ACADs (08-006) Covered Keywords Air compressors, aftercooler, afterfilter, moisture separator airflow. Description Supporting Material

Service&InstrumentAir 2

3 INSTRUMENT AND SERVICE AIR Number: AT-1260-PP-Air SystemsRev: 1 Author: Rob ThomasDate: 6/6/11 Approved: Date: References: 1 AT-1260-LP-Air Systems 2 V-LO-TX Instrument and Service Air System VOGTLE ELECTRIC GENERATING PLANT

Rev. No.DateReason for Revisions Author’s Initials Sup’s Initials 4

Objectives: 5 1. Describe the difference between service air and instrument air; state the purpose of each. 2. List the main components of the service / instrument air systems and describe their functions. 3. Describe the flowpath of air through the service / instrument air system using a one- line diagram.

Service & Instrument Air Purpose: Provide a source of reliable compressed air to air operated plant equipment. Uses: Service air is generally of lesser quality than instrument air. Service air is piped to outlets for temporary equipment and instrument air is piped to permanently-installed, pneumatically- operated equipment. 6

Rotary Air Compressor: Turbine Building Level A 7 a. 2 per unit b. Normal operating pressure 117 psig c. Capacity SCFM d. 200 HP motor e. Seal fluid seals the intermesh of two screw-type blades f. Air coolant receiver - cools seal fluid, removes fluid, and returns it back to screws

Reciprocating Air Compressor 8 a. 1 per unit, 1 shared b. Normal operating pressure 125 psig c. Capacity 885 SCFM d. 200 hp motor e. Piston and cylinder type f. Uses no seal fluid therefore no air coolant receiver needed

Aftercooler 9 Compressed air gets hot so must be cooled 7 (1 for each compressor) Air/water Heat Exchanger Air on shell side Cooling water on tube side Cooling water from Turbine Plant Closed Cooling Water (TPCCW)

Moisture Separator 10 a. 7 (1 per compressor) b. Mechanical type -- air flow hits baffles inside and drops water out c. Removes condensed moisture from cooled air

1 st & 2 nd Stage Contaminant Filters 11 a. Used with rotary compressor b. Backup seal oil removal c. 1 st stage =.3 micron 2 nd stage =.01 micron

Air Receiver 12 7 (1 per compressor) 150 ft. 3 Rated pressure 150 psig Dampening effect

Prefilter 13 3 total Coalescing type (oil vapor/particulate) Removes oil and contaminants before dryer

Air Dryer 14 Each dryer = two tanks w/ alumina desiccant Service Dryer: 1 dryer 1200 SCFM capacity Instrument Dryer: 2 parallel dryers 740 SCFM capacity

Afterfilter 15 3 (1 after each dryer) Filter desiccant fines Remove.07 micron

Service&InstrumentAir FLOW PATH: 1. Compressors 2. Aftercooler 3. Moisture separator 4. Contaminant filter 5. Air receiver

Service & Instrument Air FLOW PATH: 6.Pre-filter 7.Dryer 8.After Filter 9.To respective headers

Objectives Review: Describe the difference between service air and instrument air; state the purpose of each. 2. List the main components of the service / instrument air systems and describe their functions. 3. Describe the flowpath of air through the service / instrument air system using a one- line diagram.