GOST 25001-81
GOST 25001−81 Billets for rolling sheet heat exchangers-welded aluminum. Specifications (with Amendments No. 1, 2)
GOST 25001−81
Group B53
STATE STANDARD OF THE USSR
BLANKS FOR HEAT EXCHANGERS SHEET ROLLING-WELDED ALUMINUM
Specifications
Rolled-welded aluminium sheet billets for heat-exchangers. Specifications*______________
* The name of the standard. Changed the wording, Rev. N 2.
OKP 51 5222
Date of introduction 1983−01−01
Resolution of the USSR State Committee for standards, dated November 20, 1981 N 5050 validity period is set with
________________
* Expiration removed by the resolution of Gosstandart of the USSR from
MADE: the Change in N 1, approved and put into effect with
Change N 1, 2 made by the manufacturer of the database in the text IUS N 4, 1984, ICS # 11, 1987
This standard applies to sheet rolling-welded aluminum billet with two-sided blowing of the channels intended for the manufacture of heat exchangers and evaporators used in domestic refrigerators and freezers.
(Changed edition, Rev. N 2).
1. ASSORTMENT
1.1. Sheet rolling-welded blank made according to the drawings agreed between manufacturer and user.
The drawings indicate:
dimensions of workpieces (width and length) and maximum deviations;
length, width, outer height channels and maximum deviations;
the skewed pattern in the direction of rolling;
the place and size of the rolling input and output channels;
additional requirements.
1.1.1. The total length of channels located across the direction of rolling shall not exceed 25% of the total length of the channels.
1.1.2. The transition from transverse to longitudinal channel on the inner radius should be at least 3 mm.
1.1.3. The channel under the capillary tube must be located along the direction of the sheeting in the area of input-output channels.
At the request of the individual consumer sizes of workpieces Kamensk-Uralsky metallurgical plant manufactures a specified location of the channel across the direction of rolling.
1.1.4. Deviation of the longitudinal channels from straightness per meter length of the pattern should not be more than 5 mm.
1.2. Minimum distance between channels must be at least 10 mm.
1.3. Maximum deviations along the length of the pattern must be ±2% from nominal values.
Example of designation of sheet rolling-welded blanks intended for the manufacture of heat exchanger evaporator (TI) according to the drawing (XXX) aluminium brand AD with a width of 320 mm and a length of 1034 mm:
TI XXX HELL 320х1034 GOST 25001−81
Section 1. (Changed edition, Rev. N 2).
2. TECHNICAL REQUIREMENTS
2.1. Sheet rolling-welded blanks manufactured in accordance with the requirements of this standard technological instruction, duly approved.
2.1.1. Sheet rolling-welded blanks are made by rolling the cards out of aluminum grades A7, A6, A5 and A0 with the chemical composition according to GOST 11069−74 and aluminum brands AD0, AD1, HELL with the chemical composition according to GOST 4784−74* with an admissible mass fraction of iron to 0.5%.
________________
* On the territory of the Russian Federation the document is not valid. Valid GOST 4784−97. — Note the manufacturer’s database.
Cards are cut from hardened sheets of 3.0 mm thickness high precision and high surface finish according to GOST 21631−76.
2.2. Sheet rolling-manufacture of welded in the annealed condition.
2.1, 2.1.1, 2.2. (Changed edition, Rev. N 2).
2.3. (Deleted, Rev. N 2).
2.4. The surface of the workpiece sheet rolling-welded must be free of delamination, captive, tears, stains, corrosion of origin, inclusions and also spots and stripes from the burnt grease, if they are not removed in the control etching in a solution with a mass fraction of NaOH 8−10% at 50 °C for 2−3 min with subsequent bleaching in a solution with a mass fraction of HNO30%.
On the surface of the channels of the sheet rolling-bubbles-welded and socket from chipping sunsets are not allowed.
2.5. On the surface of the blanks of sheet rolling-welded are allowed:
1) metal fine sunsets with a total area of not more than 40 mm;
2) the Jack from chipping the sunsets, with a depth of not more than 0.06 mm. On each side of the sheet rolling-welded no more than 10 nests located in areas free from channels, at a distance of not less than 2 mm from the edge of the channel;
3) bubbles with a total area of not more than 20 mmwith the size of each bubble is not more than 10 mm
located in free space channels, at a distance of not less than 2 mm from the edge of the channel;
4) individual and group scratches with a depth of not more than 0.05 mm. On each side of the sheet rolling-welded no more than 5 scratches. Scratches in group location should not be more than 3 PCs, all of which are square 200x200 mm;
5) prints in the form of small dents with a depth of not more than 0.05 mm. On each side of the sheet rolling-welded no more than 5 prints;
6) prints from the rolls in the form of light and dark bands along the rolling;
7) attrition;
8) color of tint;
9) on each side of the sheet rolling-welded after chemical and mechanical treatment allowed in the field-free channels, at a distance of not less than 2 mm from the edge of the channel, hidden defects of metallurgical origin in the form of single inclusions with an area of not more than 1.5 mmand a depth not exceeding the thickness tolerances of the workpiece.
2.4, 2.5. (Changed edition, Rev. N 2).
2.6. Local widening of channels should not be more than one third of the width of the channel at a length of 15 mm for evaporators and 40 mm for capacitors. The total number of local caps allowed no more than two on each workpiece.
2.7. Inside the channels allowed dry residue not more than 30 mg per piece.
2.8. Inside the channels is not allowed the presence of moisture in the free state when cavalcando input and output channels.
2.9. The magnitude of the fluctuations in the volume of the channels from the value of the nominal volume of the feature channels up to 150 cm, inclusive, should not exceed ±12%.
The magnitude of the fluctuations in the volume of the channels from the value of the nominal volume of the feature channels over 150 cmis set in the drawing.
2.10. Channels of blanks of sheet rolling-welded shall be sealed and shall withstand a pressure not less than the 1.57 MPa (16 kgf/cm).
2.7−2.10. (Changed edition, Rev. N 2).
2.11. (Deleted, Rev. N 2).
3. ACCEPTANCE RULES
3.1. Sheet rolling-welded take parties.
The party should consist of blanks of the same size and decorated by one document on quality. The party should consist of blanks, the difference of fluctuations of channels which should not be more than 25% of the smaller value of the volume.
The document about quality should contain:
trademark or a trademark and the name of the manufacturer;
product name and size;
batch number;
the number of workpieces;
mark in TCI;
the date of shipment;
the designation of this standard.
3.2. To determine the chemical composition selected two blanks. Allowed the manufacturer to determine the chemical composition of the workpiece in accordance with the document on the quality of the manufacturer of the ingots or sheets.
3.3. The quality control of workpieces, the manufacturer checks: dimensions of workpieces, the length of the pattern and distortion on each workpiece; the height of the channels at each of the workpiece or the amount of channels on the three blanks from the party; the quality of the surface on each workpiece, the depth of the defects by 2% from the party, but not less than 20 PCs.
3.4. When the input quality control of blanks the consumer checks: the surface quality, the geometric dimensions and pattern, the presence of solids, the presence of moisture in the free state, the magnitude of the fluctuations in the volume of channels, the tightness.
The volume control is set by the user in accordance with GOST 24297−87.
3.4.1. Quality control of the surface of each blank to identify hidden defects, the consumer holds after mechanical and chemical treatment.
Number of workpieces with hidden defects
3.5. If unsatisfactory test results on them, repeat tests are carried out at twice the sample taken from the same batch. The results of repeated tests apply to the entire party.
Section 3. (Changed edition, Rev. N 2).
4. TEST METHODS
4.1. Analysis of chemical composition of aluminum is carried out according to GOST 25086−82*, GOST 12697.1−77-GOST 12697.12−77 or spectral method by GOST 3221−85.
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* Probably, the error of the original. Should read GOST 25086−81*. — Note the manufacturer’s database.
4.2. Dimensions of blanks of sheet rolling-welded is carried out using a measuring instrument to ensure the necessary measurement accuracy. The width and length of the workpiece, as well as the length and width of the drawing channel measure measuring metal ruler according to GOST 8026−75* or template.
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* On the territory of the Russian Federation the document is not valid. Standards 8026−92. — Note the manufacturer’s database.
4.1, 4.2. (Changed edition, Rev. N 2).
4.3. Tensile tests carried out according to GOST 1497−73*.
________________
* On the territory of the Russian Federation the document is not valid. Valid GOST 1497−84. — Note the manufacturer’s database.
4.4. Inspection of the surface of the workpiece is carried out without the use of magnifying devices.
The depth of defects measured by profilometer according to GOST 19300−86 or depth indicator (special) according to normative-technical documentation.
Checking the quality of the surface according to claim 2.5.9 is carried out after chemical treatment according to the method described in Annex 1.
4.5. Check the availability of moisture in the free state, conduct indicator — permanganate of potassium to redness on the flare or cut the input and output channels.
Check the availability of dry residue is carried out according to the method described in Annex 3.
4.4, 4.5. (Changed edition, Rev. N 2).
4.6. Control of the magnitude of fluctuations in the volume of the channels is carried out according to the method described in mandatory Appendix 4.
The leakage detection is carried out according to technical documentation approved in the established order.
(Changed edition, Rev. N 1).
5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE
5.1. On each blank sheet rolling-welded in place as indicated on the drawing shall be stamped with a metal stamp or suffered in other ways the lot number and the stamp of the technical control Department of the manufacturer.
At the request of the consumer on the blank stamp is not applied.
5.2. Temporary corrosion protection, packaging, transportation and storage — the graveyard 9.011−79.
Transport marking of packages according to GOST 14192−77 with application of manipulation signs «Caution fragile», «Afraid of dampness," «Top, do not turn over» and with an additional label: product name and size, grade of aluminum, and batch number.
At the customer’s request procurement of heat exchangers are subjected to conservation in accordance with the requirements of GOST 9.011−79.
5.1, 5.2. (Changed edition, Rev. N 2).
ANNEX 1 (mandatory). A METHOD OF CHEMICAL MACHINING OF HEAT EXCHANGERS
ANNEX 1
Mandatory*
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* Changed the wording, Rev. N 2.
The method is applied in the quality control of the work piece surface heat exchanger and comprises the sequence: etching, rinsing, bleaching, rinsing and drying.
1. Reagents
The caustic soda technical GOST 2263−79, the solution is 80−100 g/m.
Concentrated nitric acid GOST 4461−77, a solution of 200 g/m.
2. Testing
Etching of the surface is carried out in a solution of sodium hydroxide (NaOH) at a temperature of 60−70 °C for 2−3 min, then rinsed in warm running water at a temperature of 40−60 °C and then in cold running water at room temperature. Washing is carried out after bleaching the surface in a solution of nitric acid (HNO) at room temperature for 1−10 min until complete clarification. Washed in cold running water at room temperature and dried with heated air.
APPENDIX 2. (Deleted, Rev. N 2).
APPENDIX 3 (obligatory). CHECKING METHOD OF RESIDUAL CONTAMINATION
APPENDIX 3
Mandatory*
____________________________
* Changed the wording, Rev. N 2.
Checking method of residual contamination based on washing with solvent (Trichlorofluoromethane, trichloroethylene, or freon 113) of the controlled element followed by filtration of the solution and extraction of dry sediment.
1. Equipment and reagents
Trichloroethylene according to GOST 9976−83.
Trichlorofluoromethane.
Freon 113 according to GOST 23844−79.
Apparatus for the control and its mounting shown in Fig.
(Changed edition, Rev. N 2).
2. Testing
To connect the elements of the installation with clean, dry medical rubber pipe 1(see drawing). Start the vacuum pump 5 and the flush controlled element 2 pure solvent from vessel 3. Products flush go to an empty clean vessel 4. To intensify the washing process recommended from time to time to remove the tube 1 from the solvent.
If the solvent after passing through the controlled element remains clean, the flushing need to be completed. Thereafter, the tube 1 is removed from solvent and off the vacuum pump. The solution from the vessel 4 to be filtered through pre-dried at a temperature of 50−60 °C to constant mass filter with an accuracy of 0.1 mg. to Wash out the vessel with clean solvent and the solution filtered through the same filter. Put the spent filter in a drying Cabinet with a temperature of 50−60 °C and to carry out the evaporation of the solvent to constant weight filter. Determination of the mass of the filter before and after the tests are performed in the same conditions.
The increase in weight of the filter compared to the original, was adopted for the value of the residual contamination of the controlled element of the unit.
ANNEX 4 (required). A method of measuring the internal volume of the channel
ANNEX 4
Mandatory
The method is designed to control the magnitude of the fluctuations in the volume of the heat exchanger channels and based on the measurement of excess pressure in the channels when filling them with the measured amount of air.
1. The essence of the method
A method of measuring the internal volume of the channels is based on the law of Boyle under which the product of the volume of the gas at its pressure in an isothermal process remains constant.
2. Equipment
A working cylinder having an internal volume of from 300 to (500±5) cm.
Capacity with a calibrated internal volume: 100, 150, 175, 200, 225, 250, 300, 400, 450, 500 cm.
The exemplary pressure gauge spring-MO-250−6x0,25 according to GOST 6521−72.
3. Testing
Before measuring the internal volume of the channels of the test heat exchangers is carried out the calibration of the working cylinder (1) for a given ambient temperature. For this container (5) with a calibrated internal volume ,
,
connect alternately with the working cylinder via a pressure gauge (3) and move the piston (2) in the rightmost position.
Establish the dependence of graded volumes of the pressure for a specific temperature of the environment in the form of a graph or table.
1 — cylinder; 2 — piston; 3 — manometer; 4 — connecting pipe; 5 — capacity with a calibrated internal volume
Control the internal volume of the heat exchanger channels is carried out by supplying air from the working cylinder into the channels of the heat exchanger. The pressure on the pressure gauge is compared with the data table or graph and determine the internal volume of the channels, which is compared with nominal value. Measurement error the internal volume of the channels should not exceed 1% and consist of sum of the error of a measuring instrument and temperature fluctuations of the environment.
ANNEX 4. (Added, Rev. N 1).
The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: Publishing house of standards, 1982
Revision of the document including
changes and additions
prepared by JSC «Code»
