Sample Job Sheet

Installing Suction and Discharge Lines for Packages Air Conditioning Unit and Commercial Refrigeration Equipment

Objectives: At the end of this practice, the learner/trainee should be able to: o Determine the number and type of fittings used in piping

installation o Determine the total length and size of pipe to use o Layout pipe for installation o Perform pipe joint using acetylene o Practice safety and proper housekeeping

Materials, Tools and Equipment:

Materials o Copper tube 0D x 30ft, 3/8 0D x 20ft - 4 pcs o Installation plan - 1 pc o Silver rod - 15 pcs o Silver flux - 1 quart o Elbow 0 - 6 pcs o Sand paper - 3 pcs

Tools o Push-pull rule - 1 pc o Steel meter - 1 pc

Equipment o Acetylene - 1 set o Electric drill - 1 set o Hole saw - 1 unit

Instrument o Leak Detector - 1 unit

Personal Protective Equipment o Safety glass - o Gloves - o Safety shoes -

Introduction:

The correct size, layout, type and installation of tubing, piping and fittings helps to keep the refrigerating and air conditioning systems operate properly and prevent refrigerant loss. The piping system carries refrigerant to the evaporator, compressor, condenser and expansion valve. It also provides pathways for oil return to the compressor. It is also used to transport water to (and from) chiller thermal units and between cooling towers and condensers. Careless handling of tubing, poor soldering or brazing techniques may cause serious damage to the system components.

Procedure:

Before performing this activity, make sure that you are using the required personal protective equipment for this task. 1. Prepare the necessary tools and the

acetylene equipment

2. Based on the working drawing, determine the number of elbow couplings and the diameter of pipes to be used.

See working plan at the back for larger view

3. Based on the working drawing and the actual location, determine the length, diameter and number of pipes to be used.

4. Based on working drawing

5. Measure the pipe to be cut from coupling to elbow, as shown.

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6. Cut the pipe according to the desired length, as shown.

7. Insulate the pipe, as shown.

8. Join the pipes either by brazing or by using flared fittings.

Note: Put 2 to 3 P.S.I. nitrogen while brazing to prevent oxidizing of pipe

9. Clamp the tubes and pipe securely. Install brackets and support, if necessary.

10. Based on the working drawing, install the discharge line.

11. Based on the working drawing, install filter drier and sight glass.

12. Based on the working drawing, install the suction line.

13. Execute flushing for refrigeration piping

Note: Isolate filter drier, sight glass, AHU

and ACCU

14. Leak tests the unit.

15. Vacuum the unit. If there is no leak, the system is now ready for charging.

16. Check your work using the criteria

below. Inform your instructor if you passed the self-assessment.

17. Perform housekeeping

Evaluation: Project

Check your work using the criteria below (Gaining all YES answers indicate that you have done the job according to the required standard. Gaining NO answer will require you to correct your work).

Criteria Yes No The size of pipes and fittings used are the same with the working

drawing

The number of fittings used is the same with the working drawing or installation plan

Lengths of pipe are the same as specified in working drawing Pipes are laid out following the working drawing Piping system is securely mounted with the use of clamp, brackets

and supports

Pipes that require insulation are insulated The piping system is leak-free

Performance

While performing the activity, it is important that you assess your performance following the criteria below. An overall performance of YES means that you are ready to proceed to the next learning level. An overall performance of NO means that you need to repeat the activity to improve your performance

Criteria Yes No Pipes are cut following the prescribed procedure Pipes are bent following prescribed procedure Pipes are joined following prescribed procedure Clamps and brackets are installed following prescribed procedure Safety practices are demonstrated at all times Proper housekeeping are practiced at all times

Is the overall evaluation of performance acceptable?