Pipework Installation - Marstair A2LSYSTEMATCH SMC 15 Technical Manual

2D PIPEWORK INSTALLATION.
Supplied Sweat connections
Model
Size
Expansion
Suction
The installation section of the risk assessment template or equivalent should be carried out before commencing
installation.
When installing a split refrigeration system, all interconnecting refrigeration pipework must be manufactured, jointed,
tested, insulated and installed in such a way as to ensure that damage cannot occur during normal, service and
maintenance operations that may cause a rupture and subsequent leakage.
It is advisable, wherever possible, that brazed or permanent mechanical joints are used when jointing refrigeration
pipework designed for an A2L refrigerant.
MAXIMUM PIPE RUNS
80m maximum including 20m lift (50m SMC 15-20). There will be no significant loss of capacity for extended pipe runs
provided pipes are correctly sized.
CALCULATING EQUIVALENT LENGTHS
The effects of bends and fittings must be taken into account.
Pipe sizes are based on:
Minimum of 2.5 m/s (500 fpm) suction gas velocity for horizontal or downflow.
Minimum of 5.0 m/s (1000 fpm) suction gas velocity for upflow.
Maximum of 20.0 m/s (4000 fpm) suction gas.
Where vertical risers exceed 3m, oil traps must be formed in the pipe. This will help ensure that oil returns to the
compressor. Typically fit an oil trap every 3m with a trap at the bottom of the riser.
GOOD PRACTICE
Keep pipe runs as short as possible.
Avoid sharp bends
Fully insulate both suction and expansion lines including mechanical connections
Try to avoid running pipes through hot areas.
SMC 3/8" 1/2"
15 7.5 30
20 7.5 23
30 15
40 10
45 10
50 7.5
80
90
100
1. Connecting the pipework:
a. Release the nitrogen holding charge by slowly opening the valves using a 5mm or 8mm allen key.
b. Ensure the suction line is fully insulated.
c. Connect the pipework between the units. Do not leave pipes ends, valves etc open to the atmosphere.
d. Use a protective shield to avoid scorching the side panel.
15 20
3/8 3/8
3/8 1/2
Suction pipe size
5/8" 3/4" 7/8"
50
50
50 80
36 80
36 80
18 50 80
11 30 80
10 25 55
7.5 22 45
SMC
30 40 45
3/8 3/8 3/8
1/2 1/2 1/2
Expansion pipe size
1-1/8" 1/4" 3/8"
50
50
50
7.5
7.5
7.5
80
80
9
55008432-02
50 80
1/2 1/2
1/2 5/8
1/2" 5/8" 3/4"
80
80
80
50 80
50 80
20 80
15 80
90
1/2
5/8