This specification establishes the requirements for seamless and welded titanium and titanium alloy tubes that have undergone a cold-working (rolling) procedure to optimize surface area and increase the heat transfer coefficient. This product, supplied by EV Group China, is designed for use in surface condensers, evaporators, heat exchangers, and coiled systems. The manufacturing technology allows for the production of tubes with a nominal outside diameter of up to 25.4 mm (1.0 inch).
The standard wall thickness of the blank is from 1.24 mm (0.049 inches). Upon individual request, EV Group China can provide the production of tubes with non-standard wall parameters, which are specified during the technical requirements agreement stage.
Tube products conforming to this standard are installed into tubesheets and support baffles of heat exchangers according to TEMA association requirements. The end sections of the tubes are expanded and subsequently welded to ensure the tightness of the assemblies. The supply of products with U-bends, as well as finned (profiled) tubes, is permitted. The geometric parameters of the bends and limit deviations are subject to mandatory visual and instrumental inspection.
In technical documentation, values in the inch-pound system are prioritized. Metric values in parentheses are provided for reference and are not normative for acceptance testing.
The test methods described in sections 8, 9, 10, and Appendix S1 require strict adherence to safety regulations. The responsibility for integrating these standards into the technological process and ensuring occupational health and safety lies with the operating organization.
Technical Information and Standardization
This standard was developed and is under the jurisdiction of ASTM Committee B10 on Reactive and Refractory Metals (Subcommittee B10.01 on Titanium). The current version of standard B891 was approved on March 1, 2012. For the design of pressure-retaining equipment under ASME codes, specification SB891-12 (Section II) should be used.