Section 170.430  Interior Lining and Lining Inspection  of UST Systems

 

a)         Tank lining requirements.

 

1)         Interior lining procedures.  A tank may be lined as needed by following the steps outlined in this Section.  

 

A)        Tank Entry.  Before entering tanks, the procedures described in API Publication 2015 and 2015A, incorporated by reference in Section 170.410, shall be complied with.  This includes checking the oxygen content inside the tank with a properly calibrated oxygen monitor.  At all times, personnel entering the tank shall be equipped with positive pressure air supplied equipment with full face enclosure and safety harness connected to a safety line held by an attendant outside the tank.  Oil and water-resistant rubber or neoprene boots and gloves shall be worn.  Clothing shall cover the arms, legs, torso and head of tank entry personnel.  Disposable clothing, impervious to product, is preferred.  Clothing saturated with product shall be removed immediately upon departure from the tank.  All personnel working inside the tank shall be familiar with ANSI Z117.1, incorporated by reference in Section 170.410.  Tests with the combustible gas indicator and oxygen monitor shall be performed periodically in the tank to ascertain that the tank vapors and oxygen content are in the safe range.  It shall be recognized that if the tank is perforated, product or vapors that have leaked into the soil may re-enter the tank through a perforation.  The vent line shall remain clear and unobstructed to allow continuous ventilation.  All other lines and openings shall be plugged or capped off to insure no liquids or vapors may enter the tank during the lining operation.

 

B)        Application of Lining.  Prior to the application of lining material, a ¼ inch steel reinforcing plate rolled to the contour of the tank and with minimum dimensions of 8 inches by 8 inches shall be installed under the fill (drop) tube and gauging tube.  This plate shall be covered with fiberglass cloth embedded in resin.  The blast-cleaned surface shall be coated within eight hours after blasting and before any visible rusting occurs.  Only those lining materials meeting the specifications in API Publication 1631 and NLPA 631, incorporated by reference in Section 170.410, shall be used.  Manufacturer's instructions are to be complied with on handling and mixing of resin compounds, and these compounds shall be applied to the entire interior surface of the tank by the manufacturer or the manufacturer's designated distributor following the specified method of application, to the designated thickness and at the recommended application temperature.  If a heater is used to accelerate the curing process, all other work which might release flammable vapors shall be halted, and the heating unit shall be attended whenever it is in operation. The coating shall be cured thoroughly to the manufacturer's specifications and checked for air pockets and pinholes using a Holiday Detector.  If any exceptions are found, they shall be repaired to manufacturer's specifications. The contractor shall protect the coated surfaces from contamination by foreign matter.  The coating thickness shall be checked with an Elcometer Thickness Gauge or equivalent and tested for hardness using a Barcol Hardness Tester or equivalent to ensure compliance with manufacturer's specifications.

 

C)        Tank Closing.  If a tank has been previously lined and passes its internal inspection, the following may be done in lieu of the manway requirements:

 

i)          A ¼ inch thick steel cover plate, rolled to the contour of the tank, shall be made to overlap the hole at least two inches on each side (e.g., should measure at least 26 inches by 26 inches, if manhole was cut 22 inches by 22 inches);

 

ii)         The cover shall be used as a template to locate ¾ inch diameter holes not exceeding five inch centers, one inch from the edge of the cover;

 

iii)         The cover plate shall be sandblasted to White Metal on both sides, and the entire inside surface shall be coated with coating material to act as a gasket;

 

           

 

iv)        After being bolted to the tank, the coverplate and surrounding tank surface shall be properly sandblasted, coated with coating material and allowed to cure before backfilling the hole;

 

v)         A precision test shall be performed any time an underground storage tank is entered to install a manway, install a coverplate after lining, or do an internal inspection of the tank.  This shall be done within 3 days after backfilling and is the responsibility of the contractor.

 

D)        Tank closing after entry procedures.  If a tank is being lined for the first time or subsequently is being totally lined, the following shall apply:

 

i)          Attach a manway no less than 18 inches in diameter that fits the contour of the tank.  This manway shall be surrounded with self-supporting material and be accessible from surface grade.

 

ii)         The manway shall be used as a template around which will be located ¾-inch diameter holes, 5 inches apart from center to center, one inch from the edge, and overlapping the entry hole at least 2 inches on each side, or welded in place if soil conditions will allow (no contamination is present). The lining material shall extend into the neck of the manway.

 

E)         Initial tank lining or subsequent total lining shall conform to NLPA Standard 631, incorporated by reference in Section 170.410.  The inspection of the manway installation and internal lining shall be made by OSFM, STSS prior to installation of the manway lid.

 

F)         After the STSS inspection, a tank precision test shall be performed.  It shall be the responsibility of the contractor to have a precision test performed within 3 days after the lining procedure completion and submit the results within 10 days after completion of the test to the OSFM; test results that fail must be reported in writing on the prescribed form to the OSFM within 3 working days.

 

G)        Within 10 years after lining, and every five years thereafter, the lined tank shall be internally inspected and found to be structurally sound with the lining still performing in accordance with original design specifications. An interior lining inspection permit must be obtained to do an internal inspection. 

 

2)         Internal lining combined with cathodic protection.  A tank may be upgraded by both internal lining and cathodic protection if:

 

A)        The lining is installed in accordance with the requirements of subsection (b)(1) and Section 170.480; and

 

B)        The cathodic protection system meets the requirements of Section 170.420(a)(2)(B) through (D).  (The following codes and standards, incorporated by reference in Section 170.410, may be used to comply with this Section: API Recommended Practice 1631; NLPA Standard 631; NACE RPO285;  or API Recommended Practice 1632.)

 

An interior inspection for an installation of internal lining combined with cathodic protection is required only once, provided an interior inspection was performed in compliance with subsection (3)(A) or (B) above.

 

b)         Within 10 years after initial lining or total subsequent lining of a tank, a physical internal inspection shall be performed as follows:

 

1)         The procedures for tank lining in subsection (a) shall be followed while entry is made into an existing UST has been interred for internal inspection purposes.

 

2)         Once a UST has been entered, a visual inspection of the lining shall be made.  The lining shall be visually inspected for obvious evidence of peeling, blistering, surface wrinkling or roughing of the lining material.  Repairs (touchup) to existing linings will be allowed up to 30% of the total surface area of the lining being inspected on a single tank.

 

A)         Testing shall be done to check the thickness of the shell and heads of the tank.  The average metal thickness shall be at least 75% of the original tank metal thickness.  Ultrasonic testing shall be done in accordance with Chapter B7 of NLPA Standard 631, incorporated by reference in Section 170.410.

 

i)           Tanks not meeting the wall thickness requirements shall be condemned and not put back into service as referenced in Section 8.1 of NLPA 631, 1991 edition.

 

ii)          No welding or cutting will be allowed inside the tank to repair holes or patch thin areas in any part of the tank.

 

B)         After a lined tank passes both the visual and the tank wall thickness test, it must be tested for holidays (air pockets) in the lining material.  This test shall be performed using a holiday detector with a silicon brush electrode or other acceptable instrument to ensure the integrity of the lining material.  The internal inspection holiday test shall be conducted at a rate of at least 100 volts per mil of nominal lining thickness, but in no case less than 12,500 volts or more than 35,000 volts.  Any holidays discovered during this internal inspection may be repaired as long as the repairs do not exceed 30% of the total surface area of a single tank.  Tanks with over 30% repaired areas shall be condemned, and not put back into service.  The repair contractor must certify to the OSFM that the coating materials used for repair are compatible to both the existing coating and the product being stored in the tank.

 

C)         If all previous testing ensures the integrity of the lining, it shall then be tested for hardness.  Lining hardness test shall be performed using a Barcol Hardness Tester or another acceptable instrument to determine that the lining was properly cured when installed or that it has not been affected by the product stored.  The overall hardness must meet the lining manufacturer’s specifications for the product stored.  In the event that some areas pass the hardness test and other areas fail the hardness test, the failed area may be removed and replaced as long as the failed area does not exceed 30% of the total surface area of a single tank.  Tanks with over 30% repaired areas shall be condemned, and not put back into service.  The repair contractor must certify to the OSFM that the coating materials used for repairs are compatible to both the existing coating and the product being stored in the tank.

 

D)         The final test to verify that an existing lining still meets the manufacturer’s original specifications shall determine the thickness of the coating.  The entire interior tank lining wall surface shall be no less than 100 mils thick with a nominal (i.e., approximate) thickness of 125 mils.  If any areas of the existing coating do not meet the 100 mils minimum thickness requirement, those areas may be overlaid to build up the coating thickness to meet or exceed the minimum requirement.  Newly overlaid areas may not exceed a total of 30% of the total surface area on a single tank.  Tanks with over 30% of their coating needing overlay to meet the 100 mils minimum thickness requirement shall be condemned and not put back into service.  The repair contractor must certify to the OSFM that the coating materials used for repairs are compatible with both the existing coating and the product being stored in the tank.

 

E)         Tanks that are condemned due to the 30% requirement in subsection (b)(2)(B), (C), and (D) of this Section can be lined if the tank meets recertification requirements and, if not, must be decommissioned within 6 months after condemnation.

 

F)         Where applicable, interior inspections of lined fiberglass tanks shall be the same as lined steel tanks, except testing will not be required for tank thickness and for holidays in the lining material.

 

G)        The manufacturer shall certify compatibility of the lining material with product to be stored by submitting to OSFM the following data.

 

i)          Laboratory Data:

 

•           Bonded Linings: When applied to properly prepared steel, concrete, fiberglass, and other tank surfaces, bonded linings shall maintain a minimum useful life of 10 years.

 

•        Coefficient of Thermal Expansion: The coefficient of thermal expansion of the lining shall not result in loss of bonding due to normal operating temperature changes.

 

•        Immersion Tests: Representative lining samples shall be tested to determine compatibility of the lining material with stored products. Samples shall be immersed in the liquids listed below at either 38º C (100º F) for periods of one, 3, 6 and 12 months. Upon completion of each immersion period, testing of the samples must verify that the lining and repair materials have not substantially deteriorated.

 

ii)         Test Data: The following tests, standards and equipment shall be conducted as indicated in the following:

 

•        Bonding Strength, ASTM D4541 using Elecometer 106 with rating of 0-2000 lbs. per sq. inch

 

•        Flexural Strength, ASTM D790

 

•        Impact Resistance, ASTM D2794

 

•        Barcol Hardness, ASTM D2583 using Barber Coleman GYZJ 935-1

 

•        Film integrity ASTM D543 Procedure 1

 

iii)         Liquids for Immersion Testing shall follow ASTM Reference Fuel C, Unleaded Gasoline, Leaded Gasoline, No. 2 Fuel Oil or Diesel Fuel, Toluene, Xylene, Gasohol (10% Ethanol), Oxinol-50 (90.0% gasoline, 5.00% methanol and 5.00% GTBA) 85% methanol, 15% gasoline, and distilled water.  Physical properties, after the final immersion period, shall be a minimum of 30% of the original physical properties before immersion with a stable trend indicating little or no further long-term deterioration for Toluene, Xylene, and distilled water; and 50% for all other listed material.

 

3)         During the Operational Safety Inspection, the contractor will not be allowed to either cut a new access hole into the tank, nor break open an existing entrance patch until all the required testing equipment is on site.  Also, a complete set of OSFM reporting forms must also be onsite before the entering process may begin.

 

4)         In cases where the tank itself passes the 75% minimum steel thickness test, yet the lining is condemned, the total original lining may be removed and a new lining installed.  This will require another lining permit.  However, the tank thickness must be re-tested after lining has been removed to verify that it will still meet minimum thickness requirements of Chapter B of NLPA 631, incorporated by reference in Section 170.410.

 

5)         The entrance manhole, hole or patch opening shall be closed and sealed. When a bolted manway is to be installed as a new access opening for future access use, an upgrade permit will be required to make this type of improvement to the tank.  No upgrade permit will be required if a manway is installed in conjunction with a lining permit or lining inspection permit, with manholes bolted to the tank top only when in conjunction with an inspection as not to damage the existing lining.

 

6)         After all work is completed on the inspection process, the tank must be precision tested.  This precision test is the responsibility of the contractor. Test results must be submitted to OSFM within 10 days after the test. In the event of a test failure, results must be submitted within 3 days.

 

7)         Written documentation of all inspection data must be submitted to the OSFM within 10 days after a passed inspection and within 10 days after repairs to the coating on a form approved by the OSFM.

 

8)         Every 5 years after the 10-year internal inspection, the tank must be re-inspected.  This can be done by a physical inspection or by another method approved by OSFM.

 

9)         All interior inspections require an Internal Inspection Permit.

 

c)          UST lining, subsequent lining, and internal inspections shall meet the following OSFM requirements:

 

1)         Secure proper permitting and obtain OSI schedule.

 

2)         Contractor shall present to OSFM inspector the OSHA Confined Space Entry permit for this job.

 

3)         All monitoring equipment shall be maintained according to manufacturer’s specifications.

 

4)         Establish an exclusion zone within which smoking is prohibited.  The use of spark producing/non-explosion proof equipment is prohibited in the vapor hazard area.

 

5)         USTs to be entered shall be isolated from all distribution lines, siphons, manifolds and manifold vent systems.

 

6)         Remove all liquids from the tank using explosion proof pumps or hand pumps.

 

7)         The tank atmosphere and the excavation area shall be regularly monitored, with a combustible gas indicator, for flammable or combustible vapor concentration.  Monitoring of the UST shall be done at 3 levels in the tank: top, middle and bottom.  Lower explosive limits (LEL) of 5% or less, or oxygen of 5% or less, shall be attained.

 

8)         Vapor freeing shall be done in accordance with API 1631 Section 2.4.  When vapor freeing the tank with compressed air or using inert gases under pressure, all devices shall be bonded to the tank, and the tank shall be grounded to a separated ground.  When using inert gases, the cylinder shall be equipped with a pressure gauge, so that no more than 5 psi can be discharged into the tank during vapor freeing procedures.  To ensure and maintain proper grounding and bonding, such connections shall be tested by the contractor for continuity.  This testing shall be done with equipment designed for continuity testing.

 

9)         OSFM personnel shall be on site before cutting and cleaning or entry operations may proceed.

 

10)          If no access exists, an opening with the minimum dimensions of 18 inches by 18 inches shall be cut in the top of the UST using non-sparking equipment in preparation for a manway. Manways must be installed and be accessible from surface grade by way of a non-collapsible structure.

 

11)          Personal protective equipment shall be in accordance with API 1631.

 

12)          Cutting, cleaning and application of lining material shall be done in accordance with manufacturer’s specifications and OSFM requirements.

 

13)          It shall be the responsibility of the lining contractor to have a precision test performed within 3 days after backfilling and to submit the results to the OSFM within 10 days on forms prescribed by OSFM.

 

14)          Tank owner shall file an amended Notification form prescribed by the OSFM within 30 days after the tank has been lined.

 

15)          For performing internal inspections, once a tank has been reclassified as a non-hazardous confined space, a positive flow of fresh air must be supplied into the tank in lieu of supplied air and continuous monitoring must be performed during the operation.

 

(Source:  Amended at 27 Ill. Reg. 8164, effective May 1, 2003)