The colder medium goes in the bottom on one of the two sides (generally the right). As it is warmed, it comes out the top right side. The medium being cooled (warmer water) goes in the left top side and comes out the bottom left side. So it is counter-flow. This makes sense as water columns being warmed tend to rise and those being cooled tend to fall.
How about the valves included? Whats the idea of putting a 3-way valve in the piping connection for HE. Is there any benefit for this. How about double regulating valve. Btw the system is HOT WATER SYSTEM for AHU's.
Isoltion valves are a must for maintenenace. Provide at least an additional space for 20% more plates if needed in the future. Provide space to pull the plates so they can be cleaned.
Never used a double regulating valve on this system. Im assuming you have a glycol HW coil, and the system is not glycol, hence the reason for the HX.
Another thing to look into is the fouling factor. 3-way valves may help in keeping full flow to minimuze fouling.
I think the OP's question is too general. There are too many personal preferences on how things "should" be connected for there to be a one-size-fits-all schematic. I imagine the members of this forum could come up with at least 50 schematics that would be different in some way.
The OP provided no details about the application: Is there steam on one side? How big is the piping? Is the question about welded-plate heat exchanger?
Better to ask a specific question, such as: is it necessary to use eccentric reducers if they are in the horizontal pipes to the inlet connections? There may be a variety of answers pro and con, but it would focus the discussion and demonstrate that the OP looked at a few on-line resources before asking an unanswerable question.
To be honest I just want to get an idea from forum members regarding the proper piping connection of HE to verify the work that we had done on our site because I am being question why is that I did not install 3 way valve on the system and how could we control the temperature w/o the 3 way valve.
Actually we have two systems having a separate H.E. that have the same questions, (1) is for HOT WATER SUPPLY FOR AHU'S and (2) for DOMESTIC HOT WATER SUPPLY FOR THE BLDG. Both system will received water having a temperature of 155 deg cel. from a main line to the hot side of H.E. Now the only valves that we install are gate valve & strainer on entering supply while on the leaving are gate valve & double regulating valve with flow switch.
I just need a reference so that I can defend the work that I have done.
Pls. read my earlier post. If it's hot-to-cold, the hot should go in the top of one side and out the bottom of the same side and the cooler medium should go into the bottom of the other side and out the top of the other side.
There should be a two-way or three-way valve on the primary side that regulates based on the secondary side temperature.
Why are the heat exchangers installed? If they are only to separate a 15 psi steam boiler from water systems operating at higher pressures, maybe no controls are needed at the heat exchanger.
