5800 Refrigerated Sampler Service Guide - Isco

5800 Refrigerated Sampler Service Guide
Section 3 Refrigeration System
Refrigerant dryer
If a leak is repaired, replacement of the dryer is recommended.
Figure 3-10 Refrigerant dryer, before and after installation and coating
Orifice
Refrigerant leaks
The precision orifice through which liquid refrigerant changes
temperature and pressure before entering the evaporator coil is a
very delicate device, and is easily clogged. It is therefore critical
to prevent anything other than refrigerant from entering the
system, such as solder flux particles, water, or oxidized copper. If
the orifice becomes clogged or otherwise damaged, replacement
of the refrigeration module is recommended, due to the likelihood
of a new orifice becoming clogged with flux during the brazing
process.
Leaks are most likely to occur in the locations indicated by
arrows in Figure 3-11. A leak near the dryer or orifice is likely to
be caused by a drastic difference in temperature and pressure on
either side of the orifice. Other leaks may have been caused
during shipping or other physical shock.
Repair leaks with refrigeration-grade copper tubing, brazing the
ends with silver solder and properly covering all joints and
exposed metal from corrosive elements.
WARNING
Do not run the compressor during evacuation, leak testing,
or charging.
3-14