СНиП на английском языке SNiP 2.04.07-86
3.11. Systems for condensate collection and return to the heat source shall be closed, and excess pressure in condensate collection tanks shall be at least 0.005 MPa.
Open condensate collection and return systems may be provided if the condensate return rate is less than 10 metric ton/h and the distance to the heat source is less than 0.5 km.
3.12. A refusal to provide complete condensate return shall be justified.
3.13. Condensate return from consumers shall be ensured by excessive pressure downstream
of the steam traps or, where pressure is insufficient, by installing condensate collection tanks and condensate transfer pumps for one or a group of consumers.
3.14. Condensate may be returned by steam traps through the common network when the steam pressure difference upstream of the steam traps is 0.3 MPa or less.
If condensate is returned by pumps, the number of pumps delivering condensate to the common network is not limited.
Parallel operation of pumps and steam traps for condensate return from steam consumers to the common condensate network is not allowed.
3.15. Discharge condensate lines shall be designed for the maximum hourly condensate flow rate, based on the condition that the total pipe diameter is used for all condensate return modes and the pipes are not empty during condensate return interruptions. Condensate return network shall have excessive pressure under all conditions. Condensate return lines from steam traps to condensate collection tanks shall be designed with allowance for steam-water mixture formation.
3.16. Specific pressure friction losses in condensate return lines downstream of the pumps shall be assumed to be 100 Pa/m or less.
Condensate return lines downstream of the steam traps shall be designed based on the difference between the pressure downstream of the steam traps and the pressure in the condensate collection tank (or in the expansion tank) with allowance for the condensate level.
Equivalent roughness of the condensate return line inside surface shall be taken as 0.001 m.
3.17. The capacity of condensate collection tanks shall be equal to at least ten maximum condensate flow rates. At least two 50% tanks shall be provided for around-the year operation; a single tank is permitted for seasonal operation and for maximum condensate flow rates below 5 MT/h. If condensate quality monitoring is required, at least three tanks shall be provided, each of them shall have capacity allowing to analyze all required condensate properties during the required time (Clause 3.20), but not less than 30 minutes of maximum condensate intake.
3.18. Condensate pump capacity shall be determined by the maximum hourly condensate flow rate. Pump head shall be determined based on the condensate line pressure loss with regard to the condensate lift from the pumphouse to the collection tank, and the excessive pressure in the collection tanks. Pump head for pumps discharging condensate to the common network shall be determined with regard to their parallel operation conditions at all condensate return modes. Each pumphouse shall have at least two pumps one of which is backup.
3.19. Routine or emergency condensate discharge into a storm or domestic drainage system is permitted after cooling it to 40°C. Condensate does not need to be cooled if discharged into an industrial drainage system continuously receiving effluents.
3.20. Condensate returned from consumers to the heat source shall comply with the Rules for Operating Electric Power Plants and Networks of the USSR Ministry of Energy.