Emerson VSR Manuel D’Utilisation

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Installation
Care must be taken to avoid trapping the lines ex-
cept for specifi c purposes.  When traps are used, 
the horizontal dimensions should be as short as 
possible to avoid excessive oil trapping.
Lines for ammonia systems must be of steel pipe 
with specially designed ammonia service fi ttings.  
Common pipe fi ttings must NEVER be used as 
they will not provide the same service.  Steel pipe 
is generally used in large installations when joints 
are welded.
In making up joints for steel pipe, the following 
procedures should be followed:
For threaded connections, all threads on the pipe 
and fi tting should be carefully cleaned to remove 
all traces of grease or oil.  Threads should then be 
wiped dry with a lintless cloth.  Only thread fi ll-
ing compounds suitable for refrigeration service 
should be used for making steel pipe joints.  These 
compounds should be used sparingly, and on the 
pipe only.  Do not put any on the fi rst two threads 
to prevent any of the compound from entering 
the piping system.  Acetylene or arc welding 
is frequently used in making steel pipe joints, 
however, only a skilled welder should attempt this 
kind of work.  Take care to see no foreign materials 
are left in the pipes and remove all burrs formed 
when cutting pipe.
It is important to avoid short, rigid pipe lines that 
do not allow any degree of fl exibility.  This must 
be done to prevent vibration being transmitted 
through the pipe lines to the buildings.  One 
method of providing the needed fl exibility to 
absorb the vibration is to provide long lines that 
are broken by 90° Ells in three directions.
Smaller Halocarbon and Hydroflourocarbon 
installations use copper pipes with solder type 
fi ttings where possible. The use of screw type 
fi ttings in Halocarbon systems should be held 
to an absolute minimum, as these refrigerants, 
due to their physical properties, will leak through 
screw type joints.
When drawn copper tubing is used for Halocar-
bon lines, type “K” or “L” conforming to ASTM 
B88 should be used.  Soft annealed copper tub-
ing conforming to ASTM B280 can also be used 
for tube sizes not larger than 1-3/8” in outside 
diameter.  These requirements are in accordance 
with the mechanical code for refrigeration ANSI 
B9.1-1971.  The type of copper tubing to be used 
for a given pressure is dependent on the strength 
of the copper at the design temperature.  Some 
local codes forbid the use of Type “L”.  Therefore, 
before installation, be sure to check local require-
ments.  Never use type “M” as it does not have 
adequate wall thickness to withstand the operat-
ing pressures.  In selecting fi ttings for Halocarbon 
piping, only wrought copper fi ttings should be 
used.  Cast fi ttings as used for water service are 
porous and will allow the refrigerant to escape.  
Note this exception: In larger pipe sizes, wrought 
fittings are not available.  However, specially 
tested cast fi ttings are available and these may 
be used with complete safety.
In larger pipe sizes, wrought fi ttings are not avail-
able. However, specially tested cast fi ttings are 
available and these may be used with complete 
safety.
When soldering copper tubing joints, only silver 
solder should be used for Refrigerant-22 service.  
Soft solder such as “50-50” should never be used, 
as its melting point is too low, lacks mechanical 
strength, and tends to break down chemically in 
the presence of moisture.
 A second method would be to install fl exible 
pipe couplings as close to the compressor unit 
as possible with connections run in two different 
directions, 90° apart.  These fl exible connections 
should be installed on both the high and low side 
lines of the compressor unit.
Hangers and supports for coils and pipe lines 
should receive careful attention.  During pro-
longed operation of the coils, they may become 
coated with ice and frost, adding extra weight to 
the coil.  The hangers must have ample strength 
and be securely anchored to withstand the 
vibration from the compressor and adequately 
support the pipe lines.
Water supply and drain connections, and equip-
ment using water, should be installed so all the 
water may be drained from the system after 
the plant has been shut down in cold weather.