Some Questions From a Newby

[pedro]

Not sure a Cycle Stop is for me? I've toured the site/forum and done some calculations but don't have a good feel for what I need.
Here's what I have now:
Private well: 7gpm pump at 300ft, 3/4hp, 230v, PH1, 1" black plastic supply line to pressure tank.
Pressure Switch: Square D, 30/50 set at 30psi cut-in and 50psi cut-out
Present Pressure Tank (needs replacement, 15 years old): WellxTrol WX-202, 20 gallon, Draw down at 30/50 = 6.8gal
We are a two person family with low water demands. 2 1/2 bath, dishwasher, new front load cloths washer (low water use)

1. I'm concerned about back pressure in the water supply line. If the Cycle Stop restricts flow then pressure will build in the supply. Is there not a chance of rupture of the supply line? Why does the pump not over heat pumping against flow resistance?

2. I have tried to research what size pressure tank to use but still don't have a good feel for what will work best. Two low flow toilets use 1.6 gallons per flush, other low flow uses 1.3 gallons per flush. Washing machine uses about 12.67 gallons for a complete cycle (about 1 hour), sprays a little here and a little there it seems.

3. Valve selection came up with CSV150, CSV1W, CSV1Z. CSV150 is plastic while the other two are bronze and the CSV1Z is adjustable while the other two are fixed. Any suggestions as to how I should pick? Can I mount the valve in the crawl space before my pressure tank? I have some silt that I remove with a whole house filter, will that effect the Cycle Stop valve?

4. Should I be using higher cut-in, cut-out pressures for a Cycle Stop? Would 60psi cut-out work better than 50psi?

5. The biggest advantage I can see for the Cycle Stop is constant flow applications (such as lawn watering) as the pump will not cycle, but for low usage, short run cycles there appears no advantage for Cycle Stop - am I correct??

Thanks in advance for your help and patience.   
 

[pedro]

Thanks for the great reply.

The water filter I have is Whirlpool DWHBB that is rated for 100psi and uses a 25 micron filter. It has 1" threaded connections so it appears the filter would work in this application before the CSV. Would that assumption be correct? Can I then use the plastic CSV1 as long as I don't want to control pressure?

Are you saying that a larger pressure tank actually works against the best operation of the CSV and constant water demand such as for a shower?

I was thinking that I didn't want the pump to cycle for a toilet flush (1.6 gal) so would pick a pressure tank with a 2 gallon draw down, which would mean a WellXTrol tank model WX-103 with tank size being 7.6 gallons and draw down at 30/50 = 2.6. Would that work OK?

If I set my pressure switch to 40/60 and used a 50 PSI CSV what would be the operating pressure of the system? Would you not have to set the CSV to 60 psi with a 40/60 to get 60 psi operating?

 

[Cary Austin]

The water filter I have is Whirlpool DWHBB that is rated for 100psi and uses a 25 micron filter. It has 1" threaded connections so it appears the filter would work in this application before the CSV. Would that assumption be correct? Can I then use the plastic CSV1 as long as I don't want to control pressure?

Your pump can build 173 PSI.  You can’t use a filter before the CSV that is only rated at 100 PSI, unless it is at least 170’ to the static water level in your well.  If it is more than 170’ to water, you will have less than 100 PSI before the CSV, and you can filter before the CSV.  If you can filter before the CSV, then the CSV1-50 valve will work fine.  If you can’t filter before the CSV, sediment will make the CSV1-50 leak, so use the CSV1Z.

Are you saying that a larger pressure tank actually works against the best operation of the CSV and constant water demand such as for a shower?

Larger tanks with a CSV actually give you the best of both worlds.  You can use a lot of water from the tank without the pump even having to start.  But when you have long term uses of water, the CSV still maintains a constant pressure and keeps the pump from cycling to death.  However, with a large tank, you have to live with decreasing pressure in the shower as the tank empties.  You maybe half way through a shower, while the pressure decreases to a trickle and the temp needs more adjustment, before the pump starts and the CSV starts delivering constant pressure.  With a small tank, the shower will have constant pressure before you get the temperature adjusted in the shower, but the pump will have to come on for every flush or two, depending on the size of tank you install.  So it is a trade off.  But the difference in the number of cycles doesn’t normally justify a larger tank, and with the small tank you have good constant pressure all the time.

I was thinking that I didn't want the pump to cycle for a toilet flush (1.6 gal) so would pick a pressure tank with a 2 gallon draw down, which would mean a WellXTrol tank model WX-103 with tank size being 7.6 gallons and draw down at 30/50 = 2.6. Would that work OK?

See above.  You are talking about the difference between 1 flush and 3 flushes before the pump starts.  It is not going to make much difference.  Actually you will find that a sink or shower is normally used at basically the same time as the toilets, so the pump is already running and there is rarely an extra pump cycle for flushing.

If I set my pressure switch to 40/60 and used a 50 PSI CSV what would be the operating pressure of the system? Would you not have to set the CSV to 60 psi with a 40/60 to get 60 psi operating?

The pressure switch off setting always needs to be higher than the setting of the CSV.  If you want 60 PSI operating, you need to run a 50/70 pressure switch.