Maricopa Community Colleges  MEC212   20032-20086 
Official Course Description: MCCCD Approval: 11/26/02
MEC212 20032-20086 L+L 1 Credit(s) 2 Period(s)
Maintaining Valves
Identification of valves and component parts. Operating principles, disassembly, installation, packing and repacking valves.
Prerequisites: Registered Apprentice status or permission of the apprenticeship coordinator.
Cross-References: ABC212
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MCCCD Official Course Competencies:
 
MEC212   20032-20086 Maintaining Valves
1. List and define trade terms and describe warranty issues pertaining to maintenance of valves. (I)
2. Given a display of valves, identify specific valves, their application and operating characteristics. (II)
3. Remove and install threaded valves. (III)
4. Identify, remove and install flanged valves. (III)
5. Replace valve stem O-rings. (IV)
6. Replace bonnet gaskets. (V)
7. Explain the purpose of valve packing and repack a valve. (VI)
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MCCCD Official Course Outline:
 
MEC212   20032-20086 Maintaining Valves
    I. Maintaining valves
        A. Terms
          1. Body
          2. Bonnet
          3. Disc
          4. Packing
          5. Port
          6. Seat
          7. Stem
          8. Trim
          9. Venturi port
        B. Warranty issues
      II. Valves
          A. Types
          B. Application
          C. Characteristics
        III. Removing and installing valves
            A. Component parts
            B. Removing and installing threaded valves
              1. Special precautions
              2. Isolate the system
              3. Drain and bleed
              4. Measure and cut
              5. Clean and thread pipe
              6. Select replacement valve
              7. Install new valve
              8. Restore pipeline to service ABC212Effective Term:
            C. Removing and installing flanged valves
              1. Special precautions
              2. Isolate the system
              3. Drain and bleed
              4. Remove bolts in proper order
              5. Support pipe
              6. Use proper rigging procedures
              7. Clean flange surfaces
              8. Select replacement valve
              9. Install new valve
              10. Follow proper torquing procedures
              11. Restore pipeline to service
          IV. Replacing valve stem o-rings
              A. Types of valve stems
                1. Rising stem
                2. Non-rising stem
                3. Outside screw and yoke system
              B. Component parts
              C. Removal
              D. Maintenance
              E. Installation
            V. Replacing bonnet gaskets
                A. Types of flanged bonnets
                  1. Bolted
                  2. Flanged with gasket
                  3. Flanged with ring type joint
                B. Component parts
                C. Removal
                D. Maintenance
                E. Installation
              VI. Packing valves
                  A. Packing
                  B. Packing shapes and materials
                  C. Repacking valves
                    1. Removal of valve
                    2. Removal of packing
                    3. Maintenance of valve
                    4. Repacking
                    5. Installation
                    6. Replace in service
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