Section 170.421  Piping

a)         Underground piping installed or replaced shall be of double-wall construction and equipped with interstitial monitoring that meets the applicable requirements of Section 170.530(g) and 40 CFR 280.43(g) for all permits issued February 1, 2008 and after.  Any replaced piping that exceeds 20 feet or 50% of the total piping run shall require the entire pipe run to be replaced with double-wall, monitored piping.  Where the site has multiple distinct pipe runs, only that piping run being replaced shall be required to be double-wall construction.  Pressurized piping systems (including existing systems) shall also be equipped with automatic line leak detectors pursuant to Section 170.540(a).

b)         Piping, valves and fittings for flammable liquids shall be designed for the working pressures and structural stresses to which they may be subjected and approved for their intended use.  The application of any material shall not interfere with the normal operation of the shear valves, fusible links or any equipment installed under the dispensers or submersibles.  They shall be of steel or other materials suitable for use with the liquid being handled.  Pipe-wall thicknesses being determined in accordance with ANSI B31, incorporated by reference in Section 170.410, shall be deemed to comply with this Section, except that carbon steel pipe shall not be thinner than standard wall thickness listed in ANSI B36, incorporated by reference in Section 170.410.

c)         Non-metallic piping systems conforming to the requirements of ANSI B31, incorporated by reference in Section 170.410, for use with flammable and combustible liquids are permitted underground.

d)         After installation, pressurized piping shall be tested for 30 minutes at 1.5 times the working pressure or 50 PSI, whichever is higher.  Suction and vent piping shall be tested at a minimum positive pressure of 7 psi or in accordance with the manufacturer's recommended procedures.

e)         Piping that routinely contains regulated substances and is in contact with the ground, backfill or water shall be properly designed, constructed and protected from corrosion in accordance with a code of practice developed by a nationally recognized association or independent testing laboratory, as specified in this subsection, and all steel risers, vents, and fills in contact with the ground, backfill or water shall be dielectrically wrapped or coated:

1)         The piping is constructed of fiberglass-reinforced plastic (the following codes and standards, incorporated by reference in Section 170.410, may be used to comply with this subsection (e)(1):  UL 567; UL Canada Subject C107C; or UL Canada Standard CAN4-S633);

2)         The piping is constructed of steel and cathodically protected in the following manner:

A)        The piping is coated with a suitable dielectric material;

B)        Field-installed cathodic protection systems are designed by a corrosion expert;

C)        New impressed current systems are designed to allow determination of system operating status by means of permanently installed lights, amp, volts and hour gauges as required in Section 170.460 and existing impressed current systems must meet these requirements on or before November 1, 2003;

D)        Cathodic protection systems are operated and maintained in accordance with Section 170.460 (the following codes and standards, incorporated by reference in Section 170.410, may be used to comply with this subsection (e)(2):  NFPA 30; API Recommended Practice 1615; API Recommended Practice 1632; or NACE RPO285); or

E)         The piping construction and corrosion protection are determined by the Office of the State Fire Marshal to be designed to prevent the release or threatened release of any stored regulated substance, in a manner that is no less protective of human health and the environment than the requirements in subsections (c)(1) and (2).  Before the installation of any such piping, its construction and corrosion protection shall be submitted to the Office in writing, and the Office shall issue written approval.

f)          UST wiring procedures.  All wiring at UST locations shall be in accordance with NFPA 70, incorporated by reference in Section 170.410.  Wiring within 20 feet of tanks, within 20 feet of dispenser pumps or run in the product line trenches shall be installed in rigid metallic conduit or threaded steel conduit (or any petroleum or product resistant conduit approved for that use).  Electrical conduit shall maintain at least six inches of separation from product piping to avoid damage from abrasion or stray electrical current and shall be routed away from product piping.  Minimum cover is required in accordance with Table 300-5 of NFPA 70, incorporated by reference in Section 170.410.  Intrinsically safe wiring shall be in conduit when installed within Class I locations, as specified in NFPA 70, incorporated by reference in Section 170.410.  Caution should be taken when grounding since it impairs cathodic protection of metallic tanks or piping.  When locating electrical wiring in the same trench as the product lines, the conduit shall be positioned on either side of the product piping but not above or below the product piping.  This electrical conduit shall cross over the top of any product piping whenever a cross-over is necessary.  A six-inch separation shall be maintained at all times, even during a cross-over.  All cross-overs shall be kept to a minimum.  All electrical power shall be shut off at the immediate location where installations, repairs or upgrades are in progress.  All electrical seal-offs are to be properly filled whether being used or for future use.

g)           All related wiring shall be inspected during UST final inspection.

h)           A positive shut off valve shall be installed on the product line at the submersible or at the tank for all suction systems on all new installations and when piping is replaced at existing sites and made accessible at grade.  Extractor valve will be accepted on European suction instead of positive shut off valve.

i)            Vent lines will be tested from the tank to grade level at the time of installation.  This test will be done at 7 psi minimum or at the pressure recommended by the manufacturer.  This test will be performed at the time of the line PAI test.

j)            The application of any material shall not interfere with the normal operation of the shear valves or fusible links, or any equipment installed under dispensers or submersibles.

k)           Any time product piping is broken for repairs, a precision line tightness test must be conducted before the piping is put back into service.

(Source:  Amended at 33 Ill. Reg. 6069, effective April 24, 2009)