pressure relief valve and air breaker/release. However as what the nearest guess as you said "has a cross in the center" could be the pressure relief valve".

You should asked the hardware when you saw it this morning as you said.

Roman