Pumps

Archive for September, 2009

Your swimming pool or spa pump has pumped its last gallon of water and it looks like it’s time to purchase a new one. Since more horsepower is always better, it certainly would be a good idea to purchase a more powerful pump. Wrong! Use caution when deciding to install a new pump if you are going to increase the horsepower of the unit. First, review the gallon per minute flow chart of the pump you are considering. Most equipment manufactures provide flow specifications of each one they manufacture. How much water flow does the unit you are considering produce? Next, review your existing filter characteristics, again, most manufactures provide flow rates for their filter models. What is the maximum amount of water flow in gallons per minute that your filter will allow? Make sure that you new pump will not exceed the allowable filter flow, as damage can be done to the filter housing and to the filter internals. Also keep in mind that the pool and or spa piping has been designed with its own flow characteristics. Trying to put to much flow through the piping can also cause damage to your plumbing system (Pressure Side). The suction side piping has also been designed to accept a certain amount of flow. Trying to “pull” more water through a piping system than what the system has been designed for will also cause issues and problems. If a larger horsepower pump can not receive all the water flow that is required for it to function properly, the pump will most likely cavitate, trying to seek and find enough water flow to allow it to operate correctly.

As you do you research and make your decisions about your new pump, it will become clear that your existing horsepower pump might be the best size for your swimming pool and or spa system. Also keep in minds that if you are replacing a very old inefficient pump with a new high efficient unit, check the water flow characteristics of the newer pump. Many new high efficient pumps push more water than the older style pumps. Larger horsepower pumps also require additional electrical energy thus resulting in higher electrical costs. Many times it is best to consult with a swimming pool professional that can ask questions about your pool system and help you determine the best style and type of pump which will operate best in your situation. Keep the water flowing at just the right flow rate and have an enjoyable crystal blue pool and spa today.

Ron Burr
http://www.articlesbase.com/home-and-family-articles/correct-sizing-techniques-for-swimming-pool-and-spa-pumps-692094.html

I think you use the built up pressure immediately when you turn on the faucet…and there is a hiccup when the pump kicks on and you change from pressurized reserve to pumped water.

Anytime water is used, the pump gauge keeps going from 60psi down to 40psi, then it goes back to 60. This keeps happening for as long as the water is being used. At the same time the water pressure also pulsates along with the gauge changes. The system is nine years old. I also noticed that there is a valveon top of the tank. I pressed in the neddle on the valve and water squirted out. I am afraid that I’m going to burn out my well pump. Do I have a problem? What can I do?

the baldder in you pressure tank has ruptured.
when you press the needle on the valve air should come out not water.
you well pump should be ok if you get the tank replaced soon.
install a new bladder tank. call a plumber if you cant do it yourself.

i have a drilled well 8 inch diameter casing, it is 35 feet deep. what is the maximum lift capacity of my shallow well pump, it is a goulds 1/2 hp jet pump

a 1/2 hp jet pump will lift water 50 ft as long as you have two pipes in the well with the injector assembly within one foot of the bottom..with one pipe and the injector at the pump, no matter what hp the pump will only lift water 35 feet…you shouldnt have no problems with this pump in either case as goulds pumps are a quality pump…

Gauge Pressure Question?
Not having much luck at all with this one.

Water is to be pumped through a 10.6 cm diameter pipe over a distance of 285 m. The far end of the pipe is 21.1 m above the pump and is at normal atmospheric pressure. What gauge pressure must the pump develop for there to be any flow at all?

If it is a straight with no friction, then it is true that the pump will pump

at 21.1 m head that is 30.003 571 353 pound/square inch pressure.

[21.1 meter of head = 2.109 459 825 9 kilogram-force/square

centimeter ]

But in practical, you have to consider head loss due to friction through

the piping network.

Head loss due to friction

=friction factor x length of pipe x velocity^2 ] / [2 x g x diameter of the pipe]

Here, you have to consider the equivalent length of pipe , that is considering all pipe fittings [ elbow,tee,valves,reducers, etc ]

Some of the formula you may find useful :

1.Pressure= rho* g * head

Pressure = 1000 * 9.81 * 21.1 [ kg/m^3 * m/sec^2 * m]

Pressure = 206991 kg sec^(-2) m^(-1)

Pressure = 206991 pascal

Pressure = 206 991 newton/square meter

Pressure = 2.110 720 786 4 kilogram-force/square centimeter

2.Flow = Area * Velocity

I wanted to make an indoor manmade river for an art project. the water at one end would ideally be sent to beginning to give the impression of a constant flow, ie. a real river. would it be possible to do this by attaching a submersible pump to one end of the river, and tracing it back to the beginning?…or would the horizontal path cause problems?

A submersible pump should work fine. You will just have to tinker a bit with your head flow, as you don’t want a gusher pointing up to the ceiling. Using various reducers to drop the size of the outflow, or putting a rock or something to flatten the water stream, should take care of that. You’ll want to make sure that you get a pump that has enough power to push the water back up to the head of your stream, too.

This sounds like a really intriguing project. I’d like to see it when it’s done!

Good luck - hope this helps.

I have a 55 gallon freshwater tank with a sump that has an overflow rated for 600 gallons per hour. I want to get a return pump that does 1128 gallons per hour. Will the pump be too powerful/ pump water too fast or will it be ok? My tank is 4 feet from the sump.

Please Help

You seem to have a very good understanding of pumps and ‘head pressure’ or ‘back pressure’. The pump you’re selecting will be critical in determining if 1128 gph is ok or too much. Pumps are not only rated by gph but also by whether or not they are pressure rated or flow (circulation) rated.

A pressure rated pump will pump more water to higher heights or to tanks that have more plumbing fittings than a system that has less vertical height to pump to with less plumbing fittings.

A flow (circulation) rated pump is designed to pump water at basically zero head pressure, such as a powerhead in a tank, pump for a protein skimmer, pump for a media reactor, etc.

Here’s a great site for pumps. I’ve used them MANY times with great success.

i have a shallow well pump(goulds 1/2 hp) i have replaced all my water lines in the house with cpvc 1/2". all faucets, toilets etc have been replaced recently. i do not have enough pressure in my up stairs shower/tub. my pump pressure is set at 45 lbs right now. i am wondering what the safest high pressure i can set my pump to.

40 psi on and 60 psi off. That will work fine. You can go higher but I wouldn’t recommend it for your pumps sake.

I am looking for a pressure pump(washer) that generates 1500-5000 psi applying 12V DC battery. How many batteries required ?
Can I buy such pumps in the market ? please give more information on it.

My pressure washer has a 5 horsepower motor and creates about 200 psi. The short answer is that car starter motors create 5 to 10 hp for a short while but get hot fast. One battery will do the job for a very short while. The easier way is to use an electric washer, convert the 12 vdc to 120vAC with an inverter and wash away. The amount of batteries will depend on how long you want to operate at high pressure. The more the better. Can you buy such a pump, sure, convert a small home electric unit. Another good source for this stuff is West Marine, check their website and they have a great tech staff and no I don’t work there.

running water supply here only lasts for about 3 hrs in the ,morning. i have a 80 litre storage bucket but i dont like to lift the mug for every use when tap water supply is not there. but i have an old small submersible pump. i think i can control its speed with a regulator. but the wires etc would be dipped inside the bucket…..who knows when insulation will fail…….any better safety solution.

What country are you in ?
No the old sump pump will be contaminated
store it in gal jugs, or get a NEW sump pump or a pond pump