20929 Bridge Street, Southfield, MI 48033
4121 Brockton Drive SE, Grand Rapids, MI 49512
6200 Baron Drive, Bridgeport, MI 48722
6910 Treeline Drive, Suite A, Brecksville, OH 44141
Phone: (800) 589-6120 - Fax: (248) 354-3710
www.deppmann.com
Serving the industry since 1927
June 1st 2009 ~ Monday Morning Minutes:
Temperature of the Liquid Entering a Condensate Return Unit
There are three types of condensate return units; Pumped units vented to atmosphere such as ITT
Domestic model CC or CB, Pumped units with pressurized receivers such as ITT Domestic
model SA, and pump-less units such as Kadant Johnson Liqui-Mover®.
Most condensate return units are vented. This means if the temperature of the
condensate returning into the receiver is over 212°F there will be flashing in the receiver. There
are two concerns with higher temperature returns to vented condensate units; NPSH or net
positive suction head required and pump seal temperature limitations.
Pump seal limitations are normally 250 degrees F so for most HVAC applications
NPSH is the item of concern. In general the condensate pumps must have a low NPSH to handle
the low pressure higher temperature condensate.
Condensate Temp. °F
Pump NPSH Required
200
7
202
6
204
5
206
4
208
3
210
2
212
0
We recommend you read the ITT Bell and Gossett article about NPSH for more details
at http://www.bellgossett.com/Press/BG-NPSH2.asp#s1
The exact pump type required for the project may require specific information about the system
however as a general rule here is some suggestions.
1.
2.
3.
If the steam pressure to the heat exchanger control valve is less than 10 PSIG and the
condensate pipe is un-insulated use an ITT Domestic series CC. If the pipe is insulated use
an ITT Domestic series CB
If the steam pressure to the heat exchanger control valve is less than 20 PSIG and the
condensate pipe is un-insulated use an ITT Domestic series CB. If the pipe is insulated use
an ITT Domestic series CBE (Elevated)
If the steam pressure to the heat exchanger control valve is less than 30 PSIG and the
condensate pipe is un-insulated use an ITT Domestic series CBE (Elevated). If the pipe is
insulated use a Kadant Johnson Liqui-Mover®
In all cases remember if the condensate lifts into the receiver it must not lift above the heat
exchanger steam trap.
Thank you for using products sold by
R. L. Deppmann Company in Michigan and Ohio!
Disclaimer: R. L. Deppmann and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the information comes from many
years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions
that result from this information. Please feel free to contact us if you do have any questions.