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close this bookAppropriate Community Technology - A Training Manual (Peace Corps, 1982, 685 p.)
close this folderPhase IV: Solar water heaters
View the document(introduction...)
View the documentPhase IV Calendar
View the documentSession 1. The role of the volunteer in development: international development part 2: the green revolution: successes and failures
View the documentSession 2. Introduction to solar water heaters
View the documentSession 3. Assessing community water needs and uses
View the documentSession 4. Introduction to solar water heating: determining hot water demand
View the documentSession 5. Plumbing a solar water heater
View the documentSession 6. Sizing a solar water heater
View the documentSession 7. Demonstrating a technical concept
View the documentSession 8. Shade mapping and solar siting
View the documentSession 9. Design of solar water heaters.
View the documentSession 10. Construction of solar water heaters
View the documentSession 11. Multi-media standard first aid
View the documentSession 12. Wind technology
View the documentSession 13. Volunteer in development part 2: women in development
View the documentSession 14. House design in four climates
View the documentSession 15. Presentation of solar water heaters

Session 5. Plumbing a solar water heater

Total time:

2 hours

Objectives:

To identify plumbing fittings and their uses


* To identify plumbing tools such as pipe wrenches, pipe vise, cutter and threaders


* To demonstrate the mechanisms for galvanized pipe cutting and threading


* To cement PVC (poly vinyl chloride) pipe and fittings together such that no leaks occur


* To diagram a plumbing schematic of a solar water heater

Resources:

* Attachment IV-5-A, "Plumbing Fitting Nomenclature"


* Attachment IV-5-B, "Plumbing Schematics Worksheet"


* Attachment IV-5-C, "Plumbing Solar Water Heaters''


* Bainbridge, The Integral Passive Solar Water Heater Book


* Anderson, The Solar Home Book, pp. 209-226


* VITA, Village Technology Handbook, pp. 86-91


* Burton, "Integral Passive Solar Water Heater Plans"

Materials:

A variety of plumbing fittings (nipples, elbows, tees, 45's, couplings, unions, lock nuts, adapters, etc.) in 12 and 18 mm (1/2" and 3/4") galvanized iron, and PVC pipes, gate and globe valves, hose clamps, pipe vise, pipe wrenches, pipe cutter, pipe reamer, pipe threader, threading oil, threading compound, PVC solvent, PVC primer

Procedures:

Step 1. (5 minutes)
Present the session objectives and outline the activities.

Step 2. (20 minutes)
Distribute Attachment IV-5-A, "Plumbing Fitting Nomenclature," Spread the assortment of galvanized and PVC plumbing fittings on a large table and have the participants identify and discuss the use of each fitting.

Trainer Notes

Allow a few minutes for small groups to assemble five to ten fittings with the understanding that each small group will then name each fitting in the assembly, from end to end, with help from the group as needed. Or, hold up each fitting, piece by piece, and ask the group to name it.

Explain that it is important during training to know plumbing terminology or nomenclature in order to:

* Complete the plumbing schematic worksheet (See Step 6)

* Complete the solar water heater plumbing schematic and parts list to be developed during the design session

* Be more clear during construction when one member of the small construction group is sent to get a "1/2" "whatchamacallit" from the shop

* Better understand any new names for fittings which may exist in the participant's country of assignment

Be certain that this step includes a discussion of how and when a pipe union should be used.

Step 3. (15 minutes)
Demonstrate and describe the cutting, reaming and threading of galvanized pipe using the appropriate tools.

Trainer Notes

You may choose to ask for volunteers with plumbing experience to demonstrate to the rest of the group how galvanized pipe is cut, reamed and threaded. Be certain that the volunteer is complete in his/her description. Include proper tool use instructions as needed, especially with the cutter, the pipe vise, pipe wrenches, reamer and pipe oil.

Step 4. (10 minutes)
Demonstrate and describe the joining of galvanized pipe using pipe wrenches and pipe joint compound.

Trainer Notes

Again, ask for volunteers from the group to demonstrate.

Mention the different pipe joint compounds used throughout the world, including oil, oiled rope or twine (China), lead rope, teflon rope, etc.

Describe the use of pipe wrenches (i.e., two are needed at one time, how they automatically ratchet, the proper way to hold, adjust, and use a pipe wrench, etc.).

Explain that pipe joint compound is placed only on the male threads of the pipe joint so that the compound is evenly spread over the threads as the fitting is tightened.

Step 5. (15 minutes)
Demonstrate and describe the joining of PVC pipe and fittings, using primer and/or solvent.

Trainer Notes

Ask for volunteers from the group to demonstrate this step.

Point out that:

* Solvent is placed on the male part only for small size pipe (12 and 18 mm) but for large pipe it is O.K. to use solvent on both ends. If solvent is used on the female end, it may form a bubble and seal off the smaller sized pipes as the two pieces are pressed together. With large pipe, this is less likely to happen.

* The two pieces need to be twisted together and held still for a few seconds to keep them together.

* PVC fittings are not re-usable.

Describe the process that the solvent goes through to "melt" a thin layer of pipe and fitting together to form the seal.

Discuss the usefulness of PVC pipe in solar water heaters, since it cannot take very high temperatures and it doesn't transfer heat well.

Step 6. (20 minutes)
Distribute Attachments IV-5-B and IV-5C and have the participants complete the plumbing schematic of the solar water heater shown in Attachment IV-5-8.

Trainer Notes

Allow the participants to work individually or in groups of two to complete the schematic. Explain that the answers are partially described in Attachment IV-5-C. Remind them to label all parts, including pipe size, type, fittings, valves, etc. Remind them of the use of unions in plumbing.

Step 7. (20 minutes)
Have each individual or small group describe and explain their plumbing schematic to the group.

Trainer Notes

Be sure the criteria on the worksheet are addressed by each presentation.

After the first or second description, ask for any new or different schematics.

A. the end of the presentations, briefly identify and discus inexpensive and effective plumbing shortcuts:

* Explain how a tee-with-a-plug can replace a more expensive drain valve at the bottom of each tank.

* Ask how a mixing valve could be manufactured from scratch, using only one union (one tee, two valves and some nipples).

Step 8. (15 minutes)
Conclude the session with a brief discussion of plumbed vs. unplumbed solar water heaters, their advantages and disadvantages, and their applications in countries in which participants will be serving.

Trainer Notes

Allow time at the end of the session for cleanup and dismantling of any plumbing that was constructed during the session.

PLUMBING FITTING NOMENCLATURE


PLUMBING FITTING NOMENCLATURE

PLUMBING SCHEMATIC WORKSHEET

Directions:

This clinic originally had only cold water at the sink inside. You have just finished building a direct-gain solar water heater 'or the clinic and you need to plumb: (1) cold water to the solar heater and the sink, and (2) hot water to the sink. Use as few parts as necessary to reduce costs. Design a mixing valve to be used at the sink. Use valves and unions where needed. Label all pipe and fitting names and sizes.


PLUMBING SCHEMATIC WORKSHEET (Fig. 1)


PLUMBING SCHEMATIC WORKSHEET (Fig. 2)


PLUMBING SCHEMATIC WORKSHEET (Fig. 3)

PLUMBING SOLAR WATER HEATERS


A two-tank, pressurized solar water heater system and A three-tank, pressurized, solar water heater system.


A one-tank, non-pressurized solar water with mixing valves and A one-tank, non-pressurized "overflow" solar water heater system.