RAM PUMPS

How does one get water to a higher elevation without carrying it or using a hand pump? If there is a running stream or spring that flows briskly, it is possible. The answer is found in a Hydro Ram pump.

A ram pump requires hydraulic pressure to operate the pump (Not electricity!), so a drop or "head" is mandatory to make the pump work. The ram pump then uses the energy generated by the weight of the water to continuously pump a fraction of it uphill up to 10 times the "head" or fall feeding the pump. When the ram pump's poppet valve (the only moving part) is open, water flows downhill through the supply pipe to the pump and escapes out the open valve. That is waste water, and is utilized to generate the kinetic energy required to pump some of the water up the delivery pipe. As the water gains velocity in the supply, or drive pipe, it causes the poppet to snap shut, which causes hydraulic pressure to peak immediately (a "water hammer" effect), which forces some water through a check valve, and into the delivery pipe. This cycle repeats itself about once a second.

For those who have a mountain stream which could provide water to a cabin at a higher elevation, it is possible to add a reverse osmosis water purifier to the ram pump, so creek water can be delivered to a holding tank in pure condition.

The ideal situation is to use a ram pump in combination with a large storage tank situated at least 30 feet higher than the home. As the ram pump operates continuously, a smaller ram pump can fill a storage tank that can be drawn down during the day, for example. And assuming a pressure factor of 0.43 per foot of drop*, an elevation of 30 feet would deliver water to the ground at 13 PSI. That is certainly good enough to deliver water in quantity for most uses.

• *  Water weighs 62.4 pounds per cubic foot, or 62.4/144 pounds per in square per foot = 0.433 psi/foot.
  This is the weight of a column of water 1 inch * 1 inch * 1 foot.
  Another way to get this number is via metric equivalents:  1 cc of watter weighs 1 gm
  so 2.54 cm * 2.54 cm * 30.48 cm weighs 196.6 gm = 0.1966kg = 0.1966 * 2.2 lbs = 0.433 lbs
  Paul des Trois Maisons,  Toronto

Ram pumps have been around for a least a century. The older, bell shaped ram pumps manufactured by Skookum were made of cast steel, and lasted forever. They also cost a small fortune. Now there is an alternative, made from PVC, which will handle falls of 15 feet and lifts to 150 feet reliably. And, they are relatively inexpensive. If the fall is over 15 feet and the lift required is over 150 feet, then a more expensive steel ram pump is indicated.

The installation of a ram pump is not overly complicated, but it does require some study. You have to know how far downhill you will have to "pipe" the water before you get a sufficient "drop" or "fall" to operate the pump, how high and how far the water needs to be pumped, and how much water will be needed per 24 hour period. Once those basic factors are determined, you will then need to study the catalogue from Fleming Hydro-Ram Pumps very carefully to choose exactly which size pump will work for your individual situation.

 

For more information on ram pumps, contact 

 http://www.theramcompany.com/do4u.html

Fleming Hydro Ram Pumps

PO Box 698

Amherst, VA 24521

phone: 804-277-8511

OPERATION OF A HYDRO-RAM

Things to consider:
1. How far downhill you have to "pipe" the water before you get a sufficient "drop" or "fall" of  water to the pump;
2. How high you need to pump the water uphill;
3. How far you need to pump the water;
4. How much water you will need pumped uphill over a 24 hour period. How ram pumps work:

When the pump's poppet valve is open, water flows downhill through the supply pipe to the pump and escapes out the open valve. This is the waste water that is used to bring the water in the pipe into motion where it's kinetic energy can be utilized.

The water flowing in the pipe is quite heavy (water weighs about 8 pounds per gallon). As the water gains velocity in the supply pipe ("drive pipe"), it causes the poppet to snap shut. This sudden closure of the poppet causes the hydraulic pressure in the pipe to peak instantly (producing a "water hammer" effect) which forces the water though the pump's in-line check valve. Here the high pressure flow runs head-on into the back- pressure in the output line (the "delivery pipe"). Part of the water flow is forced up the air chamber, compressing the captive air and causing the water flow to lose most of its energy. As the peak water pressure subsides, the compressed air in the air chamber acts as a piston, pushing downward on the column of water. This causes the check valve to close and forces the water to seek the path of least resistance... up the delivery pipe.

When the check valve closes it causes a momentary pressure drop and a slight suction to occur on the supply side of the pump. This causes the poppet to reopen and the process continues repeating itself at a rate of about one cycle per second.

This cycling of the pump also produces a significant shock-induced pressure wave that rapidly travels back up the supply pipe. For optimum operation of the system (Le., the most water being pumped uphill), it is necessary to "tune" the supply pipe so the shock wave works for you rather than against you. The proper placement of a "stand pipe" is the primary method of tuning the pump's frequency.

The Fleming Hydro-Ram can lift water approximately 10 feet for each 1 foot of fall of the water from the water level at the drive pipe's intake point to the pump. For example, if you need to pump water 30 feet uphill, then you will require a minimum fall of 3 feet (a 10 to 1 ratio). However, in order to achieve a greater output of water at this lift, it is better to keep the fall-lift ratio as small as practicable. We can achieve a 5 to 1 ratio by increasing the fall of the water to 6 feet (6 x 5 = 30).

Where practicable, go for a greater fall of water to the pump in order to increase the output of the water pumped uphill.

If you require lifts of greater than 150 feet, we (Fleming) recommend using the steel 3" Fleming Hydro-Ram.

 

BACK

~~~~~~~~~~~~~~~~~~~