Cover Image
close this book A training manual in conducting a workshop in the design, construction, operation, maintenance and repair of hydrams
close this folder Session 13: Inter-relationships within the hydram (11-15 hours)
Open this folder and view contents Handout 13A: Exercises: Determining the effect of:
View the document Handout 13B: Typical hydram experiment set-up
View the document Handout 13C: Sample graphs

Session 13: Inter-relationships within the hydram (11-15 hours)

Time: 11-15 hours


The trainees will verify by experimentation the inter-relationships within a hydram including:


1) the effects of the h:H ratio on efficiency,


2) frequency on maximum h:H,


3) frequency on efficiency and q and Q


4) amount of air in accumulator on efficiency


5) drive pipe length on efficiency,


6) drive pipe diameter on efficiency,


7) snifter on efficiency, and


8) drive pipe material on efficiency


The trainees will describe the extent to which they can vary the factors that affect efficiency, and produce an acceptable amount of water.


A series of 8 experiments will be conducted by groups of 3-4 participants. The number of experiments each group conducts will depend on the size of the total group and the amount of time available. This activity is key in providing participants with experience and confidence in understanding and manipulating hydrams, and understanding the range of skills, materials, tools and equipment involved in a hydram project.


Handout 13, exercises 1-8 a water source with sufficient head to operate one or more hydrams, enough working hydrams for one to each group, drive pipes (all steel except one PVC)


pipe wrenches, stop watches or watches with a seconds function, buckets of known capacity, means of measuring drive head such as transit or sight level, pressure gauges, pressure relief valves



The time it should take for each series of experiments is as follows:

1) h:H ratio's effect on efficiency

2 hours

2) frequency's effect on maximum h:H

1½ hours

3) frequency's effect on efficiency, Q and q

2½ hours

4) volume of air in accumulator's effect on efficiency

2 hours

5) drive pipe length's effect on efficiency

4 hours

6) drive pipe diameter's effect on efficiency

2½ hours

7) snifter's effect on efficiency

1½ hours

8) drive pipe material's effect on efficiency

2 hours

Allow 1½ hours for the introduction to this session (procedure steps 1-4) and 2-3 hours for the groups to analyze their findings (step 6) and 3 hours for the group presentations and discussion.

The number of experimental stations available and the time an experiment actually takes, may mean that each group does 2-3 experiments each. It's a good idea to have more than one group run an experiment to verify results.





Describe the objectives of this session.



Divide the trainees into groups of 3-4, making sure each group contains. a cross-section of technical abilities.

Each group of 3-4 should possess a range of technical abilities


Give each group the task and procedure sheets for the experiments which you want them to perform.



Assign groups to work spaces and ask them to take 15 minutes to decide how they will work together,

Each group will need to assign responsibility for timing the experiment, measuring Qw , maintaining pressure gauge recording data, reporting out, analyzing data.


- get clear about procedures, task,


- make assignments for presentation, write-up.



The groups follow the procedures on the task and procedure sheets.

The trainers must be available to participants as necessary to respond to questions, ensure that procedures and conclusions are clear and on target. Trainer should encourage groups to review their work at the end of the first block of work time.


After the experiments are finished, the trainees meet with their groups for 2-3 hours to analyze the data collected, to plot the results of their experiments onto the graphs provided in the handout (all except for the snifter experiment which needs no graph), and to define the generalizations that can be made and the applications.

See Guide to Users for setting up experimental stands.


A representative from each group presents the task, procedure, results, generalizations, and applications for the experiments performed.



A discussion follows about what has been learned and what wasn't learned that perhaps should have been learned.



Ask participants to describe how start up of ram might be different at actual installation vs. this experimental arrangement.