Specificaiton for Large Diameter Flex Duct Bellows

14999-27-901

SPEC. No 14999-27-901

30 October 2026

DISTRIBUTION STATEMENT A

Approved for Public Release: Distribution Unlimited
IRA-26-2111

SPECIFICATION FOR

LARGE DIAMETER FLEX DUCT BELLOWS ASSEMBLY

ARNOLD ENGINEERING DEVELOPMENT COMPLEX

ARNOLD AIR FORCE BASE, TENNESSEE 37389

14999-27-901
1.0

SCOPE

Provide two (2) 45.315-inch internal diameter flex duct bellow assemblies in accordance with Drawing RJ632279.18. The Contractor shall deliver the assemblies to Arnold AFB, Tennessee, 37389.

2.0

APPLICABLE DOCUMENTS

2.1

Government Documents: Not applicable.

2.2

Non-Government Documents:

2.2.1 American Society of Mechanical Engineers (ASME):

A. ASME B31.3, Ch. VII

Nonmetallic Piping and Piping Lined With Nonmetals

2.2.2 American Welding Society (AWS):

A. AWS D1.1

Structural Welding Code-Steel
2.2.3 Expansion Joint Manufacturer’s Association (latest publication):

A. EJMA Standards

Expansion Joint Manufacturers Association, Inc.
3.0

REQUIREMENTS

3.1

The flex duct bellows assemblies shall be fabricated in accordance with EJMA Standards and ASME Boiler and Pressure Vessel Code per Drawing RJ632279.18 (see Appendix A). Note: Boiler and Pressure Vessel Code-stamp is not required.

3.2

Welds shall conform to AWS D1.1.

3.3

Bellows material shall be silicone-coated 1523 fiberglass, 6-ply body, 0.12 inches thick (nominal). The Contractor shall submit all proposed material substitutions or other deviations from this specification to the Government for approval.

3.4

Bellows assemblies shall conform to the following design parameters: A. Working Pressure: 30 psid Internal, 15 psid External

B. Temperate Range: -60°F to +450°F

C. Test Pressure: 45 psig at 70 °F

D. Length Flexibility: ±0.375 inch

E. Radial Flexibility: ±0.25 inch

3.5

Cleanliness: The Contractor shall ensure the cavity between the bellows and the rings is clean and free of all foreign materials including but not limited to weld slag and splatter and metal shavings.

DISTRIBUTION STATEMENT A

Approved for Public Release: Distribution Unlimited
IRA-26-2111

14999-27-901
3.6

Documentation:

3.6.1 Provide the following documentation with delivery of the assemblies: 3.6.1.1

Visual inspection report.

3.6.1.2

Weld inspection report.

3.6.1.3

Pressure test inspection report.

3.6.1.4

Axial spring rate calculation and test results.

3.6.1.5

Standard Manufacturer Warranty.

4.0

VERIFICATION AND TESTING

4.1.

Assemblies shall be hydrostatically tested to 45 psig at 70 °F per ASME Boiler and Pressure Vessel Code.

4.2.

Welds shall be inspection per AWS D1.1.

4.3.

Assemblies spring rate in the axial direction shall be calculated and