1 Principle for determining design pressure and temperature of equipment
1.0.1 Scope of responsibilities
1.0.1.1 The process system specialty shall be responsible for determining the design pressure of vessels, towers and heat exchangers (hereinafter referred to as equipment or vessels).
1.0.1.2 The process system specialty shall determine the design pressure of equipment in an economical and reasonable way on the basis of meeting the safety requirements.
1.0.1.3 The process system specialty shall determine the design pressure of the vessel based on the maximum pressure that might be reached at the top of the vessel under normal working conditions provided by the chemical process specialty and the additional system conditions that shall be considered by the specialty (such as the change of system pressure and the influence of the relative position of the safety valve in the system on the design pressure).
1.0.1.4 The process system specialty shall, together with other relevant specialties such as chemical process specialty, determine the design pressure (the design pressure is higher than that determined according to Table 1.0.4) of the following equipment under the following special circumstances according to the specific conditions and special requirements:
(1) The case where discharge of highly toxic substances is restricted by the environment or directly affects the personal and environmental safety;
(2) The case where asphalt, paraffin, phthalic anhydride and other condensable materials or some slurry will solidify in the safety device and discharge system when discharged; and the case where water or other materials may freeze during discharge and thereby block the discharge system;
(3) The case where some precious materials are involved and loss due to emission is required to be reduced;
(4) The case where working pressure may rise sharply due to chemical reaction or other reasons.
1.0.1.5 If necessary, the process system specialty shall put forward the design pressure and temperature of equipment components according to the working conditions provided by the chemical process specialty.
1.0.1.6 The design temperature of equipment is not determined by process system specialty, but the normal or maximum (or minimum) working temperature of equipment during normal working process shall be put forward by the process system specialty to the equipment specialty according to the data issued by the chemical process specialty, so that the equipment specialty can determine the design temperature of the equipment. If the design temperature of equipment is required to be proposed by the process system specialty, the process system specialty may determine the design temperature according to those specified in 1.0.8.
1.0.2 Noun explanation
1.0.2.1 Pressure
Unless otherwise specified in this standard, the pressures are absolute pressures.
1.0.2.2 Maximum working pressure
maximum pressure that may be reached at the top of the vessel during normal working process, also called maximum normal working pressure, which is usually put forward by chemical process specialty
(1) Internal pressure vessel
maximum pressure that may be reached at the top of the vessel during normal working process
(2) Vacuum vessel
maximum vacuum degree that may be present at the top of the vessel during normal working process
(3) External pressure vessel
maximum internal and external pressure difference that may be reached at the top of the vessel during normal working process
1 Principle for determining design pressure and temperature of equipment
2 Principle for determining design pressure and temperature of pipe
