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charles tuit · 08-12-2017, 06:35 AM

Just installed a new water pump and water pipes are vibrating. I wanted to isolate the pipes downstream by cutting the pex pipe and installing a short length on coiled hose. I searched for pex compression fitting with hose barbs for 1/2" hose. No luck.

Does anyone have a different idea to eliminate the hammering/banging of pipes when pump is running. I have no problem when on city water.

Winemaker2 · 08-12-2017, 06:56 AM

Quote:

Originally Posted by charles tuit

Just installed a new water pump and water pipes are vibrating. I wanted to isolate the pipes downstream by cutting the pex pipe and installing a short length on coiled hose. I searched for pex compression fitting with hose barbs for 1/2" hose. No luck.

Does anyone have a different idea to eliminate the hammering/banging of pipes when pump is running. I have no problem when on city water.

You are on the right track
Worst case use pex to NPT then NPT to hose Barb.

Waiter21 · 08-12-2017, 07:05 AM

The "Shark teeth" style fittings should be available at any big box store. These simply push onto the tube, install a locking ring, and you should be good. You might find these fittings that you can screw a barb into.

ALSO - Try this. Turn the water pump off and disconnect from city water. Open the pressure release valve on your water heater, then remove the drain plug on the water heater to allow a quart or so of water to drain out. Snug the drain plug back up and close the pressure relief valve..

This will suck air into the water heater and there will now be a small air pocket trapped in the top of the water heater. This small air pocket may be enough to stop the water hammer.

Old Crows · 08-12-2017, 07:17 AM

You are doing it the hard way.....

You want this. Pump Silencing Kit | Pump Silencing Kit

Isolates the pump from pipes. Softer material.damps the pulses before the water system

l1v3fr33ord1 · 08-12-2017, 07:20 AM

Charlie-

Crimp on of these on the PEX:

SharkBite 1/2 in. Brass PEX Barb x Male Pipe Thread Adapter-UC120LFA - The Home Depot

and then use one of these to connect the water pump and the above fitting:

BrassCraft 1/2 in. FIP x 1/2 in. FIP x 20 in. Braided Polymer Faucet Connector-B8-20A F - The Home Depot

Not all HD retail stores have them, but the above hoses come in 12-, 16-, 20-, 24- and 30-inch lengths. I use ones long enough to put a loop or partial loop in the hose, which helps reduce the stress on the end fittings. Make sure you get the FIP-FIP (Female Iron Pipe) hoses, not the ones for compression fittings. The hoses have a washer inside that will snug up against the brass fitting, so hand-tighten; you shouldn't need any pipe tape.

I use these on my coach and it's the cat's meow. Very little noise transmitted from the pump.

If you have hammering or pressure fluctuations, rather than just noise transmission, more investigation will be required. What pump make/model did you replace, and with what make/model did you replace it? Do you have an accumulator in your system?

ThePowells · 08-12-2017, 09:13 AM

I had that on mine that was a loud rhythmic thunking clunk and you could see them moving when on the pump. I removed the filter and drained the canister and then replaced it. Most of the noise went away and it is almost back to the original level, but I also had one of those flexible hoses that was bent and collapsed when the slide was closed. Correcting that also helped. I have a good spot for an accumulator tank when I upgrade our pump.

hohenwald48 · 08-12-2017, 10:51 AM

One of these helps a lot.

https://www.amazon.com/Seaflo-SEAFLO...expansion+tank

They come in different sizes. Use the largest you have room for.

l1v3fr33ord1 · 08-12-2017, 11:30 AM

A couple of notes on accumulators:

1) Some pumps (e.g., the variable-speed type) are designed to not need an accumulator. The manufacturer's installation instructions will spell this out.

2) Accumulators can provide expansion space for hot water heating. This is a primary function in house ("stick and brick") plumbing. In an RV, the expansion capability is in addition to that provided by the air "pocket" at the top of the water heater. In any case, you can use an on-line calculator such as this one, to size the accumulator for hot water expansion purposes. For my coach, I needed a one liter tank pressurized to 40 psi. Here is a link to the model I purchased.

charles tuit · 08-12-2017, 01:02 PM

Problem solved.

With a little advise from all I went to pex NPT compression fitting. I then attached a braided faucet connector (does't kink like water hose). Quiet as a mouse.

Thanks again to all who responded.