1、 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 1 of 6 NAVISTAR, INC. CEMS (CORPORATE ENGINEERING MATERIAL SPECI
2、FICATION) NUMBER: CEMS BT-39 TITLE: Determination Of Nonabsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: August 2009 WRITTEN/REVIEWED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES ISSUE OF: October 2001 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR C
3、URRENT REVISION This specification may involve hazardous materials, equipment, and procedures. This specification does not purport to address all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices and to determine the applicabilit
4、y of regulatory limits prior to use. Change Notice: Replaced “International Truck and Engine Corporation” with “Navistar, Inc.” per corporate directive. 1.0 SCOPE This is a method for determining the volume percentage of nonabsorbable gas in air conditioner refrigerant. (This method adapted from “De
5、termination of Nonabsorbable Gas in Fluorocarbon Products”, DuPont Test Method B-38.) 2.0 APPARATUS 2.1 Special absorption vessel, No. LG-11119, available from Labglass, Inc., Northwest Boulevard, Vineland, NJ 08360. (See Figure 1, page 4.) 2.2 250 milliliter leveling bulb. 2.3 Glass tee. 2.4 Pinch
6、clamp. 3.0 MATERIAL 3.1 Distilled water. 3.2 Tygon tubing. 3.3 Reagent grade perchloroethylene (tetrachloroethylene). 3.4 “Siliclad” (silicone concentrate) obtainable from the Scientific Glass Apparatus Company, Inc., 737 Broad Street, Bloomfield, NJ 07003. CAUTION: Perchloroethylene is toxic and Si
7、liclad is both toxic and flammable. These materials must be used in adequate ventilation. 4.0 PROCEDURE 4.1 Prepare the special absorption vessel as follows: 4.1.1 wash the vessel in soap and water, and rinse in clear distilled water; 4.1.2 prepare a solution of one part by volume “Siliclad” to 100
8、parts by volume distilled water; 4.1.3 swirl the “Siliclad” solution inside the absorption vessel, completely coating the inner surfaces, allow to stand for at least 5 minutes, and then discard the excess solution; 4.1.4 rinse the vessel with clear distilled water and dry at 212 + 3F (100 + 1C) for
9、at least ten minutes: 4.1.5 the absorption vessel must be re-treated in the foregoing manner when water begins to form droplets instead of a thin film on the vessel walls. NUMBER: CEMS BT-39 TITLE: Determination Of Nonabsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: August 2009 This
10、 document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 2 of 6 4.2 After cooling the vessel, attach it to the leveling bulb w
11、ith tubing. Add 20 to 25 milliliters of distilled water to the bulb and allow it to flow into the vessel. Fill the bulb and vessel with enough perchloroethylene previously saturated with both air and water to force the water in the vessel into the stopcock stem. Make certain that the water level rea
12、ches the top of the stopcock stem. Saturated perchloroethylene may be made by bubbling undried air through it. 4.3 Add sufficient water to the leveling bulb to form a water seal in the bulb, also. See Figure 2, page 5. 4.4 Attach the absorption vessel-leveling bulb combination and the glass tee-pinc
13、h clamp combination to the sampling source with Tygon tubing as shown in Figure 2, page 5. 4.5 Close the stopcock on the absorption vessel, open the pinch clamp and purge the lines to remove residual air. Purging must be done with the sample container inverted; also, purging must be conducted at a r
14、ate slow enough to prevent the introduction of liquid refrigerant into the connecting tube. 4.6 Close the pinch clamp and then close the valve on the sample source. Return the sample container to the upright position. Open the stopcock on the absorption vessel, and then open and adjust the valve on
15、the sample source until the flow of gas is barely detectable. Care must be taken to avoid breaking the water seal when introducing the sample. 4.7 Allow the vapor to displace the fluid in the absorption vessel to a volume slightly greater than 100 milliliters. Close the sampling valve and the stopco
16、ck, and detach the absorption vessel-leveling bulb combination from the system. 4.8 Adjust the volume of the sample to 100 + 1.0 milliliters by quickly turning the stopcock to vent excess sample. This should be done under a slight positive pressure to avoid the entry of extraneous air. Positive pres
17、sure can be maintained by keeping the sample vessel slightly below the leveling bulb. Close the stopcock after adjusting the volume to 100 + 1.0 milliliters. 4.9 Tilt the vessel in such a way as to remove all of the water separating the perchloroethylene and refrigerant gas. See Figure 3, page 6. Do
18、 not allow any gas to escape into the lower chamber of the absorption vessel. 4.10 Allow the perchloroethylene to flow into the upper chamber and gently agitate the vessel to aid in the absorption of the sample gas. 4.11 After 80 to 90 percent of the gas has been absorbed, shake vigorously for 15 to
19、 30 seconds. 4.12 Return the absorption vessel to an upright position and adjust the height of the absorption vessel and the leveling bulb until both upper water layers are at the same level. 4.13 Read and record the volume of the vapor remaining in the absorption vessel to + 0.1 milliliter. 4.14 Op
20、en the stopcock and vent the remaining vapors. 4.15 Reconnect the absorption vessel-leveling bulb combination to the glass tee-pinch clamp-sampling source system. 4.16 Repeat steps 4.5 through 4.14, (pages 1 and above), except that in step 4.6 do not return the sample container to an upright positio
21、n, i.e., draw this sample from the liquid phase in the container. This second run is to compensate for the air introduced by dissolution of the air that was in the air-saturated perchloroethylene. 4.17 Approximately 35 analyses can be performed with each charge of perchloroethylene; at that point, i
22、t should be replaced with freshly saturated perchloroethylene. NUMBER: CEMS BT-39 TITLE: Determination Of Nonabsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: August 2009 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corp
23、orate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 3 of 6 5.0 CALCULATIONS Calculate the percentage of nonabsorbable gas in 100 milliliters of sample from the following equation: Nonabsorbable gas, % by weight = A-B where: A = vo
24、lume of sample after absorption when sample is drawn from the vapor phase in the container, ml (first run) B = volume of sample after absorption when sample is drawn from the liquid phase in the container, ml (second run) Since the basis of both runs is 100 milliliters, the difference between A and
25、B is also the quantity of nonabsorbable gas in percent. 6.0 REPORT Report the percentage by volume of nonabsorbable gas. NUMBER: CEMS BT-39 TITLE: Determination Of Nonabsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: August 2009 This document is restricted and may not be sent outside
26、 Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 4 of 6 NUMBER: CEMS BT-39 TITLE: Determination Of Nonabsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: A
27、ugust 2009 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 5 of 6 NUMBER: CEMS BT-39 TITLE: Determination Of Nona
28、bsorbable Gas In Air Conditioner Refrigerant CURRENT ISSUE DATE: August 2009 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2009 by Navistar, Inc. AUGUST 2009 Page 6 of 6 Fig. 3 Apparatus Arrangement for Absorption of Gases by Perchloroethylene
