GOST 22974.14-90
GOST 22974.14−90 fused welding Fluxes. Method of determination of moisture content
GOST 22974.14−90
Group B09
STATE STANDARD OF THE USSR
FUSED WELDING FLUXES
Method of determination of moisture content
Melted welding fluxes. Method for determination of moisture content
AXTU 0809
Valid from 01.01.92
to 01.01.97*
_______________________________
* Expiration removed by Protocol No. 7−95
The interstate Council for standardization,
Metrology and certification (I & C N 11, 1995). -
Note the manufacturer’s database.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of heavy machine building
DEVELOPERS
P. L. Babushkin, V. Y. Persits, Y. A. Margolin (leader), B. O. Zelenova, S. S. Ognianik
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from
3. INTRODUCED FOR THE FIRST TIME
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced | The partition number |
| GOST 4204−77 | 2 |
| GOST 4328−77 | 2 |
| GOST 5538−78 | 2 |
| GOST 9147−80 | 3 |
| GOST 22974.0−85 | 1 |
| GOST 24104−88 | 2 |
| THAT 6−09−3880−75 | 2 |
| THAT 6−09−4010−75 | 2 |
| THAT 6−09−5382−88 | 3 |
This standard specifies a gravimetric method for the determination of mass fraction of moisture from 0.01% to 1.0% in welding fused fluxes.
The method is based on heating in a tube furnace at a temperature of 1000 °C in flowing oxygen analyte, turning the contained hydrogen in the moisture and its gravimetric determination after absorption of magnesium perchlorate (angerona). To prevent errors of analysis of the evolved gaseous compounds of fluorine are absorbed by the lead monoxide at the exit of the tube.
1. GENERAL REQUIREMENTS
General requirements for method of analysis — by 22974.0*.
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* On the territory of the Russian Federation GOST 22974.0. — Note the manufacturer’s database.
2. APPARATUS, REAGENTS AND SOLUTIONS
Setup for determination of moisture (Fig.1) consists of the oxygen cylinder (1) according to GOST 5583, equipped with a pressure reducing valve start-up and adjustment of a current of oxygen; reducer pressure gauge 2 — fine adjustment of oxygen; safety bulb 3, which in case of overpressure in the combustion chamber prevents the ingress of sulfuric acid in the rubber tubing connecting the device with a reducing valve; the system of cleaning and drying the oxygen; wash flask 4 with sulfuric acid; drying columns 5 and 6, filled with granular sodium hydroxide and magnesium perchlorate; porcelain tube 7 with a length of 500 mm and an inner diameter of 20−25 mm; tube furnace 8 stamps SUOL — 0.25.1/12-Ml; asbestos tube (9), saturated with lead monoxide, heated to a temperature of 800 °C; copper tubes 10 heated to a temperature of 110−120 °C; an l-shaped pipe 11; the absorption flasks 12 with magnesium perchlorate (angerona). L-shaped pipeline made of austenitic stainless steel and consists of two symmetrical separable parts, the total length of the pipeline is 750 mm. the Spiral heater is placed around and along the curved profile of the pipeline copper pipe while also isolating the heater turns of asbestos cord CHAON-3 impregnated with liquid glass. A tube with a heater braid tape made of PTFE and placed in the lower part of the housing pipeline, pre-lined with kaolin wool, top up with the heater also cover the kaolin wool and covers the upper part of the housing pipeline. Both parts of the case fasten with screws through the holes in the ears welded to the upper and lower parts of the pipeline.
Damn.1
Permitted heaters and absorption flasks other structures providing the required accuracy of the analysis.
The hook with which the boat was placed in a tube and extracted from it, is made of heat-resistant wire with a diameter of 3−5 mm and a length of 400−600 mm.
To install the tube in a porcelain tube using a special pusher with the catch.
Laboratory scales for General purpose according to GOST 24104*, not below 2nd class with the largest weighing limit of 200 g or other scales that meets the specified requirements for their metrological characteristics.
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* On the territory of the Russian Federation GOST 24104−2001, here and hereafter. — Note the manufacturer’s database.
To determine the mass fraction from 0.01 to 0.03% use laboratory scales for General purpose according to GOST 24104 is not below 1st class of accuracy.
Sulfuric acid according to GOST 4204.
Sodium hydroxide according to GOST 4328.
Of magnesium perchlorate on the other 6−09−3880.
Kaolin wool or asbestos fiber on the other 6−09−4010.
Lead monoxide (II) on the other 6−09−5382.
3. PREPARATION FOR ASSAY
Pour in the wash flask 4 125 cmof sulfuric acid. Drying columns 5 and 6, and the absorption flask 12 is prepared to work in accordance with the devil.2. The mass absorption flasks prepared in the form of (70±2) g. of magnesium Perchlorate should not asiatica tightly. Absorption flask with a diameter of 30 mm in the lower part 5−6 holes with a diameter of (1±0,2) mm Height of the absorption bulb 105 mm.
1 — glass wool; 2 — absorber; 3 — glass wool
Damn.2
In calcined along the entire length of the porcelain tube is placed a tube, impregnated with lead monoxide. The tube 9 from long staple asbestos or kaolin wool, pre-calcined at 400 °C for 30 min, prepared as follows: a steel brush pour a uniform layer of fibrous asbestos or kaolin wool and evenly cover the asbestos co-lead. By rubbing two steel brushes provide uniform distribution of monoxide lead asbestos. The excess of lead monoxide shake sieve. For impregnation of 100 g of asbestos requires about 100 g of monoxide of lead. 4,5−5,0 g impregnated asbestos (kaolin wool) is sufficient for the formation of the tube. Both sides of the tube are placed glass wool 10 mm on each side (Fig.3).
Damn.3
The constancy of oxygen consumption is determined by the flowmeter 2, which is installed in front of the safety bulb. The flow of oxygen through the system occurs at a rate of 175−225 cm/min.
Before starting, heat the oven to a temperature of 1000 °C and check the installation for leaks. For this connect instead of the absorption of the bulb (12) glass tube, the end of which dipped into a Cup of water and interrupt the flow of oxygen, holding the hose in front of the safety bulb. If the water in the glass tube rises, the system is sealed.
The ends of helical heater located around and along the curved profile of the pipe 11 of the copper tube 10 is connected to latro RNO-250−2 and set the voltage to the outlet temperature of the copper tube was 110−120 °C.
Porcelain boats N 2 according to GOST 9147 or quartz boat (length of 100−120 mm, width 15−20 mm, height 10 mm) was calcined in flowing oxygen at a temperature of 1000 °C before operation.
Before starting, set the average value of the blank experience. After the furnace temperature reaches 1000 °C, pass oxygen consumption 175−225 cm/min, weighing of the absorption flask 12 every 5−7 min. Installation ready to use when the difference in weight between each weighing not more than 0.2−0.4 mg. the Value of the idle experience more than 0.4 mg demonstrates the need for prevention of the installation. To do this, you must replace the reagents used for the dehydration of oxygen (sulfuric acid, sodium hydroxide and magnesium perchlorate) and to clean from contamination all parts of the installation.
Tube 9 provides a delay of fluoride to a large number of tests. Control over the operation of the tube is carried out by changing the color of perchlorate of magnesium in the absorption flask (12), caused by penetration of fluoride.
4. ANALYSIS
Weighed samples of ground mounted depending on the mass fraction of moisture on the table.1, placed in a porcelain or quartz boat.
Table 1
| Mass fraction of moisture, % |
The weight of the portion of flux, g |
| From 0,01 to 0,03 incl. |
7−10 |
| SV. Of 0.03 «to 0.07 « |
4−7 |
| «To 0.07» to 0.2 « |
2−4 |
| «0,2» 1,0 « |
0,5−2,0 |
A boat with a hook is introduced into the most heated portion of the porcelain tube (7) and tightly closed the tube with a rubber stopper through which passed a tube to supply oxygen. The moisture extracted from the sample is distilled in an absorption flask (12), while volatile side-products and fluoride are absorbed by the lead monoxide at the exit of the tube. The sample left in the furnace until, while in the upper part of the glass tube and absorption of the bulb (12) there will be condensation (no more than 5−7 minutes). Then seal the absorption flask 12, closing the top opening of the tube, the lower opening for exit of the oxygen tight rubber ring and weighed. Remove analyzed sample from the oven, connect the absorption flask 12 to install and start analyzing the next sample.
5. PROCESSING OF THE RESULTS
5.1. Mass fraction of moisture () in percent is calculated by the formula
where is the mass absorption flasks after analysis, g;
— the mass of the same flask prior to analysis, g;
— the weight of the portion of the flux to be analyzed,
5.2. Allowable absolute differences of the results of three parallel measurements at a confidence probability of 0.95 does not exceed the values given in table.2.
Table 2
| Mass fraction of moisture, % | Allowable absolute differences, % |
| From 0.01 to 0.02 incl. | 0,004 |
| SV. 0,02 «0,05 « | 0,008 |
| «0,05» 0,10 « | 0,01 |
| «To 0.10» to 0.50 « | 0,05 |
| «0,50» 1,00 « | 0,10 |
