Technical Note - ULC S668-12 Explained

TECHNICAL NOTES

Covering the world.

Protecting the Earth.

Rev. 10.15

ULC S668-12 EXPLAINED

SOLMAX.COM

CANADA - MALAYSIA - CHILE - USA - CHINA - SOUTH AFRICA - FRANCE - INDIA

SCOPE OF THE STANDARD ULC S668-12 is the standard for liners used for secondary containment of aboveground flammable and combustible liquid tanks. This Standard was developed and approved by the Underwriters’ Laboratories of Canada (ULC) Committee on Stationary Non-metallic Storage Containers for Flammable and Combustible Liquids.

This Standard sets forth minimum requirements for the material properties and performance of liners used for secondary containment under and around the area of tanks that are installed aboveground for the storage of flammable and combustible liquids. These liners are intended for permanent installation to contain spills or leakage of product for a temporary period.

In the event of spills, the removal and cleanup should be done within a period not exceeding 14 days.

This standard is based on six steps which are discussed in the following technical note.

BREAKDOWN OF THE STANDARD REQUIREMENTS First and foremost, liners can meet three (3) separate categories of this standard:

1. Reinforced coated fabrics or polymer films laminated onto textile substrates; 2. Non-reinforced – polymer films or extruded polymeric panels; 3. Spray-on liners.

Secondly, liners are submitted to a series of mechanical and performance tests. Some are set as minimum requirements such as the Vapour Transmission Rate (VTR) and the Tensile Strength (TS), while others serve as a benchmark for the third step mentioned later in this technical note. As a reference, the maximum VTR for an unreinforced liner is 20g/ (h•m2), while the minimum TS for the same liner is 500N. Thirdly, liners undergo a 30 days full immersion in which chemical resistance is tested. Samples are submitted to a series of standard chemicals found on an oil & gas platform. Chemical resistance is evaluated by measuring the volume and the weight gained by the liner after the 30 days immersion as well as the retained tensile strength for the same immersion period. The mass of the liner should not change by more than 10%, the volume should not vary by more than 20% and the tensile strength should not differ by more than 50% from the original values. The liners are then categorized based on the chemicals for which the liners meet the mass, volume and tensile strength criteria.

The following table exhibits the different categories of this standard.

EXPOSURE LIQUID

SECONDARY CONTAINMENT LINER CLASS IA

IP

IIP

III1

TEST FUELS AND CHEMICALS FOR SUBSECTIONS 5.3 AND 5.4, VAPOUR TRANSMISSION AND COMPATIBILITY TESTS 1

ASTM IRM 903

2

ASTM Reference Fuel C

x

100% Methanol

x

3

ASTM Reference Fuel H

5

100% Ethanol

4 6

B5 ≥ 202

7

x

x

x

x

x

x

x3

B20 ≥ 1002

8

x3

Specific chemicals

x3

ADDITIONAL TEST FLUIDS FOR SECTION 5.4, COMPATIBILITY TEST 9

pH 104 Sodium Carbonate Bicarbonate

11

Sulphuric Acid Dilute — pH3

10

Saturated Sodium Chloride

x

x

x

x

x

x

x

x

x

x

x

x

1 A Class III rating is for specific chemical or blend of chemicals and is in addition to any other rating. A secondary containment liner with a Class III rating is clearly marked to which chemical it can contain. When a secondary containmenr liner holds both a Class I or Class II with a class III rating, the ratings shall be clearly shown on the marking.

2 Biodiesel blends shall be a specific mixture of B100 in accordance with ASTM-D6751, Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels and ASTM- Reference Fuel F — D2 S15 (ultra low sulfur diesel fuel) from ASTM D975, Standard Specification for Diesel Fuel Oils.

3

Secondary containment liners shall be rated Class III for the containment of Biodiesel blends higher than 5% (B5).

4 pH of 10 is obtained by mixing 10.6 g/L of sodium carbonate and 8.4 g/L of sodium bicarbonate. A pH meter is to be used and the ratio of sodium carbonate to sodium bicarbonate is to be adjusted to obtain a pH of 10. The pH value is to be checked several times during the test.

Source: CAN/ULC S668-12

The fourth step of this Standard is meant to identify if the liner should be used for buried or exposed applications. This step defines the flammability of the liner material. A test specimen of the liner is exposed to a flame for 12 seconds must stop burning within 5 seconds to be considered flame retardant. Materials that meet this criterion are categorized as being suitable for exposed applications while those that do not satisfy the requirement are suited for buried applications.

The fifth step of the Standard consists of the liner’s roll marking. All rolls meeting the ULC S668 standard must have a permanent marking, at regular intervals along the length of it, which identifies the following information:

1.

2.

3.

4.

5.

Name of the Manufacturer Manufacturer’s product designation Standard number including year of publication, title and class designation “S” for reinforced and “U” for non-reinforced “E” for exposed and “NE” for non-exposed applications.

As an example, for a class IA, non-reinforced, non-exposed Solmax liner, each roll should be permanently marked as follows: Solmax [Product Code]-CAN/ULC-S668-12-IA-U-NE

The sixth and final step requires the manufacturer to provide a letter stating that the material supplied for a specific project meets or exceeds the requirements of a specific category of this Standard. The manufacturer is only required to provide the test data supporting the claim should the project engineer require it.

SOLMAX PRODUCTS Solmax HDPE and LLDPE geomembranes have been submitted to the rigorous testing protocol required by the Standard in order to evaluate the categories of the Standard that the products meet. As such, the below table identifies the categories that each series meets.

Series HDPE LLDPE

Thicknesses (mils/mm)

Class

Reinforced

Exposed

40/1 and up

IA

No

No

40/1 and up

IIP

As such, all Solmax 40 mils (1mm) or greater HDPE liners meet the following category:

No

No

Solmax [Product Code]-CAN/ULC-S668-12-IA-U-NE

While all Solmax 40 mils (1mm) or greater LLDPE liners meet the following category:

Solmax [Product Code]-CAN/ULC-S668-12-IIP-U-NE

All manufactured products by Solmax ,meeting the ULC S668 standard in its entirety, should be considered custom and thus will only be produced on a project-specification-basis.

Solmax cares to provide products having undergone thorough Manufacturing Quality Control (MQC) and uses distinctive manufacturing practices. Solmax strives to comply with stringent technical requirements and high environmental standards to ensure the reliability of its products.