Booster Pump causing supply pipe to jerk

[AWalt]

Thanks!!

 

[AWalt]

It might make it worse as it would be further starving the pump. I would go PRV, small pressure tank, then pump.

Thanks Valveman, That makes sense. I can set the air pressure in the expansion tank and not have to worry about the water pressure fluctuation.

 

[AWalt]

I haven't installed the expansion tank yet. Here's what happens on the supply side when the Booster Pump kicks in. The resulting hammer travels all the way across the house to where my water comes into the foundation. I'll post an after video when the work is complete.
View attachment IMG_3385 (1).mov

 

[AWalt]

I finally solved my water hammer issue. I realized that the banging sound was gone after winterizing the irrigation system so it was the sprinkler line that was banging when the pump activated. My previous fix (an additional expansion tank) on the pump inlet side did not work because that line was fine. I piped in a Sioux Chief Vacu-Rester 652-AD - Sioux Chief 652-AD - Vacu-Rester Vacuum Breaker Arrester - 1/2" MIP Thread near the pump on the sprinkler line input and it worked great!! I also added the regulator on the inlet side of the pump to control any pressure spikes from the service. Grundfos MQ45 is going strong at 18 months.

 

[Valveman]

Glad you got it working and have been able to keep that MQ pump working for 18 months. Even though you have had to add some Band Aids to stop the water hammer and other problems that pump might last a few years, especially if lightly used. But I predict it will need to be replaced many times in the next 30 years or so, where you would only need one regular jet pump to last that long.

 

[AWalt]

I'm sure you're right. Which pump would you recommend I get when this one goes? How large a storage tank?

 

[Valveman]

I'm sure you're right. Which pump would you recommend I get when this one goes? How large a storage tank?

Since the MQ3-45 is a 1HP I would recommend a Goulds J10S pump with a PK1A control kit using the 4.5 gallon size pressure tank.

 

[AWalt]

Thanks Valveman! Will that work as just a pressure booster? I'm on city water.

 

[Valveman]

Thanks Valveman! Will that work as just a pressure booster? I'm on city water.

Yes it will. Just need a check valve on the city line prior to the pump.

 

[AWalt]

Great!! Thank you. That set up will be just a little bit more than what I paid for the MQ-45. I wish I had known. I really appreciate your help.

 

[Twowaxhack]

Make sure you address thermal expansion if you have a tank water heater.

 

[AWalt]

Thanks Twowaxhack. I changed out the Water Heater last year with an AO Smith. I put in an expansion tank and Taco leak detector w/auto shout off valve.

 

[Valveman]

The tank on the PK1A will take care of thermal expansion just like any water well pressure tank. Just don't put any check valves after the pump and PK1A.

 

[Twowaxhack]

The tank on the PK1A will take care of thermal expansion just like any water well pressure tank. Just don't put any check valves after the pump and PK1A.

Depends on how big his water heater or heaters are and how hot he sets the temp.

With and with your cycle valve you usually recommend a 4.5 gal tank.

 

[Valveman]

Depends on how big his water heater or heaters are and how hot he sets the temp.

With and with your cycle valve you usually recommend a 4.5 gal tank.

I may stand corrected? But I have never seen a residential expansion tank larger than 4.5 gallons. I usually see much smaller.

 

[MrInfoPhilly]

I may stand corrected? But I have never seen a residential expansion tank larger than 4.5 gallons. I usually see much smaller.

here is a chart for expansion tank recommendations
https://www.amtrol.com/wp-content/uploads/2022/04/MC8520-04_22-TXT-Sizing-Chart.pdf

 

[Twowaxhack]

You can also have multiple smaller tanks. It doesn’t have to be one tank.

 

[AWalt]

I’ve got a 75 gallon tank and a 4.4 gallon expansion tank. It looks like I’m good according to the chart. Static pressure is about 65PSI.

 

[AWalt]

The Grundfos MQ pumps have had a huge increase in price. I can't imagine why. There is a delay when the pump calls for water boosting and the boost is not really very significant. Maybe 30PSI more max. I guess it has a lot to do with water volume and supply pipe size. I'm definitely switching to Valveman's suggestion when my MQ-45 fails.