Weird pump questions that might be difficult to answer

[Superjustin13]

I've attached a picture of my question.

You can see that the incoming water piping size to my house is 1.5". You see where the relief valve, expansion tank and transducer are. When they reduced the 1.5" pipe to 3/4" pipe. How much volume am I losing from that reduction? I know its such a tiny run, but you can see where the bladder is, having to go through .75" reduction and then having the water have to turn from the cross, and go into the pipe. Would upgrading it all to 1.5" help with supplying volume to my bladder any faster? Also, you can see in the picture. Would it be a better idea to put my bladder on top of the cross, and put the transducer where my bladder is? Could upgrading the 3/4" piping to 1.5" and moving the bladder on top of the cross help?

The reason when I ask is, because when I have my irrigation on and there is a big demand for instant water. My bladder can't fill fast enough because of the pressure drop and it causes my bladder to slam down and cause a water hammer in my house.

I know the solution to that problem is, lower the demand on the irrigation ( which I can't do at all ) or increase the pump size.

But my question still stands, would moving the bladder to the top of the cross, and moving my transducer to the bladders original location, and increasing the piping size help with filling the tank faster than its currently being filled when theres a pressure drop?

Its a VFD system, not a CVS. I understand the pressure tank is a shock absorber. According to the manufacturer. a 40-45GPM system should be using a 9 gallon tank. The one I have is 4.4 gallon. It definitely need more shock absorber.

Do you think upgrading to a 10.3 gallon tank, and increasing my piping size to the bladder help my problem?

 

[Valveman]

A 4.5 gallon size tank only dumps about a half gallon of water before the pump starts. And it will dump plenty fast through that 3/4 line. The problem is the slow start of the VFD. Your sprinklers are running out of water and the bladder in the tanks slams the bottom while the VFD is slowly ramping up the pump speed. This has always been one of the major problems with a VFD, they have a programmed time for ramp up and ramp down. A VFD is always a few seconds behind the change in water pressure. This is unlike a CSV which reacts instantly to any change in pressure and quickly adjust the pump output to match the demand. The instantaneous reaction of a CSV keeps the bladder from bottoming out and causing water hammer like a VFD.

If you can get into the VFD programming and increase the reaction time it would help. Otherwise a larger pressure tank with a really low air charge will give the VFD an extra second or two to get ramped up before the tank bladder hits the bottom. But replacing the VFD with a CSV would be a better fix.

 

[Sponsor]

 

[Reach4]

But my question still stands, would moving the bladder to the top of the cross, and moving my transducer to the bladders original location, and increasing the piping size help with filling the tank faster than its currently being filled when theres a pressure drop?

Moving the newer bigger tank would seem more mechanically better, than to have the heavy tank out on that arm.

Note that your better precharged tanks use a diaphragm rather than a bladder.

 

[Superjustin13]

Valveman, do you think upgrading from the 3/4" to 1 1/2" would help me even the slightest bit? If it would help me at all, I will be more than happy to replace it all.

Also, I need an inline tank. I currently have the WX-102 which is a 4.4 Gallon 3/4" pipe diameter.

I am thinking about upgrading all the fittings to 1 1/2" and getting the WX-200. It is a 14 gallon 1" threaded tank. It is massive compared to the 4.4 gallon tank. It is also about the size that Gould recommends for my GPM.

I could also try the WX-104. It is a 10.3 gallon tank with 1" diameter. That tank weights 2LBS less.

If you look at the set up, if i put a larger tank in, Wouldn't i need to support the pipes coming out of the wall more? The weight on a WX-104 or WX-202 is 20/22 pounds dry. I would be worried with those big tanks on then filled with water would really weight down my pipes. I would think about adding support legs on the pipes.

I would have to get a cable, but would increasing the reaction time be something I would be able to easily do?

 

[Reach4]

My bladder can't fill fast enough because of the pressure drop and it causes my bladder to slam down and cause a water hammer in my house.

A diaphragm slam does not occur while the tank is filling, but rather when it empties.

 

[Valveman]

Increasing pipe size to the tank is not going to help. That tank only has a 3/4 outlet and the WX200 only has a 1" outlet, so 1 1/2 pipe won't help if the tank outlet is only 3/4" or 1".

You will have to go into the programming to increase the reaction speed of the VFD. Some brands are easy to do and other brands are not.

Just reducing the air charge in the tank you have will buy you some time for the VFD to ramp up. Decrease the air charge to about 20 PSI and see how it works.

 

[Superjustin13]

Increasing pipe size to the tank is not going to help. That tank only has a 3/4 outlet and the WX200 only has a 1" outlet, so 1 1/2 pipe won't help if the tank outlet is only 3/4" or 1".

You will have to go into the programming to increase the reaction speed of the VFD. Some brands are easy to do and other brands are not.

Just reducing the air charge in the tank you have will buy you some time for the VFD to ramp up. Decrease the air charge to about 20 PSI and see how it works.

The air charge is already 20PSI in the tank. I have the controller set to 5PSI drop and not 20PSI. I have the Goulds 3AS30 controller. Do you think I should increase the tank size at this point? The WX104 or the WX200?

 

[Valveman]

That might be a good Band Aid. It is the variable speed controller that is the problem. There are a lot of other problems that you will probably have with the VFD, but the larger tank MIGHT help with the slow reaction time and the tank bladder hitting the bottom. The larger tank won't help with all the other problems of a VFD, but it might help with that one.

 

[Superjustin13]

Would you recommend me getting the 10.3 gallon or the 14 gallon tank? by my math according to the manufacturer the 10.3 gallon tank is 20% of my actual GPM my pump produces.

Also, would I be able to move my Transducer to the side of the cross? I would have to do this if I purchase a larger tank, because it is 4" in diameter larger, and I would hit my softner pipes. So i would have to move the transducer to where I circled it.

Would that pose any problems, it would also be directly right next to the tank.

Also, thank you everyone for taking the time to help me in this process!

 

[Valveman]

The larger the tank the more time the VFD will have to catch up. Moving the transducer shouldn't be a problem. It just needs to be fairly close to the tank.

 

[Superjustin13]

Okay, so moving the transducer Horizontally shouldn't be a problem. What about all the weight from the bigger tank? Should I make some support legs for my pipes with all that added weight?

Thanks for answering my questions!

 

[Valveman]

A 14 gallon tank only holds 3 gallons of water, so less than 30 pounds. But if that bladder in the tank breaks, and they all do eventually, that tank will weigh 120+ pounds and will break the pipe it is hanging on. So yes I would strap it to the wall or something.