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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 9: Hydram design theory and parameters (2 hours)
View the document Handout 10B: Thickness of the impulse valve plate - inches
View the document Handout 10B: Thickness of the impulse valve plate - metric
View the document Handout 10C: Impulse valve steel backing
View the document Handout 10C: Impulse valve steel backing - metric
View the document Handout 10D: Impulse valve seat width - inches
View the document Handout 10D: Impulse valve seat width - metric
View the document Handout 10E: Check valve backing thickness - inches
View the document Handout 10E: Check valve backing thickness - metric
View the document Handout 10F: Check valve seat width - inches
View the document Handout 10F: Check valve seat width - metric
View the document Handout 9A-1: Welded hydram: side view
View the document Handout 9A-2: Welded hydram: exploded view
View the document Handout 9A-3: Welded hydram: impulse cavity exploded view
View the document Handout 9A-4: Welded hydram: accumulator: exploded view
View the document Handout 9A-5: Welded hydram 20' drive head dimensions
View the document Handout 9A-7: Welded hydram 20' drive head dimensions

Session 9: Hydram design theory and parameters (2 hours)

Time: 2 hours

OBJECTIVES:

• to examine the basic design guidelines for hydrams;

• to apply the guidelines to pipefitting, welded and/or concrete rams

OVERVIEW: This session is included here, as an option, primarily for use in locations where welded hydrams can be used. The purpose is to provide the basic parameters for designing fabricated valves, seat widths, and backing plates for valves. At this time, the sizes to be used will be taken from the concrete design theory, which will be somewhat oversized for metal. In time, specific charts may be developed for welded steel.

PREPARATION NOTES: Trainers will have made a decision about the type of constructions to be included in this training workshop. If a welded ram is to be constructed, i.e., if it has been decided that the expertise is available, the welded ram parts should be completed by this time. It is not the purpose of this workshop to teach welding skills.

At least one hydram construction must be completed at this point so that measurements of seats can be taken.

MATERIALS: Handouts 10B - 10F Previously constructed rams Chalkboard/chalk; flipcharts/markers Welded ram design, Attachment 9A

 

PROCEDURES

NOTES

1.

Introduce session by recalling any problems participants may have had with pipefitting ram operation. Ask trainees to share any possible causes of these problems, and what might be done to avoid them.

Generally, valves are not seating quite right or are too small.

2.

Explain that the rams constructed to date can be used in a range of situations, and that the purpose of this activity is to look at the maximum h:H ratios for the rams, based on their construction, and the general sizing guidelines for rams.

 

3.

Have trainees, in groups, measure the following parts of the constructed rams: a) D, impulse valve opening, impulse valve plate thickness, rubber thickness, backing plate thickness, and seat width; b) check valve diameter, backing thickness, seat width.

 

4.

Distribute handouts 10B-F. Ask participants to determine optimal. range of h and H for the measurements they've taken. Ask it there are any irregularities in the proportions of the drive pipe diameter, impulse valve opening, etc., from design guidelines presented in Session 6, and how that might affect performance.

 

5.

Present design of welded steel rams, using same design parameters and sizing charts. Allow trainees to examine components prior to final welding, and check sizes.

 

6.

In small groups, design a welded ram for one participant's site. Allow 11½ hours for the design, present and critique.