R016600x

Section III - Clayton Feedwater Pumps & Water Systems

Table 3-3: Feedwater Receiver Connections

Drain

A valve must be provided in the drain line. As indicated above, the drain line can be tied into the overflow line as long as the line size downstream of the merge remains at least the size of the overflow connection on the tank. NOTE

The Feedwater Receiver drain and overflow lines (run independently or tied to- gether) may contain up to 212° F (100° C) water and must be routed to the Blow- down Tank discharge piping at a point prior to the temperature valve sensor.

Condensate Returns, Temperature Control

The condensate return connection is the point where all system condensate returns, separator trap discharge, and heating steam are introduced. The Hotwell may use one or two condensate return connections, depending on the tank size and return volume. This injection point is located below the water line and connected to a sparger tube(s). Introducing the steam and hot condensate below the water line in conjunction with using the sparger tube reduces the velocity and turbulence created at the injection point, while minimizing flash steam losses and noise. On tanks containing two condensate return connections one is used for system condensate returns, the other is used for the separator trap discharge and heating steam. In all cases, a check-valve must be installed in the separator trap discharge, condensate return, and steam supply lines, to prevent back-feeding. The check-valve must be located as close to the feedwater tank as possible. When installing a Sparger Tube(s) it must be installed so that the holes are in a horizontal position. This is confirmed on Clayton manufactured Hotwells (up to 200 bhp) by visual verification that the “X” stamping on the external section is in the “12 o’clock” position. Refer to Drawing R-16099 for the proper temperature control valve configuration.

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Sparger Tube(s)

NOTE Clayton feedwater receivers are sized for proper flow and chemical mixture. If a customer’s condensate system creates large surges in returns at start up or while in operation, it may cause the feedwater receiver to overflow. Proper evaluation of the condensate return system and final feedwater receiver sizing is the customer’s responsibility.

3.5 DEAERATOR (D/A)

(Refer to P&ID Drawing R-16595.) Effective control of the pressure in the deaerator is essential to proper performance and operation of the Clayton steam generator system. Most deaerators have high and low pressure condensate return inlet connections. The high temperature condensate should be introduced into the D/A through a sparger tube. Condensate returns affect the pressure and water temperature in the D/A. Introducing condensate return increases the pressure in the D/A and, conversely, reducing the amount of condensate return decreases the pressure in the D/A.

3-5

07/10/2015

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