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jax1
28-12-2007, 05:52 PM
Hallo,

I've mount an ICS 40 ( EVM pilot and pilot external connection on hot gas pipe) on suction line of ammonia pumped system. I want to use it for defrost cycle.

Maybe it is not the happiest solution ( I think PMLX would be better) but I've done it.

I've start up the plant and, after defrost the ICS can't open.

I think the reason are:

- dirty into the pipe
- the hot gas is not enaugh for opening the ICS

What are your opinion about it?

Tycho
29-12-2007, 01:03 AM
Hallo,

I've mount an ICS 40 ( EVM pilot and pilot external connection on hot gas pipe) on suction line of ammonia pumped system. I want to use it for defrost cycle.

Maybe it is not the happiest solution ( I think PMLX would be better) but I've done it.

I've start up the plant and, after defrost the ICS can't open.

I think the reason are:

- dirty into the pipe
- the hot gas is not enaugh for opening the ICS

What are your opinion about it?


If the pressure inside the evaporator is to high you will have no pressure difference between the hotgas line and the inside of the evaporator, that's why the valve wont open.

there is a small hole in the piston of the valve piston that bleeds the pilot pressure when the EVM closes, so the valve returns to closed position.

so if the hotgas pressure is to low you will not be able to open the valve after a defrost cycle. I had the exact same problem a few weeks ago on a new installation, I had to open the OFV valve a little bit to lower the pressure inside the evaporator, and just to be on the safe I also raised the hotgas pressure a little bit.


The main problem was when the operators left it to long between defrost and freezing, making the compressor reduce capacity.

If you mounted the damping nozzle on the EVM I would suggest you drill it up by atleast 1 mm as the normal size is the same as the bleed hole in the PM's piston, making it harder for the valve to open if the pressure difference is on the small side

Tycho
02-01-2008, 09:00 PM
How'd it go?

herman
29-08-2010, 05:28 PM
very good, indeed