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Hi all
Good day,
i do not know where to post this question. 12 years ago someone shared following link danfoss
404 - File or directory not found. (danfoss.com)
where we can see product animation that working principle .
now link not working and i also tried to find on danfoss site but found.
please any one help to get that
thanks
Shaaf,
Are you looking for something in particular?
I’m sure still out there.
Are you looking for the two step GPLX/PMLX?
I see from the URL you linked to that it's called PMLX, but danfoss has evolved and the new valve is now called the ICLX
https://www.youtube.com/watch?v=TqjJEG-eLCc
from the first evolution, I believe was the GPLX :)
The two step suction valve, and I absolutely loved it after having seen it in action on a freezing tunnel 10 years ago.
they had a freezing tunnel that were to auto hotgas defrost every 20 hours.
GPLX valve on the suction, and an EVRA 20 and an EVRA 40 on the hotgas.
Hotgas defrost cycle would start with GPLX closing, then EVRA 20 open first for 30 seconds to build up pressure and start pushing liquid out through the OFV, then bam, the EVR 40 would open and give full flow of hot gas.
Once that cycle was done, the IQF freezing tunnel would be at 6-7 bar, and then it were to start freezing again, and it had to go through the GPLX 100 valve.
I have to say, I were scared when I first tested it, but it went "click" and I heard like "sssssssssss" and I watched the pressure gauge as it went down from 7 bar and down to 1.5 bar and at 1.5 bar the valve said *Clonk* and were full open and it was on a freezing cycle again :)
I were sold, best damn automatic suction valves ever :D
I were part of a rebuild on a ship after a fire, and sold in GPLx valves we had as a prototype in stainless, but they have internal leaks, so we have to replace them with ICLX valves on warranty... but still, the two step suction valve from Danfoss is gold in plant automation :)
Tycho,
The GPLX has caused issues over the years when servicing.
People put together incorrectly, always washer in the wrong spot.
Only used on one job before IPLX hit the market.
PMLX/ICLX time delay required for closing, can be overlooked if you don’t read instructions of course.
NO & NC solenoids also can be overlooked for the inexperienced whom also don’t read to well.
Hi Tycho
Thanks for your input and others too. I found many vids on YouTube but not available on danfoss site.
2nd question is 2 step valve is compulsory for auto defrost ?
Shaaf,
Not compulsory, but recommended.
Previous to this style of valve would be a smaller solenoid to equalise pressure around suction solenoid valve.
This is to stop liquid hammer in pipe work & general smoother operation.
1. Because here in our plant, PM40 is installed at the suction line (-42 degrees Celsius) with pilot valves S1 solenoid valve and S2 CVP (set on least pressure. During the cooling mode, PM40 does not function properly, so all 6 cold stores are continuously opened with a manual spindle for smooth operation.
2. Is it necessary to open PM40 with a suction temperature of -42 degrees 2-step valve function required?
Thanks
Shaaf,
With-42 suction normally have hot gas to drive open valve to reduce pressure drop on cooling mode.
S1 hot gas connection
S2 EVM solenoid normally closed.
P CVP. For pressure regulation when on hot gas defrost set 515 kpa or about +10. depending where your hot gas defrost is relieving (liquid or suction).
Shaaf,
With-42 suction normally have hot gas to drive open valve to reduce pressure drop on cooling mode.
S1 hot gas external connection
S2 EVM solenoid normally closed.
P CVP. For pressure regulation when on hot gas defrost set 515 kpa or about +10. depending where your hot gas defrost is relieving (liquid or suction).
https://haphillips.com/wp-content/up.../PDHL0A122.pdf
https://assets.danfoss.com/documents...7en-000704.pdf
Check hot gas page 54 onwards
https://www.danfoss.com/en/about-dan...s-application/
Hi Ranger Sir,
I'm extremely grateful for your assistance. Thank you!
Can an EVM NC function properly if it is installed sideways instead of vertically?
Shaaf,
Can be mounted horizontal, or vertical.
Also find some further information on pilot valves
AN259252731157en-000101.pdf (danfoss.com)
AI248786497190en-000801.pdf (danfoss.com)
Because my previous company has six cold stores operating at a suction temperature of -42°C, they installed a PM40 at suction line one with a pilot valve EVM NC. However, during normal operation, the PM does not fully open, so they manually adjust the spindle to keep it open. Is it necessary for them to have a hot gas-powered pilot valve EVM NC/EVM NO system?
Shaaf,
You could probably get away with hot gas powered PM valve with Danfoss orifice that can be screwed into bottom of EVM.
The only issue you might have is that you normally need a PM3-40, so you have extra ports in valve top.
These valve tops are no longer available from Danfoss I believe.
If you do not have PM 3-40 then you can use a CVH pilot EVM NC solenoid feeding into top of PM 1-40.
EVH page 14
https://assets.danfoss.com/documents...0en-000801.pdf
PM 1 page 8 external connection (can be used with EVM/CVH
https://haphillips.com/wp-content/up.../PDHL0A122.pdf
Ranger1
sorry for missing some info yes that is PM 3-40 EVM NC(s1) CVP LP(s2) set at minimum pressure.
port P blinded.
Shaaf,Quote:
Originally Posted by shaaf
So you need a hot gas supply at PM valves, each valve external connector in S1, EVM NC in S2 & CVP in P port set about 700kpa or higher for over pressure protection.
Sounds like hot gas relief in liquid line, so suction could be set at maximum 700 kpa.