Advice:Constant vs Std. system

I am replacing an old 1hp 230v Franklin pump and an old gavanized Monitor pressure tank(50gal or so?), no bladder.
Well is 200ft. I'm not sure of static water level, which is really important I know.
My needs are that I want to run a sprinker system and water my garden, trees, and flowers. (Our home is on city water)
The sprinkler system has three rainbird heads per station, 6 stations total. I usually run each station 30 minutes twice(cooler months) to three times a week(July). The heads put out 2-3gpm depending on the nossle. So 9gpm max per station? (Math right?) So that's around 3 hours of constant watering 3 times a week in peak months.
The old pump and motor short cycled because the old tank lost pressure and burned up my motor.
This system normally, with the pressure switch set at 40-60. after 20 min. or so would drop to 20psi and wouldn't hardly push my heads on the sprinkler sytem. 30-40psi pushes the heads adequately.

I was told to look at the two options:
Option1. Get a Amtrol WX-250 tank (44gal) bladder tank which I will install and have my pump and motor pulled and replaced and I would be in business. Will probably be a Grundfos 1hp 230v. I've also been hearing people talk about the CSV(cycle stop valve) and would like to consider that too.

Option2. My neighbor is convinced I need the new Grundfos smartflo constant pressure system. It looks expensive. The well guy said it will be more to install obviously because the manifold, tank and control box will need to replace my existing system. But the tank cost is less. I've heard these variable speed pumps may not last as long?

Any advice would be much appreciated. Which one is easier to maintain? I can do with a little more installation cost if the constant pressue system will be that much of a superior system. However, if pressure is the only benefit I can deal with my heads not being pushed as well.

Also, would you ever consider pulling a pump with a tractor loader and pipe dogs or go ahead and let the well company do it? Drilled in the 1960's. Not pulled since then I don't think.

Your maximum water usage is the sprinklers. The pump should be selected to run the sprinklers below the shutoff pressure of the the pressure switch. You can find that point from the characteristic of the pump and adjust with pressure switch settings and selection of nozzles. If you have any local sprinklers or drip points that you want to run you might be able to put them on the same cycle as the sprinklers, or even on multiple cycles.

The objective is to match the main flow to the pump to let the pump run continuously with the main sprinklers without shutting off the switch and without requiring any control such as variable speed pump or CSV.

If you have some low or intermittent flow conditions, such as hand watering or small sprinkler flows that are well below the capacity of the pump, you could put in a CSV with a regulated pressure between the main sprinkler pressure and the shutoff pressure of the pump. That would minimize the cycling for those occasions.

EXAMPLE:
If your sprinklers require 9 GPM at 40 psi then you might set the pressure switch at a wide range of 35 to 65 psi. If you have a 60 psi CSV (the kind with no significant pressure drop) then the CSV will not cause any pressure loss when you are running the main sprinklers.
http://www.grainger.com/Grainger/items/2DC10

The shutoff pressure of the pressure switch must not exceed the pressure capability of the pump at minimum rated flow of the pump.

The WX-250 that you are considering will handle up to 125 psi and has an acceptence factor (the fraction that can be filled with water without damaging the bladder) of 0.77. The high acceptance factor is important when the pressure switch has a large range.
http://www.amtrol.com/pdf/MC4380 06_07WXTBrochure.pdf

When the main sprinklers shut down the CSV will let the pump continue to run as long as the demand is about 1 GPM or more. You want to keep that portion of the cycle as short as possible to save power.

With the requirements that you describe I don't believe you need a variable speed pump. The CSV will let you operate at low flows without affecting the main irrigation flow. By setting the STOP point of the pressure switch at about 5 psi above the CSV regulation pressure it will not run too long after you stop using water.

You want to match the pump and sprinkler so you will be operating below the CSV regulation setting during most of the cycle.

Thanks for the quick reply

Thanks for the great advice!

Sounds like I should probably end up going with the std. system w/CSV.
Once they measure my static water level and consider the gpm of the sprinklers I will be able to choose the appropriate Grudfos or Franklin std. pump and CSV? I think those are the brands my well guy uses.

As far as tanks:
Others have suggested going with another brand of pressure tank than Amtrol to save $. For instance they suggested getting one from Ace which is near us. Otherwise the Amtrol from our well guys is full retail($600). Do I pay full retail or will the 44gal Ace tank work just fine $280?
Or order the WX-250 online for $410 (includes shipping) if I gotta have the Amtrol?
Also, do you suggest I replace my older manifold with newer brass? It has older steel fittings.

Thanks

Even the cheaper tanks will last longer when you use a Cycle Stop Valve. The bladder in these pressure tanks will break from cycling on and off just like bending a wire repeatedly. The CSV will all but eliminate the cycling and makes the pressure tank and everything else in a pump system last longer. Although I would stay with one of the better tanks such as Amtrol, Flexcon, or Well mate.

See these links;

http://www.cyclestopvalves.com/homeowners_3.html

http://www.cyclestopvalves.com/comparisons_14.html

I would replace the manifold with a brass manifold. At 10 GPM you can use a 1" manifold but 1 1/4 doesn't cost much more.

The manifold has ports for the relief valve, gauge, drain, and pressure switch.

If you use the adjustable CSV1W it will have, and you must account for, about 5 psi pressure loss at 10 GPM. The plastic CSV1 has less pressure drop but is not adjustable and is usually installed in the well casing where you would have to pull the pump to service it.

Thanks again to you guys. You are telling me what my well guy probably won't because he wants me to spend more $ and have him keep coming for service calls.
I think my old tank has a 1 1/4" fitting. And the Amtrol WX-250 takes 1 1/4".

Also, where do I get a CSV and which adjustable one do you suggest? Is there a website you like (Grainger maybe?), if my well guy doesn't have one?

And where is it installed on the manifold in relation to your pressure switch? Do some manifolds come with a spot to add the CSV?

What size tank would you suggest? Can you have too big of a tank? I know I don't need anything larger than 50gal for sure.

I would not use any smaller than a 20 gallon size bladder tank. Larger won't hurt anything but, won't help much either.

I'm assuming if I select the correct 1hp pump (Grundfos 10SQE10-290 (based on my 280foh requirement)) it will run continuously for 3 hrs at or near 40 psi. and push three rainbird heads rated around 3gpm/ea? Or do I need a CSV to do that.
Assuming I have a tank around 40gal.

The SQE in the middle of that number means 3" diameter, 10,000+ RPM, electronics in the motor, variable speed, etc. You need a 10S10-15 that is 4" diameter, 3450 RPM, no electronics, etc. More like your old pump. Don’t have my books in front of me now but, that pump will still probably try to produce 10 GPM while you are using only 9 GPM. That is what causes cycling and what a CSV prevents. You can always crank up the pressure switch a little or size the nozzles larger if needed to keep the pump running continuously. If all you always run 9 GPM every time the pump is running you can get away without the CSV. Without the CSV you would need at least a 40 gallon size tank and a 80 gallon size would be better. With the CSV a 20 gallon tank is plenty large and you can run water anyway you want.

“(Our home is on city water)â€

After rereading your post, why do you even have a pressure tank? You could run this from the sprinkler timer and not even use a pressure tank or switch. Of course if you have the tank so that you can also use garden hoses and such to water with, then you will not always be using 9 GPM and the CSV and pressure tank become very important.

Like you are saying once in a while I will use the hose to water dry spots, water the dog and such. So the demand will likely be less than 9gpm in some situations.

The CSV1W which is adjustable looks like the one I need with a 20gal tank and 10S10-15 pump?
I'd rather not use the preset CSV that is intalled w/ the pump(good choice?).

Anyway, I really appreciate all your advice! It will undoubtably save me time and money.
Thanks!

My rule of thumb is that anything that you water while you are holding the hose, won’t cause much cycling. Anytime you lay the hose down and walk away, cycling can become a problem. Those little tractor sprinklers can be the worst thing for a pump without a CSV. If you never lay the hose down, you can get by fine without the CSV. That is just something I have never been able to do around my house, and with a CSV, I never have to worry about it.