This standard specifies the requirements for the design, manufacturing, inspection and acceptance of titanium welded vessels (including vessels with such members as shell made of solid titanium, titanium lined and titanium clad steel plate vessels).
1.1 This standard is applicable to titanium welded atmospheric vessels and titanium welded pressure vessels which the design pressure is no greater than 35MPa.
1.2 The design temperature range applicable to this standard shall be determined according to the permissible application temperature of titanium and titanium composite plate. The differences of linear expansibility coefficient between titanium and steel shall also be considered for the design temperature range applicable to titanium lined vessels.
1.3 This standard is not applicable to the following various vessels:
a) Directly-fired vessels;
b) Vessels in the nuclear-energy plant;
c) Compression vessel chambers as the component parts of such motive mechanical equipments with rotation or reciprocation (such as centrifugal pump shell, cylinder body of reciprocating pump, cylinder body of compressor, cylinder body of refrigerating machine, case of blower, rotating drum of centrifuge);
d) Frequently-transported vessels;
e) Vessels with internal diameter be less than 150mm (means width, height or diagonal line for the noncircular section, such as the diagonal line of rectangular or the major axis of ellipse);
f) Vessels requiring fatigue analysis.
1.4 The calculation method of various vessels elements listed in this standard is applicable to solid titanium vessels, the steel sections of titanium lined and titanium clad steel plate vessels shall be designed according to corresponding steel vessel standard, generally, the strength of titanium layer shall not be taken into account during calculation.
1.5 For the pressure elements with structural dimension not being determined using this standard, the following methods may be adopted in the design, but they shall be evaluated and approved by the National Technical Committee on Pressure Vessels of Standardization Administration of China:
- Stress analysis, including finite element method;
- Replication experiment analysis (such as experimental stress analysis and replication hydraulic pressure test);
- Comparison empirical design by using such comparable structures that have been in service.
