Siphon VS. Pump

that is understandable, Im not saying in this case its wrong. It was my experiance that I had good luck with them. I use one once, and it work for a year before the tank had to be taken down. If you have seen them fail that much, I am glad I didnt need a valve for this tank;D

 

It makes no difference where the valve is placed inline, head is head and is measured at eithere the centerline or discharge of the pump. If I put the valve right on the pump or if I place it at the display, the pump still sees the same head or backpressure either way.
Work is measured as the amount of water pumped, not how high you pump it. Raise the exit point or add head via an inline valve and you get less water out the end or less work done and lower power consumption.
Stick a tee and a valve leading off that tee back to your sump and you are still getting x number of gallons up to the display but you are also expending the enery (work) to produce that water returning to the sump too. More water is being pumped, thus more work and higher power consumption.

Here is a link that partially explains it and shows a simple graph illustrating the difference between throttling a pump discharge and returning the flow to the sump or suction side of the pump. You can clearly see throttling the pump is the better choice between the two and varying pump speed with a variable frequency drive is much better than either but not pratical for our purposes. We use VFD's in large pump applications like treatment plants and such.
Discharge Regulation of Centrifugal Pumps


If precise control of flow is needed then you want a needle valve or a flow control valve both of which are designed for just that purpose. Ball valves are cheap and work well while gate valves may give you more precise control but gates are not designed nor intended for throttling either.

 

After finding out that the info on Wikipedia pages can be changed by anyone with a computer, I stopped putting my complete trust into it. How many people have computers??? Plus when all my professors stop taking it as a acceptable resource for research papers, i put my trust somewhere else.

 

I regained my faith when I learned how to look at the list of edits done to any Wikipedia page, and when I can use other resources to back up the Wikipedia facts.

In this case, I have firsthand experience, and used Wikipedia as a reference to something I already knew.

 

Im not question your xp. I told you my little bit with gate vs ball (ps I had a ball valve almost break my plumbing because of how hard it was to move the handle. I wasnt adjusting it of coarse)
how do you look up if edited or not?

 

Look up.....if....edited?

Nonononono. You can look up what each and every edit was and compare the history of the article that way. It completely eliminates the possibility of bias from entering the article and fooling you, then being changed back. Just look at whether the post is done from a raw IP address or by a user to find out 90% of the time.


There's also talk pages about every article that can explain why certain choices are made about the information that's included and excluded from the article. That's in the top left, under "Discussion".

 

Done have grammar good no....

That gives Wiki a little more credit

 

Did what say then you?

 

Mag Drive Pumps

That's just one warning from the manufacturer. Back pressure on mag drive pumps causes more heat.

You can't micro adjust a ball valve, especially the everday type you buy in hardware stores. If they were meant for simply on/off every standard sink, bathtub and shower would use ball valves. High end skimmer manufacturers use gate valves. Why? because micro adjustment is needed that is too hard to get with a ball valve. Gate valves wear out quicker than ball because of the o rings. Ball valves get hard to turn because of build up on the ball but are alot easier to get working again.

All of your answers are always textbook variety and I know why now.

 

Back pressure causes heat because the same amount of energy would always be used by the pump; AZDR's argument was about the energy usage. Heat doesn't cause wear on a component like an induction motor, except, again, for possibly the impeller. Don't confuse the concepts.

The optimal working of a motor is designed for a specific amount of backpressure, so of course they're going to say "designed for free flow" if they design the impeller for no backpressure. It's a simple matter of switching the impeller (just the small piece of plastic) to have a pump with a better efficiency for an environment with backpressure.

Unfortunately, every bath, shower and sink doesn't use a gate valve.

You have a hard time microadjusting your ball valves on the tank because they're made of PVC, which sticks, unlike the metal ones you use many times, every day.

I really do hope you weren't thinking I read up when I don't know something in order to help myself and the people asking questions. That would be a travesty.