7. UST Piping Corrosion Protection. NCDENR Division of Waste Management Underground Storage Tank Section

Transcription

1 7. UST Piping Corrosion Protection NCDENR Division of Waste Management Underground Storage Tank Section

2 1 Where piping connects to tank Piping Corrosion Protection 2 Main run of piping 3 Where piping connects to dispenser

3 Containment Sump over tank Verify piping material Verify isolation of metal components Always check it is clean and dry

4 UST Site Diagram: UST UST Fuel Fuel Mart Mart Raleigh Raleigh Blvd Blvd Spill Spill Bucket Bucket Overfill Overfill Prevention Prevention Flapper Valve Flapper Valve Vapor Vapor Recovery Recovery Coaxial Coaxial Containment STP STP sump * * * Hart Hart Road Road Fuel Fuel Mart Mart 27 27

5 Piping - Corrosion Protection: - where piping connects to tank 1 - main run of piping 2 - where piping connects to dispenser 3 Find the pink numbers in your checklist Isolated, Booted FLEX, FRP, DW FLEX/FRP Sacrificial Anodes or (SA) Impressed Current or (IC) N/A (generator tank) Unknown violation?

6 Isolated, Booted FLEX, DW FLEX FRP, DW FRP Sacrificial Anodes (SA) Impressed Current (IC) N/A (generator tank) Unknown violation?

7 1 Where piping connects to tank Piping Corrosion Protection 2 Main run of piping 3 Where piping connects to dispenser

8 Isolation 1 Where piping connects to tank 3 Where piping connects to dispenser

9 Piping at TANK END in a containment sump ISOLATED

10 ISOLATED: Piping at TANK END in a containment sump FRP Pipe Flexible connector

11 ISOLATED: Piping at TANK END not in contact with soil

12 BOOTED: Piping at DISPENSER END is booted If buried (not visible) must verify in writing

13 Isolation for Piping Corrosion Protection Isolated OR Booted Isolated OR Booted N/A N/A Visual, Invoice, Contractor report Visual, Invoice, Contractor report N/A N/A

14 Non-corrodible Material 2 Main run of piping

15 NON-CORRODIBLE MATERIALS FRP (Fiberglass Reinforced Plastic) DW FRP (Double- Walled FRP)

16 Non-corrodible Materials: Flexible piping FLEX DW Flex (double wall flex)

17 Non-corrodible Materials: Written verification of piping material Installation invoice Repair invoice Visual verification

18 Non-corrodible Materials FRP, Flex N/A Visual; Repair or Installation invoice N/A

19 1 Where piping connects to tank Sacrificial Anodes 2 Main run of piping 3 Where piping connects to dispenser

20 Anode corrodes instead of piping component SACRIFICIAL ANODES

21 Sacrificial Anodes: Anodes connected via wires to metal piping

22 Sacrificial Anodes: Test every 3 years Hire a qualified cathodic protection tester Report results on UST-7A form Form is at

23 Sacrificial Anodes Sacrificial Anodes Every 3 years Sacrificial Anodes Every 3 years UST- 7A (3 years from previous test) UST- 7A (3 years from previous test)

24 24 1 Where piping connects to tank Impressed Current 2 Main run of piping 3 Where piping connects to dispenser

25 IMPRESSED CURRENT Anodes located in soil around structures to be protected Electrical current is applied to anodes

26 Impressed Current: Requires dedicated and protected circuit Power must not be interrupted (except during testing) Breaks in wiring result in system failure

27 Impressed Current Requirements: Operator must inspect system every 60 days Make sure NOT reading zero Rectifier Make sure meter never loses power

28 Impressed Current Records Test IC system every 3 years Hire a qualified cathodic protection tester Report results on UST-7B form

29 Impressed Current Impressed Current 60-days, 3 years Rectifier readings UST-7B 60 days from previous 3 years from previous

30 Problems with Piping Corrosion Protection Inoperative corrosion protection systems: - [IC that are not operational] Failed corrosion protection systems: - [IC or galvanic (SA) systems that are not providing adequate corrosion protection)] Specific requirements for each situation: - Guidance Documents - Corrosion Protection

31 Enter Primary Operators reported by online vendors Next up: Leak Detection