ParaFlow SOLUTION SAMPLING

PROCEDURES

SERVICE Supersedes: 155.17-SA1 (595) Form 155.17-SA1 (397)

PLEASE READ COMPLETELY THE FOLLOWING INSTRUCTION BEFORE

TAKING A SAMPLE FOR LABORATORY ANALYSIS 3. If a unit has recently been de-crystallized, do not
sample it until it has run at least 8 hours without any
Suggested Tools and Materials signs of crystallization.

Spindle Valve Adapter 4. Remove the sample from the main solution pump (P1)
Allen Wrench (Metric - 10 mm) discharge sampling valve. This point should be in a
Barbed Fitting (1/4" barb x 1/2" MPT) positive pressure when the pump is running, although
Hydrometers it is always best to prepare the sampling flask as
Clear Vacuum Hose (YORK p/n 028-12514-000) though a vacuum is present. Do not allow air to en-
Hose Clamps ter the unit!
Protective Face Shield and Gloves
Solution Sample Kit 5. Before taking the sample, put the unit into a dilution
(Order from Analysts, Inc. - 800-222-0071 cycle and blow down the refrigerant so that the sample
Silicone Vacuum Grease (Dow Corning) is as dilute as possible. Allow the dilute solution to
Plastic Bucket (2-5 gal) circulate for a few minutes before taking the sample.
Hydrometer Flask (150 ml) Samples taken with high concentrations have been
Pipe Sealant (Loctite 567 and Primer N) found to be more prone to inaccuracies and they may
Loctite Cleaner 7070 crystallize en route to the lab. Crystallized sample will
Vacuum Flask not be accepted by the lab.
Small Plastic Funnel (50 ml)
Do not submit solution samples with concentra-
tions in excess of 55%.
CAUTION: When taking samples, wear a full face shield,
protective gloves and apron to avoid the dan- 6. Always wash out the sample apparatus with at least one
ger of hot solution splashing on the skin or sample before taking the actual sample for analysis.
eyes. Do not use glass sample flasks. Use
polypropylene or other vacuum suitable, labo- 7. Do not use copper or brass fittings when taking samples.
ratory grade plastic containers.
8. Use clean, plastic (polypropylene or nalgene) contain-
ers to draw and handle solution samples. Do not use
To take a solution sample for lab analysis, it is very im- glass.
portant to get a representative sample from the unit. In-
correct sampling techniques could lead to a sample that 9. Generally speaking, for preventive maintenance pur-
is not a true indicator of the system chemistry. poses, two samples should be taken on each unit per
year. One at the beginning of the cooling season and
Strict adherence to the following rules when taking a one near the end. After chemical corrections are made
sample for lab analysis is strongly advisable. to a unit, resampling should be done as necessary.

1. The unit should be running in the cooling mode for at

2. New units or units where chemicals have recently been In order to take a sample from any sample point on the
added should be allowed to run until the purging of unit, it is necessary to connect a sample flask using the
non-condensables has subsided (this may take a week proper fittings and suitable vacuum tubing.
or more) before resampling.
Be aware that if the unit is equipped with spindle-type tem. Its purpose was to wash out the sample apparatus
valves for sampling (all USA built ParaFlow units have and flush the sample valve. Never use the first sample
spindle-type sampling valves), you must use a special drawn.
spindle valve adapter fitting. The spindle valve has a spe-
cial internal straight thread. If you screw in a 1/2" pipe Re-install the sample flask and repeat the above proce-
nipple, it may appear to work; however, it will leak and dure.
possibly damage the internal valve threads.
Using an accurate thermometer, measure the tempera-
Never assume that a sample point is in a positive pres- ture of the second sample. Gently stir the thermometer
sure. Units will vary. Although on most G Model units it is in the solution until the temperature stabilizes. Record
normal for the main solution pump (P1) discharge to be the temperature. Select a hydrometer that is in the cor-
in a positive pressure, this is only the case when the rect density range of the sample liquid. Normally, this will
pump is operating and turning in the correct direction. be the 1.600-1.800 hydrometer. Carefully read the spe-
cific gravity of the liquid and record it. Using the solution
Evacuate the sample flask to a pressure lower than the tables, find the concentration equivalent to the specific
sample point so that the solution will flow into the sample gravity and temperature of the sample. It should be less
flask and air will not enter the unit. To do this, you may than 55% for lab analysis purposes.
use the unit purge pump or a separate vacuum pump if
one is available. When using the unit purge pump, install Remove the two sample bottles and one piece of the
a tee and an isolation valve between the manometer and filter paper from the Solution Sample Kit. Fill the larger of
the purge piping. The manometer is used as the vacuum the two bottles (4 oz.) with the solution from the hydrom-
indicator when evacuating the sample flask. Since acci- eter flask. Replace the cap tightly.
dents do happen, it is a good idea to install a trap of
some kind between the sample flask and the manom- Using one piece of the filter paper, fold it into quarters so
eter. The refrigerant removal tank may be used for this that it fits into a small funnel. Place the funnel into the
purpose. When connecting hoses to fittings, the use of smaller sample bottle (2 oz.) from the kit. Pour solution
vacuum grease will ease installation and help prevent air from the hydrometer flask into the filter paper in the fun-
leaks. nel and carefully allow the smaller bottle to fill with fil-
tered solution. This may take some time. When the bottle
After completing the tubing connections to the sample is nearly full, replace the cap, insuring it is tight.
flask, open the valve to the flask and any isolation valves
between the flask and the vacuum source. Evacuate the Be sure both bottles have a tracking number label on
flask to 1-3 mm Hg absolute. Slowly open the sample them and that the tracking number matches the label on
valve until solution or refrigerant begins to flow into the the “Sample Submittal Form,” Form 155.17-RA1 (397).
flask. Hold the sample flask so that the incoming solu-
tion does not exit the flask through the vacuum connec- Carefully fill out the “Sample Submittal Form” completely,
tion. As the sample flask fills up, it is normally possible making sure that all data is printed in a legible fashion.
to close the valve on the vacuum connection to the flask The unit serial number is the tracking identification for
and then close the unit sample valve. It is not important future trending of analysis data, so it is very important
what order the valves are closed in, but it is very impor- that the number is totally correct.
tant to avoid introducing air into the unit or sucking solu-
tion into the vacuum pump. After ensuring that the sample Keep the yellow and pink copies (the pink copy may be
valve is completely closed, remove the sample flask. To given to the customer) of the Sample Submittal Form
break the vacuum in the sample flask, hold the flask and put the original white copy of the form with the
upright and slowly open the valve on the vacuum con- tracking number label that matches the bottles back
nection of the flask. Pour the contents into a hydrometer in the Sample Kit Box along with the two samples. Be
flask. Empty the contents of the hydrometer flask into a sure the laboratory address label is on the outside of the
bucket. This solution may later be returned to the sys- box. Seal the box and mail it immediately. Postage is not
prepaid.

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P.O. Box 1592, York, Pennsylvania USA 17405-1592 Subject to change without notice. Printed in USA
Copyright © by York International Corporation 1997 ALL RIGHTS RESERVED
Form 155.17-SA1 (397)
Supersedes: 155.17-SA1 (595)