This series of questions and answers is designed to be used in
conjunction with the information provided in our main web page.
If
there are still things that remain unclear about our product please
do not hesitate to email us and put your questions in writing so that
me may answer them and expand this page to clarify as much as
possible.
The following are the most commonly asked questions but
they are not in any specific order of importance.
Q - What is lift?
A
- Lift is the vertical height between the surface of the water supply
being pumped and the intake of the pump.
It is sometimes known as
suction height and relates only to the vertical distance - not the
lineal measurement.
Q - What is "applied head" or
"head"? (as relating to water pumping)
A - Head
is the vertical distance between the pump and the discharge point of
the pumped water.
Applied head calculations may include an
allowance for pressure increases caused by the friction of the water
against the wall of the pipe through which it flows.
Our windmills
operate on a constant, slow flow basis and pipe friction is not a
significant feature in calculating pumping heads.
Q - How much wind is needed to pump the
amount you state in your brochure.
A - The wind speed
required to pump 500 gallons day depends on the vertical heights of
both the pickup (water supply level) to the pump and from the pump to
the discharge point, such as a reservoir.
With a lift
(suction) height of 1.8m (6ft) and a discharge, or head, height of
12.2m (40ft) a wind speed of 13.5 knots will give you 500 gallons in
a 24 hour day.
In the case of a 175ft applied head you would need
at least double that windspeed for the same output and this will also
depend on your lift height.
Q - What wind speed is required to
pump 500 gallons a day and if it will pump 175 ft, is that vertical
feet and at what wind speed is required for it to pump that kind of
distance.
A - Refer to the answer to the previous question.
Q
- Can your windmill be used to oxygenate a pond
or pool?
A - Our mill does not pump air but it can still be
used to aerate water by spraying or trickling the water back to the
supply.
The water has to come in contact with the air to become
aerated and the larger the area of water exposed the greater the
oxygen uptake.
For example a fine mist will take up more oxygen
than a steady stream of water.
Q - Why does our windmill need to be re-primed after it has stopped turning for a while?
A - Simple answer - because there is air in the inlet pipe leading from the water supply to the pump.
Either, air left in the inlet line which wasn't properly evacuated during the initial priming process, or there is an air leak in the inlet pipe or one of the joints in the inlet line.
During priming it is critical that all air in the line is completely evacuated.
Even a little air at the top of a "gooseneck" or hump can cause problems with getting a perfect prime and so it is best to have a steady uphill rise on the inlet pipe all the way to the pump whilst priming. Once the pipe is completely full and primed it may run over humps and hollows in the ground without causing problems.
The difficulty is compounded by the fact that, although the pump can be self-priming, the slow speed at which it operates in normal conditions is too low to allow it to be fully self-priming.
The most difficult problem to trace is if there is a faulty joint or of crack in the inlet line and so great care has to be taken to get all joints perfect and the use of new pipework is recommended.
Following the priming instructions provided with the windmill is of utmost importance.
Q - What minimum wind speed sustains pumping
capability?
A - Our windmills will pump water in wind
speeds as low as 1 - 2 knots.
Pump performance and energy
requirements are based on operating conditions and are governed by a
combination or factors including - vertical height of lift to the
pump - applied head, or vertical height the water is pumped to - pipe
size - and wind speed and density, in the case of a windmill.
Factors
such as ground contour and the proximity of buildings, trees, or
other obstructions which may cause turbulence can effect wind speeds
and effectiveness.
Q- What maximum wind
speed may cause damage to any operating parts?
A -
Turbulence and sudden wind direction changes are the major problems
for any windmill.
Strong, steady wind speeds of over 100 kph have
been handled by our windmills without problems.
Q - What
arrangement is there to stop the rotation of the blades?
A
- The fan can be turned out of the wind and then captured and tied
back to mast.
This may be necessary for maintenance or during
times when there is no pumping to be done.
Check
here for instructions on how this is done.
Q - Your
windmill does not have a tail or feathering device - why not?
A
- We do not fit a tail to our windmills because it is unnecessary to
do so.
It is an omnidirectional mill and will follow the wind as
required.
The perception that a windmill needs a tail to keep it
facing the wind is misconceived.
Designed correctly there is no
need for a tail to be used to capture the wind.
Tails are fitted
to most windmills, of this type, as a feathering device to turn them
out of the wind when wind speeds become too high for them to cope
with - our mill does not need to be feathered - it's blade design is
able to withstand very high wind speeds.
Q - Are
there recommendations for water filtering when fed from a pond or
natural water source?
A -Water quality and the necessity
for filtration or otherwise would be dependant on the water use.
We
do not make any recommendations in this regard although, from
experience, unless water quality is very poor and stock suffer from
drinking it, most stock water is used, unfiltered, direct from the
source.
The better the quality of the water the better it is for
stock.
Obviously the pump is made for pumping liquids - not solids
- and suspended solids in the water may cause wear in the pump and
this could suggest the use of some filtration system but in most
cases, if the intake pipe is suspended just below the surface of the
water, and does not sit in any mud on the bottom of the supply
source, there probably would not be any need for filtering the
water.
Q - What are the costs and
maintenance periods for normal wear and parts replacement?
A
- Maintenance costs are minimal and consist of regular greasing and
inspection every 3 - 4 weeks and replacement of a 50c reciprocating
o'ring every 6 - 12 months, dependent on water quality.
Q -
What are the recommendations for type of pipe
and fittings?
A - 25mm ID alkythene for the inlet pipe for
which we supply the fittings in the price of the windmill.
20mm ID
or bigger pipe of your choice for the outlet - we recommend 20mm ID
alkythene as the minimum.
Q - We have a
situation where the pump would be required to lift about 10 ft and
pump possibly/ideally 30 ft high, any problem?
A - No
problem at all so long as it is located where there is some wind.
Q
- What are screw anchors?
A - The
anchors are galvanised, heavy steel rods with an eye at one end and
an auger plate at the lower end and they are screwed into the ground
until the eye is almost level with the surface.
The guywires are
attached to these anchors to stay the windmill mast.
They are the
type used by the electricity industry to stay power poles - they do
not vibrate loose.
Q - How are the guy
wires kept tight?
A - Ratchet type fence wire tensioners
are used on the guy wires to keep them tight.
Q - What
wind speed is needed to make your windmills start pumping?
A
- Our windmills will operate in wind speed as low as 1 - 2 knots but
this is dependent on the lift and head you apply.
The higher you
lift the water to the pump and the greater the applied head ( height
to which the water is pushed ) the more energy, and therefore, the
higher the windspeed needed to achieve this.
With a lift of about
2 metres and a head of around 10 metres the windmill will operate in
that 1 - 2 knot wind range.
Q - Does
your windmill have a tail to feather it out of the wind?
A
- No.
Q - Why doesn't your windmill have a tail?
A
- The main requirement for a tail on a windmill is not to point it
into the wind but to be able to feather it out of the wind whenever
that may be needed whether it be for servicing or to reduce it's
speed in high winds to prevent over-revving and consequent
damage.
Ours is a 'down wind' design and, therefore, does not need
a tail to turn it into the wind as it will follow the wind from any
direction.
The drive train is very simple and robust without
complex gearing and is able to cope with wind speed changes without
possible problems caused by momentum in heavier designs and this
helps overcome the need for a feathering device, (tail) and thereby
increase it's simplicity, by the less dense design of it's fan and
it's ability to follow the wind.
Q - Is
there a govenor on your windmill?
A - There is no governor
- there is no need - increase the wind speed - increase the water
pumped.
Q - What sort of pump is used on
your windmills?
A - The pump is a proprietary design,
manufactured exclusively by us, and is a vertical mount, (due to
valve design) positive displacement type with a bore of 1.375"
(35mm) and stroke of 1.5" (38mm) and is made with a cast
gunmetal (bronze) body, stainless steel pump rod and valves, brass
valve bodies, leather main washer, engineering grade plastic gland
piston fitted with a nitrile o'ring seal. O'rings are used as static
seals for perfect sealing at joints which require simple and
effective resealing after any routine maintenance.
Q - Should I use sealing tape on the joints,
where there are o'ring seals?
A - NO!!!. It should just be
left at that categorical NO but to expand on that terse answer it
should be made clear that o'ring seals are just that – seals !!
They do NOT require any tape on threads or joints associated with the
seal.
Q - Should I use any tape or sealant on
threaded joints?
A – Thread sealants such as teflon
tapes and pastes, and hemp and other thread sealers are recommended
on thread joints to achieve good, air tight, seals. These sealers
should be used as per their manufacturers specifications for maximum
effect.
Q - It looks like, from your website, the
mast just sits on a concrete slab - does this slab just lay on a flat
piece of land or does this have to be buried into the ground a
little?
A - The mast does just sit on a concrete paving
slab, or similar, and is held by the three guywires. The piece of
concrete should be laid into any turf just to level it.
Q - What size concrete slab should be used
approx.?
A - The slab may be of any size sufficient to stop
the bottom of the mast pushing down into the ground but a standard
paving slab (as opposed to just a paving stone) of about a foot
square and two inches thick would be more than adequate for most
situations. A piece of ground treated, solid, timber would do just as
well.
Q - Are we correct is assuming that the pump
is located in the bottom of the mast?
A – The pump is
bolted to a plate, welded to the side of the mast, about 400mm up from
the base of the mast.
Q - Does the inlet pipe to the pump come in
through the side of the mast or up through the bottom of it?
A
- The inlet pipe enters the bottom of the pump and is external to the
mast.
Q - As the mast can be sited a little away
from the water supply can we assume that if it is up hill a little it
works on a suction lift basis Is it a problem to prime the pump if it
is on suction lift?
A - The pump is a standard, single
acting, displacement, plunger type, capable of suction lift up to a,
realistic, height of 25 feet above water level. It is very easy to
prime. The initial prime is done by hand operating the pump with a
handle which we supply. Once primed it should never need priming
again if the inlet pipework is installed properly - no leaks or
faulty joins!!
Q - What size
inlet pipe to you recommend on suction lift?
A
- We recommend low or medium density polyethylene pipe with a
25mm bore diameter for the inlet.
This type of agricutural pipe is
commonly known as alkythene, or LDPE, or MDPE.
LDPE would be the common recommendation with the MDPE possibly being used in where a lift of over about 5 metres is envisaged.
Q - How high up the mast does the outlet
pipe exit?
A - At about 450mm above the ground.
Both
inlet and outlet face downward normally. The outlet port has a tee
connection fitted to allow for a monitoring plug, tap, or gauge and
that fitting allows the outlet hose to be fitted to exit at right
angles to the mast or at any angle in the plane of the mast.
Q - What type of pipe fittings do we need to
connect to the inlet and outlet connections?
We supply the
inlet pipe fittings for the polyethylene pipe that we recommend.
The outlet pipe can be 20mm ID or larger and, once again,
we recommend standard agricultural polyethylene (alkythene) pipe.
Q - How long do you anticipate it would take
for two people to erect the windpump and to get it operational?
A
– A standard Ferguson windmill can be installed by one fully
competent person in about three hours or, with some help, in about
two hours.
The pipework and reticulation are not included in that
time as that is a variable that we cannot anticipate.
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