1
Pumps, Wells, Tanks, Controls / Valve sizing calculator
« on: March 28, 2007, 01:26:12 AM »
Looks good! I will spread the word and pass along the feedback.
Show Posts
This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
Pages: [1]
2
Pumps, Wells, Tanks, Controls / Valve sizing calculator
« on: February 05, 2007, 09:12:17 PM »
I had a customer ask if it would be possible to build a valve sizing/pump sizing calculator on our webpage. I think it would help with the comfort level of the distributors and some installers. Some of them are comfortable in sizing pumps and taking into account friction losses and differential pressures, but most aren't.
Could we build something that would ask for pump dead head pressure, flow, static & pumping water levels, and have it tell them which valve models would best fit the application.
Either that or a printable checklist that would guide them through the sizing. It would be another great tool to help our sales.
What I am finding is that there are a lot of inside salesmen who are very willing to sell our valves, but they are intimidated by the BASIC math required to figure out the sytem. If you don't do it every day it can be hard to remember the steps until you start selling a lot of them.
Could we build something that would ask for pump dead head pressure, flow, static & pumping water levels, and have it tell them which valve models would best fit the application.
Either that or a printable checklist that would guide them through the sizing. It would be another great tool to help our sales.
What I am finding is that there are a lot of inside salesmen who are very willing to sell our valves, but they are intimidated by the BASIC math required to figure out the sytem. If you don't do it every day it can be hard to remember the steps until you start selling a lot of them.
3
Pumps, Wells, Tanks, Controls / Water Hammer on Community Water System
« on: February 05, 2007, 09:01:20 PM »
Do you happen to know the manufacturer and model number of your pump?
The 80' of elevation gain could prove to be a problem. Does that home currently use a booster pump?
The 80' of elevation gain could prove to be a problem. Does that home currently use a booster pump?
4
Pumps, Wells, Tanks, Controls / Two Pumps in the same well
« on: February 05, 2007, 07:08:19 PM »
I agree, no news is good news. I haven't heard anything from them. I will be checking in with them in a couple weeks when I am down in that neck of the woods. Last I heard, they were fighting the soft start ramp time on the big pump. If the demand was too much too fast, the pressure would fall off significantly before the big pump ramped up to speed.
That picture turned out all right for a camera phone, huh?
That picture turned out all right for a camera phone, huh?
5
Pumps, Wells, Tanks, Controls / Water Hammer on Community Water System
« on: February 05, 2007, 07:03:42 PM »
Thanks for the info on the cut-in pressure vs. CSV pressure setting Cary.
The tank size is perfect..you will have approximately 12 gallons of drawdown.
I need to know if you have any elevation changes from the wellhead to any of the homes on your system.
Thanks
The tank size is perfect..you will have approximately 12 gallons of drawdown.
I need to know if you have any elevation changes from the wellhead to any of the homes on your system.
Thanks
6
Pumps, Wells, Tanks, Controls / Homeowner VFD or CSV
« on: February 05, 2007, 01:37:45 AM »
It hasn't become an issue for irrigation and domestic pumps yet, but eventually there will be problems with vibration caused by variable speed pumps operating within critical frequencies. I should say, when they have the problem, they don't know what is causing it. All machines have a critical frequency.
In industrial applications, the drives are complicated enough to allow you to actually go in and "lock-out" the critical frequency. As the machine ramps up or down and nears the critical frequency, the drive speeds through it. Lets say that critical frequency is 52Hz. As it is ramping up to full speed, it hits 50Hz and quickly accelerates to 54Hz. It still hits critical speed, but goes through that speed fast enough to keep the pipes from shaking excessively.
Unfortunately, in the groundwater and irrigation industry nobody is going to recognize this problem and if they do, they aren't going to pay the money to have a vibration analyst come out and identify the critical speed. Even if they did, I'm not aware of any drives used in these applications which would allow you to lock it out should it be identified.
I spent nearly 1 year trying to identify the critical speeds of 6 pumps in a pump room using vibration analysis. Once the speeds were identified on each pump, I still had all the piping that had critical frequencies. It seemed it would never end!
I have been on one jobsite with this problem so far and the answer was... add torque arrestors when you have pipes resonating all the way from the pump into the house.
In industrial applications, the drives are complicated enough to allow you to actually go in and "lock-out" the critical frequency. As the machine ramps up or down and nears the critical frequency, the drive speeds through it. Lets say that critical frequency is 52Hz. As it is ramping up to full speed, it hits 50Hz and quickly accelerates to 54Hz. It still hits critical speed, but goes through that speed fast enough to keep the pipes from shaking excessively.
Unfortunately, in the groundwater and irrigation industry nobody is going to recognize this problem and if they do, they aren't going to pay the money to have a vibration analyst come out and identify the critical speed. Even if they did, I'm not aware of any drives used in these applications which would allow you to lock it out should it be identified.
I spent nearly 1 year trying to identify the critical speeds of 6 pumps in a pump room using vibration analysis. Once the speeds were identified on each pump, I still had all the piping that had critical frequencies. It seemed it would never end!
I have been on one jobsite with this problem so far and the answer was... add torque arrestors when you have pipes resonating all the way from the pump into the house.
7
Pumps, Wells, Tanks, Controls / Two Pumps in the same well
« on: February 03, 2007, 04:09:32 PM »
Here is a picture from the installation. It shows the bypass that Jeff had specified and the valve. The installation was done in a vault.
8
Pumps, Wells, Tanks, Controls / So easy a caveman can fix it!
« on: February 03, 2007, 03:58:26 PM »
The Cycle Stop Valve would eliminate your problem as long as everything is set up properly. What is your cut-in and cut-out pressure? How many gallons per minute are you pumping at full flow? What are you using for pressure tank(s)?
The way the CSV would solve your water hammer condition would be as follows:
1) Let's assume you are wanting a constant pressure of 60 psi. The valve would be adjusted to maintain 60 psi in your system.
2) Either adjust your current pressure switch to cut-in at 60 psi or install a 60/80 pressure switch. By doing this, the pump will start with a small flow which would eliminate hammer at cut-in.
3) At cut-out, the check valve in your system is only open a couple thousandth of an inch. Your flow at this point is only approximately 5 gpm. Because the flow is minimal at cut-out, the system gently shuts down and hammer is totally eliminated.
What is likely happening now is that you are starting at 50-60 gpm which creates a "shock-wave" in you lines. The same thing is happening at cut-out; you're going from 50-60 gpm to 0. This too creates a "shock-wave". The pressures created at cut-in and cut-out are extreme and you cannot see the pressure spikes on your pressure gauge.
We have eliminated this problem for many people. If you get back to me with the specifics requested above, I can tell you what size valve you would need and the pressure settings for both the valve and the pressure switch. Also let me know about the pressure tank configuration you are using.
Thanks,
Ron
The way the CSV would solve your water hammer condition would be as follows:
1) Let's assume you are wanting a constant pressure of 60 psi. The valve would be adjusted to maintain 60 psi in your system.
2) Either adjust your current pressure switch to cut-in at 60 psi or install a 60/80 pressure switch. By doing this, the pump will start with a small flow which would eliminate hammer at cut-in.
3) At cut-out, the check valve in your system is only open a couple thousandth of an inch. Your flow at this point is only approximately 5 gpm. Because the flow is minimal at cut-out, the system gently shuts down and hammer is totally eliminated.
What is likely happening now is that you are starting at 50-60 gpm which creates a "shock-wave" in you lines. The same thing is happening at cut-out; you're going from 50-60 gpm to 0. This too creates a "shock-wave". The pressures created at cut-in and cut-out are extreme and you cannot see the pressure spikes on your pressure gauge.
We have eliminated this problem for many people. If you get back to me with the specifics requested above, I can tell you what size valve you would need and the pressure settings for both the valve and the pressure switch. Also let me know about the pressure tank configuration you are using.
Thanks,
Ron
Pages: [1]