High-pressure Air Availability

Most Aeronautical Test and Simulation Division facilities can supply up to 3,000 psi heated air with various burst disk capacities.

Pressure-Relief Devices

Relief devices are required in the system (but not necessarily in the model) and must be capable of discharging the full flow of the pressure source under all conditions including those resulting from malfunctions.

Users are to inform the Test Manager on the requirements of the maximum and minimum pressures the model can withstand to determine system burst disk pressures. Users must provide pressure relief devices appropriate to the model as required. If rapid air discharge constitutes a noise hazard, mufflers are required on discharge lines.

Users should check with the Test Manager to verify the appropriate burst disks are available; otherwise customers must supply their own.

Pressure System Codes

Models, support equipment, and test equipment using hydraulic, pneumatic, propulsion, or other systems with operating pressures above 15 psig are to be designed, fabricated, inspected, tested, and installed to comply with the following codes and definitions:

• ASME Boiler and Pressure Vessel Code
• ASME B31.1 Power Piping Code
• ASA Codes as sponsored by ASME
• Department of Transportation Regulations

Pressure System Components

The components of a pressure system include

• vessel
• relief devices
• piping

 

Testing/Storage

Pressure components that have been proof-tested must be stored in a clean, dry, sealed condition with controlled accessibility.

All pressure system components (including piping) are to be indelibly marked in a conspicuous place with sufficient information to determine:

• Part number
• Proof test pressure
• Working pressure
• Date of proof test
• Volumes and temperature range

 

Certification

All pressure system components must have current certification (valid throughout the test). Certifications are required annually. A certification report must be submitted for all tested systems.

Pressure Vessel

All shells, test chambers, tanks, and model parts designed for internal pressures greater than 15 psig are considered pressure vessels.

Pressure vessels must be designed in compliance with the latest edition of the ASME Boiler and Pressure Code, Section VIII or Section III.

Pressure-vessel welding must be in compliance with the ASME Boiler and Pressure Code as follows:

• Section IX for welding qualifications
• Section V for welding inspection

Pressure Piping

All piping must be designed, fabricated, inspected, tested, and installed in compliance with the latest edition of the ANSI Standard Code for Pressure Piping.

For powered models, the internal supply tubing is considered pressure piping.

Pressure vessels fabricated from standard pipe, standard pipe fittings, and standard flanges are also considered pressure piping. They are defined as those covered by these ANSI dimensional standards:

• Pipe: B.36.10 and B.36.19
• Fittings: B.16.9
• Flanges: B.16.5

Welders, welding operations, and welding procedures are to be qualified in compliance with Section IX, ASME Boiler and Pressure Vessel Code, except as modified by the applicable section of the Piping Code.

Allowances must be made as required or recommended by the Piping Code for pipe threading, corrosion, and wall thinning due to pipe bending.

Threaded joints, flange joints, and seal welding of threaded joints must be in compliance with the requirements and recommendations of the Piping Code.

Tube fittings must be in compliance with the latest issue of applicable Military Standards.

All service lines must be properly identified for working pressures, flow direction (in or out), and fluid or gas carried.