Dichloromethane for industrial use (3)

4.

Take 100mL laboratory sample, weigh it to the nearest 0.

4.

The mass fraction of acid w ₁ (calculated as HC1), the value is expressed in %, calculated according to formula (1):

Where:

V—The value of the volume of the standard titration solution (4.

c— The exact value of the concentration of the sodium hydroxide standard titration solution, the unit is moles per liter (moI/L);

m—The value of the mass of the sample, in grams (g);

M— The value of the molar mass of hydrogen chloride , in grams per mole (g/mol) (M=36.

Take the arithmetic average of the two parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.

4.

Carry out according to the method specified in GB/T3143-1982

4.

Carry out according to the method specified in GB/T6324.

Take the arithmetic mean of the two parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.

5 Inspection rules

5.

5.

5.

a) Update key production processes;

b) The main raw materials have changed:

c) Stop production and resume production;

d) There is a big difference between the factory inspection results and the last type inspection;

e) Contract stipulations

5.
2 Industrial methylene chloride is a batch of homogeneous products of the same quality
.
One batch of barreled products shall be no more than 100t, or the volume of one storage tank or one tank shall be one batch
.

5.
3 Sampling of dichloromethane for industrial use shall be carried out in accordance with 7.
1 of GB/T6680-2003
.
The number of sampling units for barreled products shall be carried out in accordance with the provisions of GB/T6678-2003: the total amount of sampling shall meet the needs of inspection
.

5.
4 Dichloromethane for industrial use should be inspected by the quality inspection department of the manufacturer
.
Each batch of products should be accompanied by a quality certificate, which includes: product name, product grade, manufacturer name, factory address, batch number or production date and the standard number
.

5.
5 The inspection result is judged according to the rounding value comparison method in GB/T1250.
If an indicator of the inspection result does not meet the requirements of this standard, the barreled product shall be sampled from twice the number of packaging units for inspection.
Packed products and tanked products should be re-sampled for inspection
.
Even if only one index does not meet the requirements of this standard as a result of the re-inspection, the whole batch of products is unqualified
.

6 Marking, packaging, transportation and storage

6.
1 Industrial methylene chloride packaging containers should have firm and clear signs, including: product name, trademark, manufacturer name, factory address, net content, batch number, product grade, number of this standard, and “drug ”Mark, the “fear of the sun” and “fear of rain” signs specified in GB/T191-2000
.

6.
2 Dichloromethane for industrial use should be airtightly packed in dry and clean galvanized iron drums, protective-coated iron drums or tanks
.
Packed in iron drums, the net weight per drum is (200±0.
5)kg, (250±0.
5)kg, or according to user requirements
.

6.
3 The volume of galvanized iron drums, protective coating iron drums or tanks should be based on the total volume of the iron drums or tanks and the allowable temperature and other factors on the transportation of liquid methyl chloride products.
Zhang took it into consideration
.

6.
4 Dichloromethane products for industrial use should be stored in a cool, ventilated and dry place, not close to heat sources, and avoid exposure to the sun and rain
.

6.
5 Industrial methylene chloride products should not be impacted during transportation, loading and unloading, and should be handled with care to avoid damage to the packaging container and product leakage
.

6.
6 The stabilizer of industrial monochloromethane is methanol or pentene
.

6.
7 The shelf life of industrial methylene chloride after adding stabilizers is 6 months from the date of production
.

7 Security

Industrial methylene chloride is combustible when exposed to high heat from an open flame
.
Thermal decomposition can produce highly toxic phosgene
.
In case of high heat, the pressure in the container will increase, which may cause cracking and explosion
.

When contacting or using dichloromethane , you should wear necessary protective equipment.
When the skin contacts, use soapy water and clean water to thoroughly rinse the skin for at least 15 minutes.
When the eyes contact, rinse with running water or normal saline, and seek medical attention
.