3k onion tank contractor questions Rcvd 26 NOV 2019.docx

2 December 2019 3k Water Tank Solicitation Questions / Received Tuesday, November 26, 2019 3:25 PM

Question # 1: Please clarify that after 24 hr test within 30 min the tank needs to be unfolded and then filled to 3,750 gallons. How long until this test is considered complete? 24hours? Then, the same test tank will be drained and the tank put back in to the valise, unfolded, and then 3750 gallons of water filled. Again is the test 24 hours for results?

Answer: The test is complete at the end of a 125% capacity fill and all inspections conclude to verify the tank does not display any flaking, cracking, or separation of the tank body material or leakage. Repeat same for high temperature test. Clarification on the unfolding procedure. This can be conducted outside the environmental chamber within 30 minutes of removal and the 125% overfill conducted per contractor time line after full inspection of unfolded tank.

4.5.5 Long term storage. The fully packaged tank assembly within its valise shall be subjected to a low temperature environment of at or below -28° F for a period of 24 hours. The ambient temperature shall then be increased to no more than -25° F, for an additional 24 hours. At the end of this period, while still at or below –25° F, the tank shall be unfolded in not more than 30 minutes. The tank assembly shall be removed from the low temperature environment. The tank shall be filled to 125% of capacity with drinking water. Any flaking, cracking, or separation of the tank body material or leakage shall constitute failure of this test. The fully packaged tank assembly within its valise shall be subjected to a high temperature environment of at least 180° F for a period of 24 hours. The ambient temperature shall then be decreased to no less than 140° F for an additional 24 hours. At the end of this period, with the ambient temperature at or above 125° F, the tank shall be unfolded in not more than 30 minutes. The tank assembly shall be removed from the high temperature environment. The tank shall be filled to 125% of capacity with drinking water. Any flaking, cracking, or separation of the tank body material or leakage shall constitute failure of this test.

Question # 2: Is the ground cloth and the tank itself required to be made from the same material?

Answer: Ground cloth material is not required to be same as tank material, however it is part of the assembly and is required to meet following requirements from ATPD 2344:

3.3.1.1 Puncture resistance. The tank and ground cloth material shall have a puncture resistance of at least 150 lbs when tested in accordance with ASTM-D751.

3.3.1.2 Ozone resistance. The tank, valise and ground cloth shall be constructed from ozone resistant materials. 3.3.3 Material deterioration prevention and control. The tank assembly shall be fabricated from compatible materials, inherently corrosion resistant or treated to provide protection against various forms of corrosion or deterioration under conditions stated herein.

3.3.4 Recycled, recovered, or environmentally preferable materials. Recycled, recovered (see 6.5.1), or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds operational and maintenance requirements, and promotes economically advantageous life cycle costs. Used, rebuilt, or re-manufactured components, pieces, and parts shall not be used.

3.3.5 Material imperfections. The tank assembly materials shall be free of any imperfections that may affect tank assembly performance, and if applicable, shall be free from blisters (see 6.5.2), holidays (see 6.5.3), or pinholes (see 6.5.4) and shall show no sign of coating delamination.

3.3.6 Chemical resistance. The tank assembly shall be resistant to chlorine and sodium bisulfite at concentrations resulting from controlled usage levels normally used in drinking water applications. Tank assembly shall also be resistant to chemicals such as bleach in concentrations used for cleaning and for sterilization purposes.

Question # 3: Does the Berry Amendment apply to all fabric used in this requirement?

Answer: Yes, the Berry Amendment applies to all fabric used in this requirement.

Question # 4: Please clarify the testing steps the government is requiring.

Question #5: May we get clarification that the tank will be rotated 4 times for a total test time at the 1500 gallons and then the tank will be filled to 3000 gallons. Then, that the test will be repeated on four sides for 15 minutes each.

Answer: That is correct. Paragraph 4.4.7 Sand testing is to be performed on 4 sides of the tank (90 degree locations) at 1500 gallons and repeated on 4 sides of tank at 3000 gallons. Provided paragraph 4.4.7 Sand below, as question was assumed to be specific to this verification test.

4.4.7 Sand. To verify conformance to 3.4.7, the tank assembly shall be tested IAW MIL-STD-810 Procedure II of Method 510. The tank assembly filled to 1500 ± 20 gallons shall be subjected to blowing sand condition for a minimum total of 60 minutes, 15 minutes per side. The first side shall be with the wind blowing towards the male discharge port, then rotate in 90 degree increments to the remaining three sides. The blowing sand concentration shall be maintained at 0.0623 ± 0.015 g/ft3. The air velocity shall be 3540 ft/min for blowing sand. This test shall be repeated with the tank filled to 3000 ± 20 gallons. Upon test completion, the tank assembly shall be inspected for visible signs of damage and the interior of the tank shall be inspected for sand particles. Visual damage to the tank or sand inside the tank shall result in failure of this test.

Question #6: At overfill is the 12 inch minimum distance beyond the tank required or when the tank is at overfill can the 12 inch minimum perimeter be less?

Answer: per 3.4.8 Ground cloth. A ground cloth shall be provided with each tank. The ground cloth shall extend a minimum of 12 inches beyond the tank perimeter at all levels of fill for the entire service life of the tank.

All levels of fill include empty thru overfill conditions and so the ground cloth should extend at least 12 inches beyond tank bottom perimeter at all water volume conditions up to 3,750.

Question # 7: Depending on the design can the layout of the ground cloth be different from 1 X 13 as long as the 169 square foot envelope is maintained?

Answer: Per 3.4.9 Footprint. The tank assembly shall be deployable within an area of 169 square feet or 13 x 13 feet depending on tank design shape.

The 13 x 13 feet deployable area would be for the tank only. The tank should not require more than a 13 x 13 foot area or 169 square feet when in any water level condition, including overfill condition. The ground cloth can extend beyond the 13 x 13 foot area as long as it complies with paragraph 3.4.8 requirement.

Question #8: Must all of the components on the inside of the crate be wrapped in Bagged material: Mil-PRF-131 Class 1, Type III, including the accessory box which is also required to be a water resistant box?

Answer: Everything is required to be in Bagged material: Mil-PRF-131 Class 1, Type III, including the accessory box which is also required to be a water resistant box.

Question #9: ASTM D6251, Type III, Class 2, Style A crates are extremely detailed in design and very expensive. Does the crate/container need to be this robust or can it be more of a commercial equivalent container with an added water protection coating?

Answer: ASTM D6251 crate is required, a commercial equivalent is not acceptable.