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STEAM GENERATOR & FLUID HEATER INSTALLATION MANUAL

Table 3-4: Deaerator Connections

Safety Relief Valve

Each deaerator is equipped with a safety relief valve to prevent overpressurizing of the tank. This valve is typically rated at 50 psi. The safety relief valve must discharge to atmosphere and in a direction that will not cause harm to personnel or equipment. The discharge piping must not contain any valves or other obstructions that could hinder the release of steam. A back pressure regulator is used to help maintain a steady operating pressure in the D/A. This valve is set below the safety valves and will vent during minor periods of over pressurization. NOTE BPR sensing line must be plumbed directly to D/A pressure sensing port at the gauge connection on top of the D/A tank.

Back Pressure Regulation Valve

3.6 SEMI-CLOSED RECEIVER (SCR) Semi-closed receiver systems are used only in applications that return a large amount (typically > 50%) of high pressure, high temperature, condensate. The SCR is a pressurized vessel that is maintained at a pressure that will minimize venting (wasting) of the excess system heat contained in the hot conden- sate returns. Feedwater outlet line sizing is critical. See Section 2.10. Each semi-closed receiver system is unique and requires individual attention to ensure proper application, installation and operation. Due to the nature and selected use of SCR systems, the system details are addressed in Supple- ment I - SCR, pages SI-1 through SI-4. 3.7 SEMI-CLOSED RECEIVER SKIDS These skids must be shipped with the SCR tank loose. Tank and interconnecting piping must be assembled by the installer. See Supplement I - SCR (pages SI-1 through SI-4) for detailed information. 3.8 HEAD TANK A 10-gallon head tank is required when proper receiver tank elevation is unavailable. A head tank provides the necessary positive coil feed pressure during wet layup. The tank must be installed at least two (2) feet above the steam generator coil inlet connection.

3-8

Sect03_FeedwtrSys_xx4_g.fm

07/10/2015