R020932J1, Install Manual

Steam Generator & Fluid Heater Installation Manual

The deaerator should be installed horizontally. The higher the DA can be elevated above the booster pump(s) the less sensitive the feedwater delivery system will be to pressure variations. Other factors, such as friction loss in the feedwater supply line and the Net Positive Suction Head (NPSH) characteristics of the booster pump(s), should be considered when planning the deaerator installation. Clayton requires booster pumps for most DA installations. The deaerator can be insulated to maximize heat retention. Descriptions for the water treatment and accessory components are provided in Section VII (Optional Equipment) and in the Clayton Feedwater Treatment Manual.

NOTE All piping to and from the deaerator must remain the same size or larger than the tank connection. Always check feedwater pump pipe size requirements and follow the larger pipe size. See Table 3-4 below and the feedwater supply re- quirements and pipe sizing guidelines discussed in Sections 2.8, 2.9, 2.10, and 2.11.

Table 3-4: Deaerator Connections

Feedwater Outlet

This connection is used to deliver properly treated feedwater to the booster pump(s) it is typically on the bottom of the tank. A valve and strainer must be provided in the feedwater supply piping at the inlet to each pump. The feedwater line must be constructed so as to provide the required NPSH to the feedwater pump inlet. Restrictions in this line will cause water delivery problems that result in pump cavitation and water shortage problems in the heating coil. Feedwater line must be constructed to provide the required NPSH, velocity under 1 ft/s, and acceleration head losses less than 0.5 ft/ft to the feedwater pump inlet. Do not insulate this line. Cooling in the pump suction line is beneficial during periods of fluctuating pressure in the deaerator. See Section 2.10. A pipe tee should be installed in the feedwater outlet line just below the feedwater outlet connection. On an elevated DA System, this pipe tee provides a connection for the gravity fill plumbing. On a receiver system which uses Booster Pumps, install a pipe plug in the gravity fill tee connection. The deaerator must vent the liberated gases to be effective. Some steam is always vented with these gases. One common feedwater chemical injection connection is provided into which all feedwater treatment chemicals are introduced. A check valve must be installed in the discharge line of each chemical pumping system. No valves are to be installed in the overflow trap piping. The overflow trap piping must be plumbed to the blowdown tank discharge piping at a point prior to the temperature valve sensor. A drain 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.

Gravity Fill

Vent

Chemical Injection

Overflow Trap

Drain

3-6

Sect03_FeedwtrSys_SF_g.fm

07/10/2015