View Full Version : info on electronic expansion valves

05-10-2010, 02:22 PM
hi there.
im in college at the moment doing the last phase of my appprenticeship,doing a project on electronic expansion valves,and how they are more efficient over normal expansion valves looking for info on the internet cant really find much if anyone has any sites i could visit id be greatful:D

05-10-2010, 05:51 PM
www.carel.com has case studies for electronic expansion valves, I would imagine Sporlan and Danfoss would also.


05-10-2010, 08:28 PM
Sporlan's educational material has a paper on EEVs

Also check their literature section for any additional data that you may need.

07-10-2010, 06:18 AM
The function of the thermostatic expansion valve (TXV or TEV) is to hold a constant evaporator superheat. When set and operating properly, the TXV will keep the evaporator active throughout its entire length. The conventional TXV is controlled by springs, bellows, and push rods. (See Figure 1.) The spring force is a closing force on the TXV. The evaporator pressure, which acts under the thermostatic elementís diaphragm, is also a closing force. An opening force is the remote bulb force, which acts on top of the thermostatic elementís diaphragm.
There is also a liquid force from the liquid line, which acts on the face of the needle valve and has a tendency to open the valve. However, this force is cancelled out when using a balanced port TXV. Working together, these forces maintain a constant evaporator superheat in a refrigeration system. There are no electronic devices associated with a conventional TXV.,..copied

08-10-2010, 06:07 AM
There is an excellant independant study done, that was published by Ashrae (not by the EXV manufacturers).
As I cannot put the link direct in this post,
Just put h t t p : / / w w w .ashrae.org/docLib/20100804 lazzarin.pdf

Good luck with you studies!

12-10-2010, 04:22 PM
cheers for the help lads got some good info,shud help me along nicely:D