Steam Trap Proximity to Heat Exchanger

[tkdhwjd]

Dear Colleagues,

I have a heat exchanger that heats up the process fluid with steam. The duty is controlled by adjusting steam side pressure. The condensate is gravity drained from the exchanger and routed to the condesate system via a steam trap. This exchanger is getting replaced with a larger sized exchanger. Unfortunately, the new exchanger must be placed at a different location due to a space constraint.

To make a long story short and without getting into facility details, we have a good reason to reuse the existing steam trap for the new exchanger. However, this will extend the distance from the exchanger to the trap quite a bit (~ 20m). Provided that there are no pockets and still allows for a gravity drain, are there any issues? Are there any industry practice regarding the distance in between a trap and a process equipment? Any comments will be appreciated.

 

[pennpiper]

tkdhwjd,
To use an old term, "This is a no-brainer".
You need to talk to a qualified and experienced Piper.
He or She will tell you that you SHOULD move the trap along with the exchanger. Keep the trap a minimum distance from the exchanger.
You are moving the exchanger so then you are rerouting the process side inlet & outlet piping. You are also rerouting the Steam inlet piping. So go ahead and move the trap and reroute the condensate side piping.

 

[Joesteam]

You have said there will be gravity drain to the trap, but is there gravity drain AFTER the trap to an atmospheric condensate return??
Anyway, if the piping to the trap is the correct size or bigger, I disagree with the previous post and do not see a problem with putting the trap further from the heat exchanger. It will allow for good separation of the steam/condensate before the trap and also add some subcooling of the condensate to give the trap a bit more capacity by reducing flashing.
In most cases it is a trap too close to the heat exchanger that causes problems....

Joe Lambert

http://www.control-associates.com/

 

[djack77494]

Closer is better, but you need to evaluate if your modifications will put your design in jeopardy. If your pressure losses (dynamic & static head) don't increase much, then I'd think your proposal should be successful. I'd be more worried about the trap's capacity if you're significantly increasing the exchanger's size.

 

[unclesyd]

Like any good steam trap installation make sure you have good built in and maintained freeze protection. The further away, the more important this is.

 

[rmw]

The farther you put the trap from the exchanger the more subcooled your condensate will be entering the trap. Depending on which type of trap that you are using, that might need to be checked out.

rmw

 

[tkdhwjd]

Thank you all for your feedbacks.
From hydraulics and trap capacity points of view, we have no issues. I wanted to see if there have been any cases where a significant distance in between a trap and an equipment has caused some problems. Thank you all for your suggestions and tips.

 

[chief]

I have always preferred siting the control valve on the outlet site of the heat exchanger , where the conditions are less onerous on the valve internals. This also reduces the possibility of having a 2-phase flow to your trap.
This of course is backed up by the normal installation of manual isolation valves at the inlet and outlet of the heat exchanger

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