Grinder pump question

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Ballvalve

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http://www.spiraxsarco.com/resource...torials/pipeline-ancillaries/check-valves.asp

Have a read about check valves. But mainly you need to understand that a larger check valve does not require any larger forces to open, unless it is designed to have a high pressure spring for fast closing. the only issue is that the check valve be designed to a proper size for the FLOW rate, so that it does not 'chatter'. A 12" check valve opens at the same rate as a 2" check valve, provided that the pressure entering the valve exceeds the static head pressure on the 'other' side of the check valve.

I would suggest looking at some basic hydraulic text books for an understanding of this.
 

Hackney plumbing

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http://www.spiraxsarco.com/resource...torials/pipeline-ancillaries/check-valves.asp

Have a read about check valves. But mainly you need to understand that a larger check valve does not require any larger forces to open, unless it is designed to have a high pressure spring for fast closing. the only issue is that the check valve be designed to a proper size for the FLOW rate, so that it does not 'chatter'. A 12" check valve opens at the same rate as a 2" check valve, provided that the pressure entering the valve exceeds the static head pressure on the 'other' side of the check valve.

I would suggest looking at some basic hydraulic text books for an understanding of this.

Now that you understand that a 2" pipe doesn't offer any real advantage over 1.5" pipe for frictions loss at the flow rates for a forced sewer.......please understand that the larger the surface area is the more sq inches it contains........PSI stands for POUNDS PER SQUARE INCH.....of what? OF PRESSURE!!!!!!!. So with more sq in of area.......the force exerted on that object is greater. Dont you realize the 2" check valve has more surface area to be acted upon by the head pressure on the other side of it???
why do you think 1/2 pipe has a much higher pressure rating than 8" ??????????? Riddle me that. LOL

By the way.....you dont install spring type check valves in a forced sewer. LOL
 
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Hackney plumbing

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Just a quick question...anyone feel free to jump in. If you were asked to open a door that was being acted on the other side with 75 psi (pounds per square inch) do you think it would be easier to open a door that was 2 sq ft or 4 sq ft?

Keep in mind for every square inch of door area there is 75 pounds per square inch pushing back on it.

The pressure is the same but there are MORE square inches for the pressure to act upon the object,in this case the example was a door.
 

Ballvalve

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That makes as much sense as a horse with wings.

Any size door with 75 psi behind it will open at 75.00000001 psi on the opposite side, dependant only upon the friction in the hinges.

Valveman, how about explaining that to him?

And a good plumber will always use a check valve 1 or 2 pipe sizes larger than the main run, due to the large head losses and turbulence caused by most of the designs.

why do you think 1/2 pipe has a much higher pressure rating than 8" ??????????? Riddle me that. LOL

Are you inquiring about schd 40 PVC, radiator hose, 8" agricultural PVC 25 pound head pipe, Yellowmine o-ring joined mining PVC, steel gas line, oil well drill pipe, or aquarium tubing?
Your question is a riddle.
 
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Hackney plumbing

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That makes as much sense as a horse with wings.

Any size door with 75 psi behind it will open at 75.00000001 psi on the opposite side, dependant only upon the friction in the hinges.

Valveman, how about explaining that to him?

And a good plumber will always use a check valve 1 or 2 pipe sizes larger than the main run, due to the large head losses and turbulence caused by most of the designs.



Are you inquiring about schd 40 PVC, radiator hose, 8" agricultural PVC 25 pound head pipe, Yellowmine o-ring joined mining PVC, steel gas line, oil well drill pipe, or aquarium tubing?
Your question is a riddle.

The larger check valve will chatter......the pressure varies not only static but also the dynamic pressure varies while the pump is operating. There is absolutely no benefit upsizing the pipe from 1.25 at the pump to 2" service line and then connect to a 1.25 or a 1.5" forced sewer tap. Absolutely NONE. Solids would collect on the side walls and the head pressure would be worse. 1.25 and 1.5 will stay clean naturally by the action of the pump. This will cause alot of turbulence and ALOT of friction loss.

Dont you understand the difference in the friction loss at the pump rates a forced main uses over a 200 ft distance is only about 1 psi? And that would be lost by the turbulence your larger check would create and the walls of the pipe would get sticky causing even more pressure loss than a smaller 1.5" pipe.

So to sum it up.....Its not a good idea at all to increase the pipe size to 2" connecting to a 1.25" sewage pump connecting to a 1.5" forced sewer. No matter what the distance......if the friction loss becomes to great,you increase the size of the pump and the line your connecting to at the city.

Try looking at the difference between the max pressure 1/2" compared to 8" of copper or pvc.

Increasing the size of the checks is a waste of time and money and causes turbulence/friction loss. It also can chatter,especially in a forced sewer.

Pumping to an open pipe is totally different than pumping into a pipe with substantial head pressures.
 
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Hackney plumbing

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In a forced sewer application the pump turns on and starts to pressurize the outlet pipe and starts to flow that builds pressure. This pressure acts on the flap of the check valve when it build enough head and flows into the citys main. The problem is the pressure can surge in the city main and often does when another seweage grinder starts to operate. The pump does not respond as quick as the pressure surge and the check valve slams shut then the pump builds enough pressure to open it back and this cycle repaeats over and over and destroys your check valve.

Dont over size your swing checks in a forced main or you will be sorry. A forced system is a very dynamic system and has a life of its own with pressures and flow both being considerations.
 

Ballvalve

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So to sum it up.....Its not a good idea at all to increase the pipe size to 2" connecting to a 1.25" sewage pump connecting to a 1.5" forced sewer. No matter what the distance......if the friction loss becomes to great,you increase the size of the pump and the line your connecting to at the city.

Without posting a pipe flow rate and friction calculator here, "no matter what the distance" [and one may assume you mean the head as well] is incorrect. Unless you can find a grinder pump that outputs 300 or 400 PSI, you will need INTERMEDIATE pump stations on long runs and high heads in order to preserve your belief in 1.5" pipe. I hope you know that at a certain point in length and head, a pump outputting even 500 psi will allow a little pee type stream to exit the pipe. I don't think your sewage or tie in would be particularly successful with your theory.

you increase the size of the pump and the line your connecting to at the city.

What does that mean, increasing the size of the line you are connecting to at the city?

Good to see you didnt go back to the PSI to open a door issue.
 

Hackney plumbing

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Without posting a pipe flow rate and friction calculator here, "no matter what the distance" [and one may assume you mean the head as well] is incorrect. Unless you can find a grinder pump that outputs 300 or 400 PSI, you will need INTERMEDIATE pump stations on long runs and high heads in order to preserve your belief in 1.5" pipe. I hope you know that at a certain point in length and head, a pump outputting even 500 psi will allow a little pee type stream to exit the pipe. I don't think your sewage or tie in would be particularly successful with your theory.



What does that mean, increasing the size of the line you are connecting to at the city?

Good to see you didnt go back to the PSI to open a door issue.

The e/one grinder pumps will pump horizontal through a 1.5" pipe for over 4,000 ft. If it had to go further the answer would never be increasing the size of the forced main on the customers property.......it would require a bigger pump and the bigger pump would have a larger outlet. You simply never just increase the customers service line.


It means the city would need increase the size of their line to match the size of your line. You'll never see a 2 or 3" lateral line for the typical property...those are the size lines you find out in the main lines the city uses.

The door under water is exactly true. Until the pressure equalizes on both sides of the door the larger door will be much harder to open than the smaller one because theirs more surface area for the pressure to act on.
It really wouldn't be a problem if the citys pipe would maintain a constant pressure but it doesn't......the citys pressure varies ALOT. One second the main may have 100 psi 1/2 second later its 60 psi then maybe up to 80.....etc etc. This will cause all types of problems with over sized check valves and the pump itself.

Thats why you get the system engineered with the help of the system provider and you do not deviate. They know what works on their system now and what will work in the future as they design the sytem and more homes are connected. If you just go buy a pump that will work today with the system it may not work tomorrow when another house is added to the line and the pressure increases. You would simply have to replace the pump every time they added more people to the sewer. Thats why the city is specifying the pump and the size lines. If you follow their specifications and next year the pressures are too great for your pump to work.......THEY will have to get the system back to the specs and pressures it was designed for. So while you may get by with a cheaper pump today,next week you may be buying another one if you do not follow the specs.

To sum it up you simply do not size a forced sewer main like you do a water main. You do not worry about friction loss due to pipe size. You use the size line the city haprovided for the tap connection at the street. Over sizing WILL cause problems. The pipe will not clean itself and chat chat chat chattering swing checks that can damage the check valve and make the pump work harder.
 

Hackney plumbing

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The reason why I said at any distance is because the pump has no problem pumping the typical distances for a home. For the E/one pump a couple hundred feet is not even worth talking about......1 psi loss is not an issue. The E/one pump has a cut off head of 185' and can generate up to 40% more for up to 5 minutes. Its pump curve is almost VERTICAL. It has a 1.25" outlet.
 

WynsWrld98

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Can someone recommend a reliable sewer pump/grinder to replace a eOne 2000 series? Mine breaks about every year and I'm sick of dealing with it, want to find a more reliable one with good warranty.
 
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