1.0.1 This code is applicable to the design of heat-tracing and thermal insulation of instrument and piping for automatic control engineering of petrochemical enterprises.
1.0.2 During the implementation of this standard, it shall also meet the requirements specified in current relevant compulsory standard.
2 Terms
2.0.1 Thermal insulation, insulation
A general term of heat insulation and cold insulation.
2.0.2 Heat insulation
To reduce heat dissipated by equipments, pipings and their accessories to the surrounding environment, their external surfaces shall be covered.
2.0.3 Cold insulation
To reduce the heat in surrounding environment introduced into the interior of cryogenic equipments and pipings and prevent the resulting condensation on their external wall surfaces, their external surfaces shall be covered.
2.0.4 Thermal insulation layer
It refers to the thermal insulation material and its finished product which play a leading role in maintaining medium temperature stability.
2.0.5 Thermal insulation construction
It refers to the construction synthesis made of thermal insulation layer, dampproof layer and protective layer, etc.
2.0.6 Electrical heat-tracing
It refers to method to use electric heat-tracing belt or other electrical heating facilities to supplement the dispersed heat during the application of heat-traced object, so as to maintain the medium temperature within a certain range.
2.0.7 Maintain temperature
It refers to designing the heat-tracing system to keep the heat-traced object at a certain temperature under design condition.
2.0.8 Maximum maintain temperature
The electrical heat-tracing system is able to keep the heat-traced object at the maximum temperature continuously.
2.0.9 End termination connection
It refers to the end termination connection of the electric heat-tracing belt against the power supply end.
2.0.10 Thermostat controller
It refers to a kind of site instrument capable to inspect and control the temperature or the ambient temperature of electrical heat-tracing system. It is able to control power-on/off of electric heat-tracing belt at site and send the signal of warning contact.
3 Heat-tracing and Thermal Insulation Method of Instrument
3.1 Steam Tracing
3.1.1 Steam tracing shall be adopted in case of one of the following conditions:
1 The measuring piping, sampling piping and inspection instrument of the materials resulting phenomena such as freezing, condensating, crystallizing and precipitating at ambient temperature.
2 The occasion in which the minimum requirement of ambient temperature is not able to be met.
3.2 Hot Water Tracing
3.2.1 Hot water tracing shall be adopted in case of one of the following conditions:
1 The occasion in which the steam tracing should not be adopted;
2 The occasion without vapor source.
3.3 Electrical Heat-tracing
3.3.1 Electrical heat-tracing shall be adopted in case of one of the following conditions:
1 The occasion requiring remote control and automatic control to heat-tracing system;
2 The occasion requiring higher environment cleanliness.
3.4 Thermal Insulation (Heat Insulation and Cold Insulation)
3.4.1 Thermal insulation by means of heat insulation shall be adopted in case of one of the following conditions:
1 Instrument inspection system for hot fluid (such as vapor, hot water or other high temperature materials);
2 The inspection system capable to guarantee the normal operation of instrument and piping with thermal insulation by means of heat insulation;
3 All occasions requiring heat-tracing;
4 Steam or hot water piping, condensation return piping and electric heat-tracing belt etc. for heat-tracing.
3.4.2 The instrument inspection system for cold fluid shall be adopt with thermal insulation by means of cold insulation.
