Most people who think about valves think about valves controlling flow, including me. YES, this valve will stop flow under the conditions of your system. NO QUESTION this valve will stop flow. You've got the right valve for that. Absolutely. Complete agreement.

You're not trying to stop flow. As you've designed it, your pump is off, what flow? You're trying to conserve system pressure. Can this valve conserve system pressure? Yes.

**** Can it conserve system pressure if operated simultaneously with pump shut-down and no pressure tank reserve? ****

Well, that's certainly not what it's designed to do and I doubt anyone has attempted that application - so you might be the first. Knowing how the valve works, I'd say there's a small chance that it might "capture" some, since you've placed it upstream of the throttle. But I'm still not seeing this valve closing too quickly with 17.6 GPM rushing past. It's only a weak spring and/or gravity doing the closing in this type of valve. Will it close? Yes, sooner or later, and with flow that's good enough. Fast enough to save your gone-in-a-blink pressure???

But let's say it can "save" all the pressure with your current design, or you add the pressure tank and pump pressure switch and it all works great. The system is pressurized on one side of the valve and under vacuum (or atmosphere) on the other. At this point, the semi-direct lift valve is under higher differential pressure than can be dealt with using the solenoid alone. It will change "modes" and operate as a pressure actuated valve complete with tiny pilot hole. Capiche? Sorry if you were sold on something else.

A vacuum break on the discharge line (what joe called the "drain") will admit copious amounts of oxygen - not what you want with high Fe content. If Joe sees problems in drains with high Fe content, it's gonna get worse if you're admitting oxygen. Don't even think about it if you're discharging to another well. If the tail-end of your "drain" is open to atmosphere in one form or another and otherwise not submerged underwater, the discharge pipe will not retain its vacuum for too long after the flow stops.

So what I have is:
pump
droppipe,
union,
isolation valve,
drain,
check valve,
pressure gauge
xp tank,
union,
HX,
union,
check valve
solenoid valve w/o tiny pinhole,
drain,
throttle valve,
drain for flow measure,
pipe to well,
union,
drop pipe into aquifer

:D

By including the bladder tank, this design will work. Now it's a question of economics and optimization. You'd need a fairly sizable bladder tank to ensure enough time to close the valve without losing too much pressure. Your system will still lose a little pressure, but not too much.

Versus, the way everyone else does it: A very small (cheap) bladder tank and a very cheap pressure switch to control the pump. As a bonus, system pressure at shutdown will be higher than operating rather than lower. Bonus, bonus, no motor control relay required. Relays are probably the number two failure point after valves...

Definition of Semi Direct Lift copied from fluidprocess.com

These valves are used where full-flow is needed, but where a 5 psi differential may not always be available. This type operates similarly to the piston-pilot type, except there is a mechanical linkage of the plunger and the piston assemblies. The solenoid can then lift and hold open the piston assembly, after the internal pressure has been unbalanced by the pilot opening. It will then hold the valve open with low or high flow (even to zero psi differential).
Some applications would be:

Pressurizing a tank to full source pressure
Process shutoff in a closed circulating system (especially where low flow and low system pressure is specified)
Large vacuum systems
Suction line shutoff to a pump
Other applications where a minimum 5 psi differential is not always available

Have fun cleaning out your tiny pilot port. You'll get faster at it over time

Posted By Blake Clark on 28 Jun 2012 08:40 AM
By including the bladder tank, this design will work. Now it's a question of economics and optimization. You'd need a fairly sizable bladder tank to ensure enough time to close the valve without losing too much pressure. Your system will still lose a little pressure, but not too much.

Versus, the way everyone else does it: A very small (cheap) bladder tank and a very cheap pressure switch to control the pump. As a bonus, system pressure at shutdown will be higher than operating rather than lower. Bonus, bonus, no motor control relay required. Relays are probably the number two failure point after valves...

No relay in the solution I provided. The solenoid is connected to C2, outside water source, motor control

Definition of Semi Direct Lift copied from fluidprocess.com

These valves are used where full-flow is needed, but where a 5 psi differential may not always be available. This type operates similarly to the piston-pilot type, except there is a mechanical linkage of the plunger and the piston assemblies. The solenoid can then lift and hold open the piston assembly, after the internal pressure has been unbalanced by the pilot opening. It will then hold the valve open with low or high flow (even to zero psi differential).
Some applications would be:

That may be how that product is described, but not necessarily all solenoids operate in such a fashion.

Pressurizing a tank to full source pressure
Process shutoff in a closed circulating system (especially where low flow and low system pressure is specified)
Large vacuum systems
Suction line shutoff to a pump
Other applications where a minimum 5 psi differential is not always available

Have fun cleaning out your tiny pilot port. You'll get faster at it over time

Later on, after we aren't posting here, and if the site masters continue to pay ICANN and the web host, perhaps someone will be looking for an answer and arrive here to sort through all the chaff to get to substance of the question.

What we have determined is that in a cold climate, with an open source well, for about a 4 ton system, 4gpm per ton is a bit on the high side, but may provide headroom against freezing.



Piping became a question. Blake, you provided some clues to your own system, without providing the youtube video, diagram or enough nouns and verbs to adequately describe your solution.

Idronics Manual 9, provides a decent diagram for such an open system with a solenoid valve and it is reasonable to assume that, on the contrary, someone does it this way.

Blake, you haven't provided your famous downstream solution.

but I'm not going to quite yet

nooboo, your post of 28 Jun 2012 12:29 AM looks correct. I would size the pump for and set the pressure switch to the pressure needed to get the desired GPM with the throttle valve almost fully open (to leave a little bit of pressure and margin). I would set up the piping so that it is very easy to clean the heat exchanger with acid. And use oxygen barrier piping.

Ah, well. It would have been fun to know there was a sister-system up in God's Country. Good luck! Let us know how all the parts come together and when you're finally ready to throw the switch.

Parts are coming together: We got two 8" shallow wells in with an air knife.

Posted By Blake Clark on 05 Jun 2012 06:46 PM
(There's a guy that's been banned from the site who claims you actually save a lot of energy by throttling flow - did I mention he's banned?).

I think what that “guy” says is throttling a pump can save almost as much energy as a variable speed pump. Both will actually increase the energy used per gallon compared to a perfectly sized pump. But when the pump has multiple jobs or there is some other reason the pump cannot be sized perfectly, varying the flow with a valve has many advantages. Many people tell me the additional installation and maintenance costs of a variable speed pump far outweigh the energy savings of an open loop heat pump. I agree the most efficient way to supply a heat pump is to keep the pressure low. So a dual pump set up to provide the extra pressure needed only for the domestic use is the most efficient. This can be done easily as in the drawing attached, and the valves can eliminate cycling and make a regular and inexpensive pump system last a long time.

Ever thought about putting a pond loop into the lake...?

Are there metrics for how damaging cycling is. Ie, no question that rapid cycling is hard on a pump, but how many cycles can one expect before it fails?

Every motor has a maximum number of cycles allowed listed by the manufacturer. Smaller motors can survive more cycles than larger motors. Submersibles less than 3/4 HP are allowed 300 cycles per day. 1 though 5 HP motors are allowed 100 cycles per day. 7.5 HP through 30 HP are allowed 50 cycles per day. Larger motors are allowed even less, and usually listed by the hour, not the day. These “maximum number of cycles” are only to help the motor last through the warranty period. Submersible pumps are made for “continuous duty”. They are self-cooling, self-lubricating, and have frictionless bearings. As long as they are running, they are happy. The bearings are only frictionless when above 30hz speed (50% speed). So every time the pump is started, the bearings experience friction until the pump speed is up to 50% of full speed. It is also hard on a motor to re-start it before it has had sufficient time to cool down. Starting a hot motor makes the bearing friction much more damaging. One of the biggest misconceptions is that restricting a pump with a valve makes the pump work harder. Wrong! Even with increased down-thrust from the extra backpressure, the bearings are still frictionless as long as it is up and running. Plus when restricted with a valve, the amp draw of the pump is reduced almost as much as when using a VFD. The reduced amp draw makes the motor run cooler and last longer. All things considered, the fewer number of cycles, the longer a pump will last. One way to look at it is like the motor comes with say 182,000 cycles in the box. The sooner you use up those cycles, the sooner you will need a new motor.

Disclaimer: I am a DIYer.
This is the time for modifications to the system if needed...before back filling.
Two shallow wells are in. I am currently insulated the pipes, prepping for back-fill. Here at my location, we have a deep frost line; I'm concerned about freezing the lines where they enter the house. A closed loop with anti-freeze would eliminate this concern.
About putting Loops in the Lake:
If a loop were to be put into the lake, well, I am not sure that the difficulties, administrative and technical would be easy enough to overcome. First, the lake is an anadromous one with salmon spawning just offshore. The Reds should be here soon. Getting a Dept. of Natural Resources Permit, a Fish and Game Permit, and a State Park permit seems unlikely to happen. Well it might succeed. The Lake is part of a State Park; the Park Ranger told me "No one has ever applied for a permit. Why don't you try!".
We have thick winter Lake ice. and a slowly sloping lake shore, where at 40' horizontal, we might be below the potential freeze level. To get a loop to the stable temps at the bottom of the Lake would require a 'long trip', out and back for the pipe. Spring break-up presents problems with the ice moving, posibly taking equipment with it.
I have room on my property, at the base of a hill where we have a duck pond. I have a couple of years old US Army Corps of Engineers permit to work in and fill that area, so loops could have (perhaps should still be placed)in my pond and back-filled. The ducks aren't using the pond since the Eagles were picking them off for dinner.
Higher EWT is a big plus with the open loop. One neighbor told me his EWT in a closed loop was in the low 20's. That does not seem efficient.
A negative with the open loop is the pump I have chosen will require yearly maintenance. Pumping energy is estimated at 600 watts.
Fouling of the HX is another concern, but I am planning on a yearly cleaning of the solenoid and pump maintenance.
A bit farther along with the 60's Austin Western Blade:

So the idea is to always keep some water running to prevent freezing?

Posted By jonr on 09 Aug 2012 02:44 PM
So the idea is to always keep some water running to prevent freezing?

That is no guarantee. A neighbor, a bit farther north, kept his cold water running to prevent freezing his water line on one extra cold night last year. His septic line froze solid. Two babies in the house, a patient wife; thankfully spring was only a month away!

Probably a good idea to use PEX (somewhat freeze damage resistant) and lay a wire in with it (in case you ever need to defrost it).

The Tsurumi Pump is putting out 20gpm with my static and friction head totals. Have it throttled to 18. The solenoid is holding the pressure when off.

Parts are coming together. The HX on the unit is leaking at a top fitting. Manuf tells me it is PVC, so I might solvent weld it; perhaps heat weld it.

Pre-start-up well temperatures, August 28, 2012:
Discharge Well:
2.3m water depth, 8.38℃, 0.129 SpC, 3.98 DO, 7.06 PH
Supply Well:
4.3m water depth, 6.44℃, 0.163 SpC, 2.33 DO, 6.56 PH

Need a bit of help please: I reversed the Geo source Inlet and Geo Source Outlet with each other. Does it matter to the Source side heat exchanger if the Geo source Inlet and Geo Source Outlet are reversed?

Yes.

Heat exchangers in these systems are designed for counterflow (heat exchange fluids moving in opposite directions) and will deliver rated capacity and efficiency only if counterflow is present.

Making that change is now on my list, Thanks, for now,

I am celebrating the FIRST RUN!!

Outside Air temp = 22f
Inside Room Temp = 62
After 30 mins of run:
GEO inlet = 53.6f
GEO out = 52.16
Inside (Floor) Supply = 79
Inside (Floor) Return = 69