NH3 Piping

[CHIEF DELPAC]

Help I need help. My employer is going to build a large chill room. The problem is that the building is about 300 feet from the Engine Room. The chill room will require a nh3 liquid line and a nh3 suction line. Due to traffic and storage areas the lines cannot be placed in the air between the Engine Room and the new chill room building. There is a proposal from the contractor to bury the lines in the ground to route them between the buildings. I have never heard of putting nh3 refridgeration lines underground. I am wondering if its feasible? I would like to hear from anybody who has experiance on underground refrigeration lines.

[Magoo]

Hi Chief Delpac.
I have seen them in trenches with removable concrete covers for access, similar to steam lines etc..

[CHIEF DELPAC]

Thanks Magoo For some reason [ old age I guess] I was thinking that the lines would be buried like water and sewer lines

[Josip]

Hi, CHIEF DELPAC

Help I need help. My employer is going to build a large chill room. The problem is that the building is about 300 feet from the Engine Room. The chill room will require a nh3 liquid line and a nh3 suction line. Due to traffic and storage areas the lines cannot be placed in the air between the Engine Room and the new chill room building. There is a proposal from the contractor to bury the lines in the ground to route them between the buildings. I have never heard of putting nh3 refridgeration lines underground. I am wondering if its feasible? I would like to hear from anybody who has experiance on underground refrigeration lines.

In SA I was working for one huge cold store. Engine room was far away from different temperature cold rooms, tunnels ... do not remember the distance (I'll try to check in my documents and drawings) and the build a underground tunnel for all liquid and suction pipes (OK, they had a few temperature systems and that is the reason to have more pairs of pipes). They use that tunnel also for cables and water pipes. Anyhow you need to assure oil drain from suction pipe and possibility for complete evacuation of your underground pipes. Tunnel sounds expensive, but at the end, maybe, it is not.

Best regards, Josip

[Quality]

I have been on a few jobs and installed pipes through what we called troughs which is basically a path/trench in the floor which has removable access. All made from fibre resin or concrete

[CHIEF DELPAC]

Hi Josip Yes oil will be a problem. I would think that an oil separator or oil pot or ? will be needed. I guess the best place would be down stream from the evaporator also close to the evap. Thanks C.D.

[D.D.KORANNE]

1) oil is not miscible with nh3 & oil is heavier than liquid ammonia therefore it (oil) will settle in traps ,u bends and other places wherever it can collect in such places. oil separator should be efficient in such systems and installed at a distance away ( as far as possible) from compressor for better separation as it will allow time to condense in case it becomes vapor

2) another method is to go in for (ammonia) liquid pump circulation .

[Magoo]

Hi Chief Delpac.
definitly concider stainless steel schedule 10 pipe. Obviously more expensive, but no corossion issues down the track.

[josei]

With a long distance as 100 m (300 feet) , a solution w´d include:

A pumping system of NH3 with steel pipe by tunnel .

For prevention with a place to drain the oil in the pipe buried but the main point of oil recovery is in the recirculation unit.

Periodical inspections of the state of the pipe and insulation

[mbc]

I done it before,
it was about 100m distance and 2 meter under ground in duct . and rooms size were 4 room 12X12x5 meter
main thing your pipe should have slop and oil drain system from suction line .