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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 15: Review exercise #2 (2 hours)
View the document Handout 15A: Review exercise

Session 15: Review exercise #2 (2 hours)

Time: 2 hours

Objectives: By the end of this session trainees will have demonstrated their ability to:

· determine maximum drive and delivery heads for a given ram;

· describe key interrelationships in a hydram;

· accurately describe at least 5 factors affecting efficiency in a hypothetical ram installation.

Overview: Work to date in the three areas described above has been primarily group work. This activity provides the opportunity to apply this information individually, and clarify any misunderstandings.

Materials: Handout 15A

TRAINERS NOTE:

Specifications for problem #1 need to be provided, using the charts from Sessions 9 and 10. Alternatively, participants can take actual measurements from the pipefitting rams they constructed, and solve the problem for those rams.

Procedures

Notes

1. Explain purpose of-session, resolve any hanging questions from previous session.

 

2. Distribute handout, instructing participants to solve problems individually.

Allow 30 minutes for this.

3. Participants to compare answers in groups of 24, coming to agreed upon solution(s).

30 min.

4. For each problem, ask for volunteers and provide group answers. Check with other groups for variation/difference. Discuss rationale for answers, and/or differences.

45-one hour

Handout 15A: Review exercise

1. What are the maximum recommended H & h in a 2" hydram where the impulse backing plate is thick, the impulse seat area is , has impulse valve bolts " in diameter, has a check valve backing plate " thick, and a check valve seat width of "?

Answer the following with a graph if you wish:

2. How does the amount of air in the accumulator effect "n"?

3. How does the h:H ratio effect "n"?

4. How does the frequency effect ''Qw''?

5. How does the snifter effect "q"?

6. Tomorrow you are going out to an existing hydram site where there is only 100 gpd being delivered, there is a reliable supply of 3 gpm and an h:H ratio of 10:1. The ram works consistently but the efficiency is so low that only ½ the water needed is being pumped. Do you feel 200 gpd can be pumped if the hydram and/or installation is corrected to improve the efficiency to a reasonable level? If yes, what are you going to look for as a possible reason for low efficiency? (At this point you know nothing else about the hydram or the manner in which it is installed) list as many factors as you can think of.