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close this book A training manual in conducting a workshop in the design, construction, operation, maintenance and repair of hydrams
close this folder Session 11: Hydram component design criteria (1-1½ hours)
View the document Handout 11A: Typical impulse valve
View the document Handout 11B: Typical check valves
View the document Handout 11C: Typical snifters

Session 11: Hydram component design criteria (1-1½ hours)

Time: 1-1½ hours


By the end of this session, trainees shall be able to:


· describe how each hydram component is or can be made, and the advantages and disadvantages of each design, including longevity, serviceability, reliability;


· describe how the configuration of the components affect their function and the overall efficiency of the hydram; and


· select hydram component appropriate for their sites.


Trainees will examine advantages and disadvantages of manufactured and fabricated ram components, and configurations. Combining this information with information about locally available materials and skills, they will determine ram construction that is most applicable.


· flipchart/chalkboard


· slides, slide projector


· actual parts, as available (see trainer note)


The handouts for this session will be very helpful in presenting the information on the individual components but having the actual components available would greatly increase the effectiveness of this session. If in the country that the trainees will be working there is one brand or type of hydram predominantly being used, it would be most advantageous to have a hydram of that type at the training site. The types and brands of the components the trainees will most likely encounter are the ones that the greatest amount of attention should be given to.





Review the purpose of this activity.



Ask the trainees to list the components of the hydram and write them on the flipchart/board. It should include the drive pipe, impulse valve, snifter, check valve, accumulator and delivery pipe.



Distribute Handout 11A.



Using handout 11A, ask the trainees to point out any problems or advantages of each of the components. Fill in any information the trainees leave out.

Slides can be used very effectively as well.


Repeat steps 3 and 4 using handouts 11B and 11C.



Once the trainees have a good understanding of the components, discuss with them all the possible configurations of the components and how the placement of a particular component affects the overall efficiency of a hydram. The configuration possibilities should at least include:


- the location of the impulse valve (either before or after the accumulator);


- the angle of the impulse valve (on the top, side, or bottom of the hydram);


- the placement of the snifter and how it affects its function;


- the possibility of more than one impulse valve (as in the case of larger Blake Hydrams); and


- the angle of the check valve (either vertical, horizontal, or up-side down),


- the size and shape of the accumulator, and


- how the configuration affects the water's path.



Make a transition to Session 12, indicating that this information will also be used to consider choices among hydram designs.