Still more plumbing... water heater inlet pressure relief valve?

[HeavyDuty]

Now that I installed a pressure regulator and the house water pressure is a manageable 45 psi, I need to deal with a broken gate valve on the water heater supply line. I’m trying to figure out why mine has a separate pressure relief valve on the inlet side in addition to the usual T&P valve on the water heater body. (It’s a higher efficiency LP 40 gallon.)

Has anyone seen this before? I’d like to slam in a Sharkbite combination ball shutoff valve and flex connector, and retaining a PRV in that area is more involved.

66865

[whomever]

Dumb question maybe ... is that a pressure relief valve or an air admittance valve?

[HeavyDuty]

Good question. I have no idea.

[whomever]

I can't tell from blowing the picture up ... any markings that google might identify?

[NH Shooter]

It's a vacuum relief valve, so you should either keep it or replace it with this - https://www.amazon.com/Watts-3-4LFN36-M2-0556031/dp/B007VHIEMG/ref=pd_bxgy_img_2/140-0700162-2607715?_encoding=UTF8&pd_rd_i=B007VHIEMG&pd_rd_r=e08a3d5c-9de3-4bd4-aaab-97e56f6c50ed&pd_rd_w=zTFIL&pd_rd_wg=JMSbc&pf_rd_p=f325d01c-4658-4593-be83-3e12ca663f0e&pf_rd_r=G3K4BXKXP0ZQVQ16NM84&psc=1&refRID=G3K4BXKXP0ZQVQ16NM84

Gate valves suck on water service - replace it with a ball valve.

Feel free to reach out to me if you need more help (I'm the product manager at Watts for these products).

[HeavyDuty]

It's a vacuum relief valve, so you should either keep it or replace it with this - https://www.amazon.com/Watts-3-4LFN36-M2-0556031/dp/B007VHIEMG/ref=pd_bxgy_img_2/140-0700162-2607715?_encoding=UTF8&pd_rd_i=B007VHIEMG&pd_rd_r=e08a3d5c-9de3-4bd4-aaab-97e56f6c50ed&pd_rd_w=zTFIL&pd_rd_wg=JMSbc&pf_rd_p=f325d01c-4658-4593-be83-3e12ca663f0e&pf_rd_r=G3K4BXKXP0ZQVQ16NM84&psc=1&refRID=G3K4BXKXP0ZQVQ16NM84

Gate valves suck on water service - replace it with a ball valve.

Feel free to reach out to me if you need more help (I'm the product manager at Watts for these products).

Thanks for confirming that it’s needed - I’ll figure out how to incorporate the one you linked in the new setup. And yes gate valves suck, hard.

[tadawson]

Question: Why do you say gate valves suck? They are far less restrictive than a ball valve . . .

[Sharkbite]

"Why do Gate valves suck..."

Let me count the ways.
Sediment can build up in the recess that the gate seats down in and not shut off the water flow completely.
The gate can seize in position.
The stem can break free of the aforementioned seized gate.
The packing can leak, even after tightening the packing nut.
The handle can come apart in your hand while applying force to the above.

They are terrific for metering water on equipment, but that is about it.

Also Ball valves that are full port are the same diameter as the I.D. of the pipe.

Trust me, I'm a commercial Plumber.

P.S.: The the vacuum breaker is missing the plastic hat, so that is why it was harder to identify.

[HeavyDuty]

The stem can break free of the aforementioned seized gate.

... which is what happened here.