r'~I

i .-

CENTRAL MARKS DEPARTMENT-III.

Our Ref: CMD-IiI/16:122~5 (Part 17)/slr 11 042012

Subject: Amendment No.1, April 2012 to IS 12235 (Part 17 : 2004. Thermoplastics Pipes and Fitting~ - Method of Test

Part 17 Determination of Ash Content and SulphatedAsh Content (First Revision) .

Amendment No.1, April 2012 to IS 12235 (Part 17) : 2004 Thermoplastics Pipesand Fittings - Method of Test, Part 17 Determination of Ash content andsulphated ash content (First Revision) has been published (copy enclosed).The IS being test methods, there is no Scheme of Testing and Inspection (STI).This is circulated fo"rinformation.

~_.,~y. '~td\V-

(R Bhanu Prakash)Sc-E/Director (CMD-III)

Ene\.: As stated

Sc-F & H

Circulated to ROs/BOs/IOs/BIS Labs

Copy to :

Sc-F & Head (CMD-I)

Sc-G & Head (CED) - For Gazette Notification

Head (ITSD) - for posting on BIS (Intranet)

~

1,:~.,

I.

I

r .

'10

AMENDMENTNO." APRIL 2012TO

IS 12235(pART 17) : 2004THERMOPLASTICSPIPES ANDFITTINGS-METHODSOF TEST

PART 17 DETERMINATION OF ASH CONTENTAND SULPHATED ASH CONTENT

(First Revision)

(Pages 47 and 48) - Substitutethe following for the existing matter:1 SCOPE

This standard (Part 17) specifies methods of determination of the ash content of pipes and fittings made ofunplasticized polyvinyl chloride (pVC-U). For ash, Method A is used. For sulphated ash, Methods B and C areapplicable when lead-containing compounds are present. These methods can also be used for PVC resins andcompounds. .

Note - Polyvinyl chloride evolves hydrogen chloride on thermal decomposition, and precautions should be taken to avoidinhalationof fumes.

2 PRINCIPLE

2.1 Method A (Direct Calcination)

The organic matter in a test portion is burnt off and the residue is heated at 950°C until constant mass is reached.

2.2 Method B (Calcination, With Sulfuric Acid Treatment After Combustion)

The organic matter in a test portion is burnt off, the residue is converted into sulfates using concentrated sulfuricacid and finally the residue is heated at 950°C until constant mass is reached.

2.3 Method C (Calcination, With Sulfuric Acid Treatment Before Combustion)

The organic matter in a test portion is burnt off after adding concentrated sulfuric acid and the residue is heatedat 950°C until constant mass is reached. This method is recommended over Method B because of the .better

reproducibility of the results.

Method B or Method C should be used if lead-containing compounds are present.

3 REAGENTS (FOR METHODS BAND CONLY)

3.1 Sulfuricacid, density 1.84gtml, analytical grade.

3.2 Acetic acid, 100percent, analytical grade.

WARNING- Care should be taken inbandling sulfuric acid and acetic acid.

4 APPARATUS

4.1 Silica or Platinum Crucible, with lid inert to the material tested. The size shall be sufficient so that thecrucible is not more than half by the test portion sample.

4.2 Gas Burner or Other Appropriate Heat Source

4.3 Muffle Furnace or Microwave Furnace, capable of being maintained at 950°C :f:50°C as appropriate.

4.4 Analytical Balance, accurate to 0.1 mg.

Price Group 2

1

.,-1)

Amend No.1 to IS 12235 (Part 17) : 2004~.

4.5 Pipettes, of suitable capacity (f()rMethods B and Conly).

WARNING- In 6.3.4 and 6.4.3, it is required to use a pipette for the addition of concentrated sulfuric acid. The acid must beintroduced into the pipette using a suitable device (for example a rubber-bulb pipette filler) and must never be sucked up bymouth.

4.6 Desiccator, containing an effective drying agent that does not react chemically with the ash components.

NOTE - In some cases, the affinity of the ash for water may be greater than that of the drying agents commonly used.

5 SAFETY PRECAUTIONS

5.1 Always wear safety glasses when working in the laboratory.

5.2 Exercise all normal safety precautions when working with an open flame or at high temperatures. Useinsulated glovesand long crucible tongs when putting samples in the muffle furnace or taking them out of it.

5.3 Carry out the heating of the sample in a fume cupboard, and for calcinations use an appropriately ventedmuffle furnace.

5.4 Read carefully and follow strictly the instruction in the warnings at beginning of the text and in clause 3 andsubclauses 4.5 and 6.4.3.

6 PROCEDURE

6.1 Test Piece

The recommended test piece size is given in Table 1.

Table 1 Mass of Test Portion

Sample Test Pieceg

525

6.2 Method A (Determination. of Unsulfated Ash)

6.2.1 Heat the clean crucible and lid in the muffle furnace at 950°C :I:50°C for 10 min and cool in thedesiccatorto room temperature. Weigh the crucible with lid to the nearest 0,1 mg.

6.2.2 Introduce into the crucible a suitable quantity of sample (see Tablel) (finished product samples shouldpreferably be cut into small pieces). Weigh to crucible with lid and test portion to the nearest 0.1 mg andcalculatethe mass of the test portion (mo).

6.2.3 Heat the crucible directly on the heating device so that the test portion burns slowly and loss of ash isavoided. Continuethis operation until no more smoke is evolved.

In the event of violent burning, the test portion may be added in successive portions.

6.2.4 Partially close the crucible with the lid so that the volatile matter evolved does not carry away particles ofash. Place the crucible at the entrance of the muffle furnace maintained.at 950°C:I: 50°C (the temperature in theentrance zone is about 300°C to 400°C), then advance the crucible slowly into the furnace. Calcinate for 30 minat 950°C :I:50°C.

It is recommendedthat the design of the lid be such that, when placed on the crucible, the lid fits well but doesnot closethe crucible completely.

2

~

-~---~ ~ ~-~

"

... Amend No.1 to IS 12235 (Part 17) : 20046.2.5 Remove the crucible with lid from the furnace, place' it in the desiccators, allow to cool to roomtemperatureand weigh to the nearest 0.1 mg (ml)'

6.2.6 Calcinate again, under the same conditions, until constant mass is reached; that is until the results of twoconsecutive weighings do not differ by more than 0.5 mg. The total duration of heating in the furnace shanhowever not exceed 3 h. If constant mass is not attained after this time, the mass after 3 h shall be used forcalculatingthe test results.

6.3 Method B (Determination of Sulfated Ash)

6.3.1 Proceed as detailed in 6.2.1.

6.3.2 Proceed as detailed in 6.2.2.

6.3.3 Proceed as detailed in 6.2.3.

6.3.4 After allowing the crucible and contents to cool, add concentrated sulfuric acid dropwise by means of apipette of suitable capacity until the residue is soaked completely. Heat carefully on a suitable heating deviceuntil the evolution of smoke ceases, taking care to avoid spattering of the contents of the crucible.-

6.3.5 If, after allowing the crucible to cool, carbon is still evident, add 1 to 5 drops of sulfuric acid and reheatuntUevolution of white fumes has ceased.

6.3.6 Place the crucible at the entrance of the muffle furnace maintained at 950°C % 50°C and proceed asdetailed in 6.2.4, 6.2.5 and 6.2.6. The residue after calcinationsshall be grey or white, but not black.

6.4 Method C (Determination of Sulfated Ash)

6.4.1 Heat the clean crucible and lid in the muffle furnace at 950°C % 50°C for 10 min and cool in thedesiccator to room temperature. Weigh the crucible with lid to the nearest 0.1 mg.

6.4.2 Introduce into the crucible a suitable quantity of sample (see Tablet) (finished product samples shouldpreferably be cut into small pieces). Weigh the crucible with lid and test portion to the nearest 0.1 mg andcalculatethemassofthetestportion(mo). -

6.4.3 Using a pipette, add drop by drop the minimum possible quantity of concentrated sulfuric acid necessaryto wet the test portion evenly. Close the crucible with the cover and heat on the heating device. Repeat thisoperationuntil cracking and carbonization are over.

In cases where the sulfuric acid tends to creep over the edge of the crucible or where, despite precautions, someof the test portion tends to be lost from the crucible by violent reaction, the concentrated sulfuric acid may bereplaced by a mixture of concentrated acetic acid and concentrated sulfuric acid. The use of this mixed acid shallbe agreed between the interested parties, however, and reference made to it in the test report.

WARNING- Carbonization is required before ignition since explosive combustion takes place if the crucible is put in thefurnaceimmediatelyafteradditionof thesulfuricacid. /

Care should be taken in preparing and handling the mixture of concentrated acetic acid and concentrated sulfuricacid.

6.4.4 Partiallyclose the crucible with the lid so that the volatile matter evolved does not cany away particles ofash.Placethecrucibleat the entranceof themufflefurnacemaintainedat 950°C%50°C (thetemperatureintheentrance zone is about 300°C to 400°C), then advance the crucible slowly into the furnace. Calcinate for 30 minat 950°C %50°C.

It is recommendedthat the design of the lid be such that, when placed on the crucible, the lid fits well but doesnot close the crucible completely.

3

t;

Amend No.1 to IS 12235 (Part 17) : 2004 .-'

6.4.5 Remove the crucible with lid from the furnace, place it in the desiccators, allow to cool to roomtemperatureandweighto thenearest0.1mg(ml). '

6.4.6 Calcinate again, under the same conditions, until constant mass is reached; that is, until the results of twoconsecutive weighings do not differ by more than 0.5 mg. The total duration of heating in the furnace shall,however, not exceed 3 h. If constant mass is not attained after this time, the mass after 3 h shall be used forcalculating the test results.

7 NUMBER OF DETERMINATIONS

Carry out two determinations. Calculate the arithmetic mean of the results. If the individual test results differ bymore than 5 percent of their mean, repeat the procedure until two successive results do not differ from eachotherbymorethan5percentof theirmean. '

8 EXPRESSION OF RESULTS

The unsulfated ash content (Method A) or sulfated ash content (Methods B and C), expressed in grams'Per100g of sample, is given by the formula:

m. xlOO~

wheremois the mass of the test portion, in grams; andml is the mass of ash obtained, in grams.

9 TEST REPORT

The test report,shall contain the following particulars:

a) A reference to this standard;

b) Complete identification of the sample, including type, manufacturer's code number, source, trade nameetc;

c) Methodused, that is:

Method A - ashat950°C,Method B - ash at 950°C, and

Method C - ash at 950°C;

d) Mass of each of the two test portions used;e) Individual results of the two determinations and the mean ash content; and

t) If constantmass is not attained after 3 h, report that fact.

" (CED 50)Reprography Unit.IfIS, New Delhi, India

4

~

~