Frequently Asked Questions

How do I prime my jet pump?

The objective when priming a pump is to eliminate all air from pump and suction lines.

Step 1.  Remove plug from top of pump.
Step 2.  Fill pump and suction hose(s) to the top with water.
Step 3.  Replace plug loosely (to allow any remaining air an exit) and start pump. Air and water will escape from priming hole. When water starts to forcefully spray from loose plug, the pump is primed. Tighten plug (with teflon tape on threads).

If pump does not pump after thirty to forty-five seconds, turn off pump. Repeat above steps, this may have to be done a few times until all air is out of all the suction pipes and pump rises in pressure.

Please note: Do not run pump too long without water, as you may damage the seal. If after repeated attempts the pump still refuses to prime, check suction connections for leaks, you may be drawing air.

How do I adjust my irrigation pressure system?
  1. Prime pump as per “Priming a Jet Pump” instructions
  2. Open irrigation valve(s) & run sprinkler(s)
  3. If pump catches up to flow & reaches pressure switch shut-off pressure, tighten nut on large spring on pressure switch until pump runs continuously
  4. Close valve(s)
  5. Ensure pump pressure climbs sufficiently to shut off pump
  6. Partially open valve & allow pressure to drop until pump starts ** make note of pressure reading on gauge at which this occurs **
  7. Turn off power & allow pressure to fall to 0 PSI
  8. Using tire gauge, measure air pressure in tank & adjust by adding or removing air until a reading of 2 – 5 PSI less than pressure noted above **
  9. Reconnect power & allow pump to rise in pressure until it shuts off, open irrigation system & ensure pump runs continuously
How can I adjust the pressure of my system?

Standard Pressure Switch – is factory pre-set. Common factory settings are 20 – 40PSI, 30 – 50PSI & 40 – 60PSI. These switches respond at two pressure settings:

  • the “cut-in” or motor on setting (eg. 30PSI)
  • the “cut-out” or motor off setting (eg. 50PSI)

These are adjustable settings, the larger spring moving both the cut-in & cut-out together leaving the same differential. If the switch has a second, smaller spring it adjusts the differential. If the original setting has been entirely lost, the sequence of adjustment must be:

  • the large spring first to set the cut-in on a falling pressure
  • then the small spring to set the cut-out
  • turn nut clockwise to raise pressure, counterclockwise to lower pressure in both cases

Loss of Prime Pressure Switch – is similar to a standard pressure switch & is adjusted in the same manner but also includes an additional non-adjustable low pressure cut-out setting. If the system pressure falls approximately 10PSI below the cut-in (pump ON) pressure, the switch points will open & shut off the pump. In other words, if the pump has lost prime when the switch calls for it to start, the pressure continues to fall rather than rise. The switch will then shut off the pump.

Loss of prime pressure switches MUST BE MANUALLY STARTED. They do not automatically reset & incorporate a lever that must be turned upwards approximately 1/4” & held until the pressure rises above low pressure cut-out level. It can then be released & the switch will continue to function in a normal manner until a low pressure is detected again. It is necessary to follow this procedure upon first start-up as well.

What is a cycle?
A cycle refers to the pump run time. A cycle begins when the pump starts and is completed when the pump stops. Pump starts and stops are determined by the pressure switch settings on the system. Common pressure settings are 20/40, 30/50 and 40/60 PSI. This means the pump will cut-in (start) when the water pressure inside the tank reaches the lower setting (ie. 20, 30 or 40) and will cut-out (stop) when the higher setting is reached (ie. 40, 50 or 60).
How does a pressure switch control the pump and tank?
The pressure switch communicates with the tank and pump. The pressure switch monitors the pressure inside the tank and activates the pump when cut-in (start) and cut-out (stop) pressures are reached inside the tank.

 

What is drawdown?
Drawdown refers to the amount of water that evacuates the tank before the pressure switch will activate the pump. Drawdown is affected by the pump, the size of the tank and the pressure settings that govern your water system.
What is pre-charge pressure?
Pre-charge pressure refers to the amount of air in PSI that is put into a tank prior to installation, usually at the factory. Most tanks are provided with a 28 PSI pre-charge (38 PSI on larger models). The pre-charge is the “spring” that stores the water pressure made by the pump. As the diaphragm fills with water, it compresses the pre-charge. The pump will continue to propel water into the tank until the water pressure reaches the switch cut-out (stop) set point. The pre-charge can be adjusted on site for different switch operating pressure ranges.

 

How much pressure (pre-charge) should be in my tank?
Your tank should be pressurized 2 – 5 PSI less than the cut-in (start) pressure setting of the switch. For example, if the switch is set to start the pump at 30 PSI and shut off at 50 PSI, then your cut-in is 30 PSI and your tank should have a pre-charge of 25 – 28 PSI. If you have a “soft start” submersible pump the pre-charge should be 10 PSI less than the cut-in.
How do I check or change the pre-charge air pressure in my pressure tank?
Make note of the operating start pressure or desired start pressure before proceeding. Run the pump through a cycle if necessary by opening a cold water faucet. To check pre-charge, you must completely drain the tank. To do this, shut the power off to the pump, close the main shut off valve to the house plumbing, attach a hose to the hose bib at the bottom of the tank, run the hose to a floor drain, sump pit or sink drain and open (turn on) the hose bib. If there is no hose bib at the tank, leave the main valve open and turn on the nearest cold water faucet. This will drain the tank and not allow it to refill. Once the water stops flowing, the pump pressure gauge should read 0 PSI. If the tank is completely drained and the gauge does not read 0 PSI, the gauge is faulty and should be replaced while the system is shut down. On the top of the tank you will find an air valve (similar to the air valve on your tires) – use a tire pressure gauge to check the air pressure and adjust up or down as required. To adjust down simply let air out through the valve stem; to increase, add air through the valve stem with an air pump or compressor. Check with tire pressure gauge until desired set point is reached.
How do I know when my tank needs to be replaced?
If it is a galvanized tank on a domestic water system, it is probably a good idea to replace it now; a captive air tank will be better for the pump and the system. Any signs of major rusting would also indicate it is time for replacement. Small areas of surface rust may not necessarily mean it is time to replace but should be monitored for future signs of worsening. Any scratches on a painted steel tank should be touched up with rust paint. A tank that is undersized for the pump or household requirements should be upgraded for one that allows for a 1 – 2 minute pump cycle. This would be a minimum preferred size to maximize motor life. A tank that has a failed bladder or diaphragm should be replaced immediately to prevent premature switch or motor failure.
How do I determine if the diaphragm has failed?
If it is in the early stages, it may be hard to determine. You may notice that not as much water is being used between pump cycles as when the tank was new. If it has progressed to a waterlogged condition, the pump will cycle rapidly when a tap is running; sometimes when the air valve on top of the tank is depressed water will leak out; by tapping the side of the tank the top 2/3 would sound full whereas it should sound hollow; by draining the tank and gently rocking it, if it is connected with flexible hose, it would seem heavy or you may hear water sloshing around. The reason the water doesn’t empty the tank after it has entered the air chamber is because it is forced under pressure, often through a pinhole, over a period of time. Even though the water side of the tank has been drained the air side will remain full, thus waterlogged – that is, full of water with no air remaining.
What happens to the tank when the diaphragm fails?
Water leaks into the air chamber of the tank causing the tank to become waterlogged. Depending on the severity of the rupture it may be a pinhole or something more significant. The diaphragm is a wearing part as it is constantly flexing with the system pressure changes. A tank that has a failed diaphragm should be replaced immediately to prevent premature switch or motor failure.
Why is my pump starting when no water is being used? Sometimes at night I can hear my pump start OR I happened to be in the basement and the pump came on.

There are a number of different reasons this could be happening. Two possible explanations are:

1. It could be a water treatment device, such as a water softener, that is going through its backwash cycle and demanding water. If it is happening when you’re not expecting it, check the timer on the unit to make sure it is set properly. The timer may be off due to a recent power outage or time change.

2. There may be a leak. Check around the pressure tank, jet pump (if installed) and fittings for signs of water. Be sure to rule out condensation on a hot day. A leak could occur through a faulty backflow preventer, such as a foot valve or check valve, a split in the pipe, a corroded fitting or a plumbing fixture. Determine how much time passes from the pump shutting off to when it starts again. Depending on the size of the pressure tank you’ll know roughly how much water is being “lost” in this time. For example, a 20 gallon pressure tank will hold 4 – 6 gallons of water under pressure, depending on the pressure switch settings. If the pump is cycling every minute, that would be a significant amount of water and would be noticed if leaking around the tank or pump area. It is likely to be a backflow preventer, pipe or corroded fitting problem. If the pump is cycling once every 12 hours, that is a much slower leak and less noticeable. Leaks do not repair themselves. A slow leak will become worse over time and likely more noticeable. To determine if the leak is on the house side (plumbing fixture) or the well side (backflow preventer, pipe, fitting) you must shut off the main valve for the house plumbing, make note of the pressure gauge reading and do not use any water for the length of time that you noticed the pump starting on its own. This test is dependent on a properly functioning pressure gauge. If, after that time, you notice the gauge reading has not dropped and the pump has not come on, then there is a plumbing fixture leaking somewhere in the house; investigate or call a plumber for service. If the gauge reading continues to drop or the pump starts, the problem is on the well side. A split pipe between the house and the well will oftentimes (not always) be noticeable at ground surface as water might puddle on the lawn or make the ground soggy. Walk between the house and the well looking for signs, not to be done on a rainy day. If that checks out the problem might be in the well.

These are just guidelines, if you’re unsure please call us for service.

General Information

Jet Pumps

A jet pump is a centrifugal pump equipped with a jet assembly, which consists of a nozzle and venturi that recirculates water back to the impeller and boosts the pump’s capacity to make pressure. The jet assembly is a pump in its own right and can thus be mounted on or in the pump as a shallow well system for suction lifts of up to 25 vertical feet, or remotely mounted via two hoses as a deep well system when lift is beyond 25 feet.

 

Considerations When Choosing a Jet Pump

Jet pumps are typically categorized as domestic or cottage duty. Domestic duty pumps are designed to pump well water which is usually colder than lake or river water and thus will cause condensation or sweating on the pump casing in a humid environment. To prevent this wetness from reaching the front motor bearing, domestic duty pumps have an additional casting creating an air space between pump and motor. Cottage duty pumps are not provided with this extra casting, leaving the motor bearing in close proximity to humidity. Generally speaking, the overall quality of domestic pumps is superior to most cottage duty pumps in a number of other respects, such as quality of motor and size of casing. A higher quality motor results in quieter operation and longer life, and larger casings make the pump considerably easier to prime.

gallery---06-well-rite-pressure-tanks 1300440Pressure Tanks

The role of the pressure tank in a domestic water system is an important one. Apart from ensuring that there is minimum fluctuation in your tap pressure between pump off and on, it ensures that the pump motor does not overheat and wear prematurely due to over-frequent starting. The bulk of the heat generated in a motor occurs upon starting, and a motor asked to start more than once a minute will get very hot indeed. The motor manufacturers of both standard and submersible motors insist that when a motor is asked to start, it should run for at least a minute, two minutes preferred, as it takes that long for the fan to cool down the start winding or, in the case of a submersible motor, for cold water to flow past and cool it. Therefore, a pump capable of pumping 10 gallons per minute should be fitted to a tank that can hold 10-20 gallons under pressure. This does not mean you will need a 10-20 gallon tank. The bulk of the swept volume of a tank is taken up by air, which acts as the “spring” or “cushion” to store the water pressure made by the pump.

Years ago, the most common tanks were galvanized or glass-lined and had no separation between air and water. Because air dissolves in water, these tanks required constant draining and air pumping to prevent them from becoming waterlogged – that is, full of water with no air remaining. Water is virtually incompressible and a waterlogged tank will evacuate perhaps an ounce of water between 30 and 50 PSI. The result is a pump that cycles rapidly or “telegraphs,” leading to premature motor failure. Some attempts were made to solve this problem by inserting a round styrofoam float in the tank to act as a barrier between the air and water. This was successful in slowing down the dissolution of the air but did not eliminate the problem. It also presented another problem when the styrofoam eventually started to breakdown, plugging the plumbing lines and fixtures. Air volume controls were also introduced; however these required regular maintenance and seldom worked effectively for long periods.

A more satisfactory solution was achieved with the invention of the captive air tank. These tanks have separate chambers for the air and water. The result is a tank that can be accurately charged with the correct amount of air pressure for the system operating pressure and can hold that charge indefinitely. With a quality captive air tank, the water does not come into contact with any metal parts other than the stainless steel inlet connection. Among the features of a quality captive air tank are a condensation reducing design and a thicker, more supple controlled action double diaphragm for maximum life. A captive air tank has the additional benefit of being more efficient than a galvanized or glass-lined tank. For instance, a 42 gallon galvanized tank will have approximately 5 gallons of water available to use under pressure, also referred to as the “drawdown.” In comparison, a captive air tank of 20 gallons swept volume will also have a drawdown of approximately 5 gallons. Captive air tanks are available in a range of sizes to ensure proper motor protection.

Sump Pumps

sump-pump 1210587There are two types of domestic sump pumps commonly in use today, column and submersible.

The column type has its motor mounted on top of a long, hollow column with the pump shaft running within, connecting the motor to the pump below. Years ago, these pumps were the only type available and were generally very well made with heavy metal parts of superior quality. Today, most column pumps have a standard (non-stainless) steel or hollow aluminum shaft running through a steel column, and are prone to corrosion. The pump shaft is supported at the lower end by a bronze bushing that is lubricated by the water itself. This arrangement is subject to wear if there is any sand or silt in the pit and can also seize if the pump is idle for extended periods of time. With a heavy motor mounted on top and the pump at the bottom usually constructed of plastic, it makes the unit very top heavy and it can topple easily if not properly supported and installed on a firm, level base. The primary advantage of these pumps is they are relatively inexpensive as they are generally sold for less than $100.00. Better quality column pumps are available, fitted with plastic or even brass columns and, more importantly, stainless steel shafts; however, their cost will be higher, surpassing that of a submersible pump.

Submersible pumps are commonly available in plastic, cast iron or stainless steel construction. Like column pumps, plastic submersibles are of inferior quality. Balancing quality and price makes cast iron pumps a good choice but not all are equal. A quality submersible pump is considered to be a heavier duty alternative to the column pump. It takes advantage of the great advances made in the efficient sealing of rotating shafts, allowing the motor assembly to be close coupled to the pump and to be submersed with it in the sump water. The ball bearings in these pumps are in an oil bath and tend to last considerably longer than the water-lubricated bushings of a column pump. The cast iron housing will better dissipate the heat generated by the motor to the sump water and has a durable epoxy powder- coated finish for excellent corrosion resistance. The better submersible pump will also have a copper-wound motor rather than less resistant aluminum, and all fasteners will be non-corrosive stainless steel. A submersible pump will run considerably more quietly than a column pump and in some cases, more efficiently, which reduces electrical consumption.

sump-performance 1210586The height a sump pump must raise the water has a direct effect on its performance, as does the friction in the piping through which it discharges. You will notice in the performance curve shown to the right, as height (total head) increases, performance (GPM) decreases. Total head is the measurement of resistance to flow and is a combination of the height and friction the pump must overcome. For example, at 10 feet total head, this pump will discharge approximately 37 GPM and the same pump at 15 feet total head will discharge approximately 26 GPM. The shut-off head, meaning the height at which the pump will discharge 0 GPM, is approximately 22 feet. They are available in a wide range of sizes, starting at 1/4HP, to meet specific height or flow requirements. The higher the horsepower rating, the higher the gallon per minute output that is discharged and the total head that can be achieved.

Glossary

Cavitation – is the formation and implosion of cavities (gas bubbles) in a liquid when the absolute pressure reaches the vapour pressure and the liquid vaporizes. When the bubbles collapse they typically cause very strong local shock waves in the liquid, which may be  audible and may cause severe, permanent damage to the pump components resulting in poor performance.
Centrifugal Pump – spins water by means of an impeller creating a vacuum in the center pushing water out with centrifugal force which is redirected by the volute.
Flow Rate – is the volume of fluid which passes through a given surface per unit time commonly expressed as gallons per hour (GPH), gallons per minute (GPM) or litres per second (L/s)
Friction Head – the pressure expressed in lbs./sq. in. (PSI) or feet of liquid needed to overcome the resistance to flow in the pipe and fittings.
Friction Loss – refers to that portion of pressure lost by fluids while moving through a pipe, hose, or other limited space.
Impeller – a rotating component of a centrifugal pump which transfers energy from the motor that drives the pump to the fluid being pumped by accelerating the fluid outwards from the center of rotation.
Mechanical Seal – a spring-loaded device that forms a seal between the pump and motor or engine to prevent leakage.
Net Positive Suction Head (NPSH) – the difference between suction pressure and vapour pressure.
Net Positive Suction Head Available (NPSHA) – the amount of liquid pressure available to the pump intake after pipe friction losses and head pressures have been taken into account.
Net Positive Suction Head Required (NPSHR) – the amount of liquid pressure required at the intake port of a pre-designed and manufactured pump.
NPT – refers to National Pipe Thread which is a U.S. standard for tapered threads used on threaded pipes and fittings.
Piston (Reciprocating) Pump – a type of positive displacement pump where a motor moves a piston in a cylinder, pulling and trapping the fluid in a chamber and discharging it on the opposite stroke. Can be self-priming in many applications.
Pitless Adapter – a device, usually brass, designed to replace the need for well pits that is attached to the well casing below the frost line to connect the in-well water line to the buried water line leading to the point of use. It allows the pipe to pass horizontally through the casing so that no pipe is exposed above ground where it could freeze thus allowing year round access to the pump and components in the well from the surface.
Pressure Head – the pressure in feet of liquid in a tank or vessel on the suction or discharge side of a pump.
Priming – the action of starting the flow in a pump or siphon. With a centrifugal pump, this involves filling the pump casing and suction pipe with water.
Recovery Rate – rate at which groundwater refills the casing after the level is drawn down. This is the term used to specify the production rate of the well.
Shut-off Head – the point at which the pump will not push water past the listed feet in a vertical column. As a general rule, a long horizontal run (ie. over 50’) then friction loss becomes a factor.
Static Discharge Head – the vertical distance from the center line of the pump to the surface level of the discharge liquid.
Static Suction Head – the vertical distance from the center line of the pump up to the liquid surface of the suction supply.
Static Suction Lift – the vertical distance from the center line of the pump down to the surface of the suction supply liquid.
Static Water Level – the water level in the well prior to pumping usually measured from ground surface, may be subject to seasonal changes or lowering due to depletion.
Submersible Well Pump – long and narrow, these pumps are designed to fit into well casings below the water level. Consisting of multi-stages of impellers and diffusers coupled to a submersible electric motor this type of pump can provide better flow and pressure than a centrifugal pump and last longer in most applications.
Suction Head – exists when the source of supply is above the center line of pump, also referred as Flooded Suction.
Suction Lift – exists when the source of supply is below the center line of pump.
Total Dynamic Discharge Head – the static discharge head plus velocity head at the pump discharge flange plus total friction head in the discharge system.
Total Dynamic Head (TDH) – the total dynamic discharge head plus dynamic suction lift (when suction supply below pump) or minus total dynamic suction head (when suction supply above pump).
Total Dynamic Suction Head – the static suction head plus velocity head at the suction flange minus total friction head in the suction line.
Total Dynamic Suction Lift – the static suction lift minus velocity head at the suction flange plus total friction head in the suction line.
Vapour Pressure – the pressure absolute at which a liquid, at a given temperature, starts to boil or flash to a gas.
Velocity Head – a measurement of the amount of energy in water due to its velocity or motion.
Volute – the casing surrounding the impeller in a centrifugal pump that collects the liquid discharged from the impeller.

 

Formulas

NOTE: The formulas which appear below should be used for estimating purposes only.
Meters = Feet x 0.3048
Feet = Meters x 3.281
Litres = US Gallons x 3.785
Litres = Cubic feet x 28.32
US Gallons = Liters x 0.2642
US Gallons = Imperial Gallons x 1.20095
Cubic Meters = Cubic Feet x 0.0283

 

Cubic Feet = Cubic Meters x 35.31

PSI = Feet of water x 0.4335

Feet of water = PSI x 2.307
Gallons = Cubic feet x 7.48052
Gallons/min = Cubic feet/sec x 448.831
Pounds of water = US Gallons of Water x 8.345
Kilowatts = Horsepower x 0.7457

 

AC/DC FORMULAS
To find
Direct Current
AC / 1 phase
115V or 120V
AC / 1 phase
208, 230 or 240V
AC 3 phase
All Voltages
Amps when Horsepower is known
HP x 746
E x Eff
HP x 746
E x Eff x PF
HP x 746
E x Eff x PF
HP x 746
1.73 x E x Eff x PF
Amps when Kilowatts
is known
kW x 1000
E
kW x 1000
E x PF
kW x 1000
E x PF
kW x 1000
1.73 x E x PF
Amps when kVA
is known
 
kVA x 1000
E
kVA x 1000
E
kVA x 1000
1.73 x E
Kilowatts
I x E
1000
I x E x PF
1000
I x E x PF
1000
I x E x 1.73 x PF
1000
Kilovolt – Amps
 
I x E
1000
I x E
1000
I x E x 1.73
1000
Horsepower (output)
I x E x Eff
746
I x E x Eff x PF
746
I x E x Eff x PF
746
I x E x Eff x 1.73 x PF
746
E = Voltage  /  I = Amps  /  W = Watts  /  PF = Power Factor  /  Eff = Efficiency  /  HP = Horsepower

 

Storage of water per foot of pipe
= Inside Diameter squared (ID2) ÷ 24.5  eg. 1.252 ÷ 24.5 = .064 gallons per foot

PIPE SIZE I.D.
VOLUME IN GALLONS PER FOOT
.75”
.023
1”
.041
1.25”
.064
1.5”
.092
2”
.163
3”
.367
4”
.653
5”
1.02
6”
1.469
6.25”
1.594
8”
2.612
10”
4.082
12”
5.878

 

Ohm’s Law:

ohms-law 1210241