Reasoned document - Indian Railwayrdso.indianrailways.gov.in/works/uploads/File/reasoned doc for...

Reasoned document

1.0 Draft specification No.TI/SPC/OHE/INSCOM/1072 (…./2016)for “Technical

specification for silicone composite insulators for 25 kv a.c. 50 hz single phase overhead

traction equipment have been uploaded on RDSO website for comments from

manufacturers.

2.0 Comments received from manufacturers on clauses modified/newly added have been

tabulated below.

3.0 On Specification clauses where firms have not furnished any comments, it has been

considered as Nil comment.

Clause no Name of firm

Comment by firm RDSO’s remark

3.1.2

The core shall be sound and free of cracks,

impurities and voids that may adversely affect

the insulators void free and. It shall have high

resistance to acid corrosion.

DECCAN Nil No change. ABI No Comments/No

Suggestions.

GIL Draft Specification seems to be in line with the requirements of a good quality product. We have no suggestions.

BHEL found in order.

AESPL Nil.

Prithvi It is accepted and good for future prospects.

Raychem Nil.

3.2.2

The material shall conform to the tests

specified in this Specification. The material

preferably shall be such that it should not

attract Rats/Birds/Squirrels/Monkeys and

other rodents at storage location or on the

line. The thickness of Shed at edge should not

be less than 2.5mm to minimize the external

damage. The strength of shed to sheath

interface shall be greater than the tearing

strength of polymer. Manufacturer shall

indicate the solvent etc. to be used for

cleaning Silicone Rubber Sheds along with

method of cleaning.

DECCAN Nil. No change.

ABI No Comments/No Suggestions.



AESPL Nil.

Prithvi It is not required to be mention because the strength of shed to sheath is always greater than the tearing strength of the polymer.

Raychem Nil.

3.3.2

End fittings shall be free from cracks, seams,

shrinks air holes and rough edges .The surface

of metal parts shall be perfectly smooth with

the projecting points or irregularities which

may cause corona.





AESPL Nil.

Prithvi Nil.

Raychem Nil 3.3.3

The Metal Fittings shall be hot-dip galvanized in accordance with Specification No. ETI/OHE/13(4/84)-latest, after machining. The Galvanized surface shall be smooth, uniform adherent, reasonably bright continuous and free from imperfections such as flux, ash rust, stains, bulky white deposits and blisters. The mass of zinc coating on Threaded portion of the hook of Stay Arm Insulator shall not be applicable. The minimum weight of zinc coating shall be 1000

g/m2

(min) for all types of Metal Fitting and

750 g/m2(min) for Stay Arm Insulator Hook.

NOTE: The threads of the tapped holes in the

Metal Fittings of Stay Arm, Operating Rod &

Post Insulator shall be cut after galvanization

and protected against corrosion by application

of suitable grease. The threads of Hook for

Stay Arm Insulator shall be cut before

galvanization. All the tapped holes shall be

suitable for fixing galvanized Bolts and shall

conform to IS: 4218 (Part I to VI)-latest.





AESPL Nil.

Prithvi Nil.

Raychem

Nil.

3.4.1

Pultrusion process should preferably be

adopted to manufacture the FRP Rod/Core.

The temperature of Die and speed of

individual Fiber movement shall be so

controlled that, there are no cracks on the FRP

rod. The rod shall be resistant to hydrolysis.

Glass fibers and resin shall be optimized. The

core shall conform to the tests specified in this

Specification.

Cleaning of FRP rod should be done in such a

way so as to remove polar and non-polar





AESPL Nil.

Prithvi Nil.

Nil.

impurities stuck on the surface of rod.

Special care should be taken by manufacturer

while handling these rods so that no dust

deposition takes place on the surface of FRP

rod. Application of primer over FRP rod plays a

vital role in the quality of the final product.

The manufacturer should ensure that proper

heating cycle is followed after application of

primer, as per the instruction given by primer

manufacturer.

Raychem

3.4.3

Metal End Fittings shall be fitted on the Rod by

crimping process, prior to moulding of Sheds,

to ensure better sealing & avoiding water

ingress. They shall be connected to the rod by

means of a controlled Compression technique.

The manufacturer shall have in process

Acoustic emission arrangement or some other

arrangement to ensure that there is no

damage to the core (FRP) during crimping.

This verification shall be in-process and done

on each insulator. The strength of bond

between Metal Fitting & Sheath shall be more

than the tearing strength of the polymer

material. The gap between end fitting and

overlapping sleeve shall be sealed by a

suitable silicone compound. The sealing shall

stick to both overlapping sleeve and metal end

fitting. The sealing must be humidity proof

and durable with time.

In order to have adequate grippingbetween

FRP rod and metal fitting, the manufacturer

should properly define parameters for inner

surface roughness of metal fittings.

DECCAN Remove’ -The gap between and overlapping sleeve shall be seal by a suitable Silicone Compound. The sealing shall stick to both ovelaping sleeve and Metal end fitting. The sealing must be humidity proof and durable with time.” Reason- Not internationally accepted manufacturing practice and is not a proven technology either.

Following para of clause :3.4.3 shall be deleted, ‘’The gap between and overlapping sleeve shall be seal by a suitable Silicone Compound. The sealing shall stick to both ovelaping sleeve and Metal end fitting. The sealing must be humidity proof and durable with time.”




AESPL Since dimension of FRP rod, metal fitting & SML of insulator has already been defined in specification for which adequate pressure of crimping M/C will be optimized to achieve the specified SML without failure/crack of rod, which will remain set parameter of production. Hence, the use of another arrangement is not necessary as all parameters are pre-fixed.

As clarified above, as griping will be achieved by set parameter, hence surface roughness of metal fitting may not be required to define.

Prithvi All the crimped Insulators are load tested before mouling to check proper crimping and damage there of. So further acoustic emission arrangement (AEA) is a confirmatory one. It has no impact on further improvement in manufacturing process, hence it should not be considered and not required. Rest advised procedures are ok.

Raychem This should be removed

as all designs as per RDSO Specification are with crimping first and then moulding. This ensures direct moulding on end fitting and there is no requirement of special sealing.

3.4.5

The interface between the housing and the

core must be uniform and without voids. The

strength of the bond shall be greater than the

tearing strength of the polymer. The

manufacturer shall follow non- destructive

technique (N.D.T) to check the quality of

jointing of the housing interface with the core

(FRP). The technique to be followed with

detailed procedure and sampling shall be

included in QAP.

DECCAN Nil. NDT tests techniques e.g Ultrasonic/Radiography etc shall be added.




AESPL As this equipment may not be full proof to ensure the perfect bonding throughout length of insulator, hence this test set-up should not be mandatory as peel off test is already incorporated.

Prithvi Whenever peel off strength is checked then requirement of NDT

testing is meaningless and is not required. These types of test are required for 220 kV or above transmission Insulators. Introduction fo such type of odd non required test will help to short list the present vendors and will help to create monopolistic business for few vendors. We have already objected and described out comments in the joint meeting at RDSO held on 20.07.2016 for such type of odd implementation. Peel off test is also sufficient to check bonding the silicone Compound and FRP glass Rod.

Raychem Nil. 4.1.3.

In no case, Insulator Manufacturer shall

change the make, grade, type or composition

of the Rubber Compound/primer without

repeating the Type tests related to Electrical

and Material properties.





AESPL Nil.

Prithvi Nil.

Raychem Nil. 4.1.4

Type tests shall be repeated, whenever the

design or manufacturing process or the

Insulating material/Bonding material of the

Insulator is changed/modified or as per latest

policy guidelines of RDSO. or at the time of

renewal of Vendor approval/registration

although type wise vendor status i.e. Part-I

/Part-II shall remain the same. The Approval/

Renewal of approval shall be accorded by

Director General (TI), RDSO, Lucknow, for 2

to 3 years or as per latest policy of RDSO.





AESPL Nil.

Prithvi Nil.

Raychem Nil.

4.1.5

The following type tests shall be carried out on

the Insulators /test Specimens at the works of



the manufacturer or at any

Government/NABL/NABCB accredited

laboratory in the presence of the

representative of the Director General (TI),

RDSO, Lucknow, and in accordance with the

relevant procedures laid down in this

Specifications:



AESPL Nil.

Prithvi Nil.

Raychem Nil. 4.1.5 (Table-2)

7.4.4: Peel off Test : 03 Nos. on each type.

7.4.5: Non-destructive technique (N.D.T) Test: 03

Nos. on each type.

DECCAN Nil. Fives firms are agreeing ,hance no change.

ABI 7.4.4-We can

perform this test

during Type testing.

7.4.5- No

Comments/No

Suggestions. GIL Draft Specification

seems to be in line with the requirements of a good quality product. We have no suggestions.

BHEL found in order. AESPL Nil.

Prithvi 7.4.4-Nil. 7.4.5- Not required and irrelevant.

Raychem Nil.

4.1.5, Note

(i) Test at Sl. No. 8.1 & 8.2 shall be carried

out on samples as mentioned above or as

specified in their relevant standards

(whichever is higher shall be taken). These

tests need not be repeated, if the material of

the Sleeve/Housing is of same grade of the

same rubber manufacturer used for other

types of Insulator(s) offered for Prototype

tests.





AESPL Nil.

Prithvi Nil.

Raychem Nil.

4.1.5, Note

(ii)Test at Sl. No. 8.2 shall be carried out on

samples as mentioned above or as specified in

their relevant standards (whichever is higher

shall be taken). These tests need not be

repeated, if the material of Core(Glass Fiber)

are of the same batch used for other types of

Insulator(s) offered for Prototype tests.





AESPL Nil.

Prithvi Note-2 it is not required.

Raychem Nil.

4.1.5, Note

(iv)The Tests, mentioned at Sl. No. 13 above,

shall be carried out on any one type of

Insulator (preferably on 9-Tonne Insulators) in

case the design of Insulator (excluding End

Fittings) is same for all the types offered for

prototype testing. Also, the Power Arc test

shall be carried out on any one type of

Insulator, preferably on Sectioning Insulator

out of Post, Operating & Sectioning

Insulators. They shall be repeated with a time

gap of every 5 to 6 years or till in case there

is any change in design of the Insulators.

offered for prototype tests. whichever is

earlier.





AESPL Nil.

Prithvi Nil.

Raychem

Nil.

4.1.5, Note

(v)The Tests mentioned at Sl. No. 14 & 15

above, shall be conducted on any one type of

Insulator only. They shall be repeated with a

time gap of every 5 to 6 years oruntil in case

there is any change in design/material/grade

(Polymer compound) of the Insulators offered

for Prototype tests whichever is earlier.


ABI Nil.



AESPL Nil.

Prithvi Nil.

Raychem Nil.

4.1.5, Note

(vii)The test on interface & connections of

Metal Fittings shall be carried out on any one

type of Insulators (preferably on 9-Tonne

insulator) at the time of renewal of Vendor

approval/registration only (if offered at a

time), in case the design of Insulator

(excluding End Fittings) is same.





AESPL Nil.

Prithvi Nil.

Raychem Nil. 4.1.5, Note

(viii) In case of Insulators manufacturers

change the material of Metal Fitting

/manufacturer of Metal Fitting. The tests

mentioned at Sl. No. 1.0, 2.0 3.1, 3.3, 4.0,

5.0 & 6.0 above will be carried out.





AESPL Nil.

Prithvi Note-8

In case of change in supplier of metal fittings, if the metal fitting manufacturer is already approved by your other approved vendors and metals are already in use by your other approved vendors. In that case it should be allowed and no testing should be required except manufacturers tests certificate.

Raychem Nil.

4.3.3

The manufacturer shall follow non-destructive

technique (N.D.T) to check the quality of

jointing of the housing interface with the core

(FRP). This test shall be carried out on every

Insulator.

DECCAN Nil. NDT tests techniques e.g Ultrasonic/Radiography etc shall be added.




AESPL Nil.

Prithvi Absolutely irrelevant and non required comments have already been made earlier.

Raychem Nil.

4.4.3 (Table-3) SN-6 : Mechanical Performance Test And Peel off test- A-3.3 :A-7.4.4 SN- 9: N.D.T-3.4.5-3 Nos.

DECCAN Nil. Fives firms are agreeing , hance no change.

ABI Peel off test- we can perform these tests during Acceptance testing as per the sampling plan. N.D.T- No Comments/No Suggestions.



AESPL Nil.

Prithvi SN-6 –Nil SN-9

Not required and irrelevant.

Raychem Nil.

7.3

Each insulator should have laser marking on top

and bottom shed towards outer periphery in the

following format:-

Make-XXXX-MM-YYYY.

Where, XXXX indicate the serial number of insulator

manufactured in a particular month.

MM- month of Manufacture.

YYYY-Year of Manufacture

Manufacturer should ensure unique serial number

with traceability to determine the raw material batch

used. Record should be made available to RDSO/ Rites

during Inspection.

DECCAN Delete Cl-7.3 Reason-Bulk Laser Marking is not feasible under Indian factory environment and for aerodynamic inclined shed in both directions.

Laser marking/alternate permanent marking method shall be incorporated.

ABI Laser marking is not possible. we are following bar coding system to identify each insulator.



AESPL The marking on insulator in present specification is adequate to ensure the traceability of manufactured insulators such as month & year, logo of manufacture, trade mark which has already been incorporated in mould itself as well on metal fittings. Although, traceability of each insulators are being maintain batch-wise as per QAP but Sr. no. on insulator will not be practical to maintain during mass production. Hence, laser marking may not be suitable as insulator are being design for outdoor application.

Prithvi Although marking are already embossed on Insulators while moulding, hence further Laser marking is not

relevant.

Raychem In place of Laser we are proposing as below: 1)Unique serial No we propose on end fitting through prior printer which is more robust and long lasting than Laser. 2) Manufacturer name, month and year are mentioned as embossing in injection moulding on housing. This is permanent and more robust and long lasting than Laser marking. It will not deteriorate due pollution. 3)Laser printing shall get deteriorate and may not be visible due to pollution, flash over failures.

10.2: Minimum Mechanical Failing Load and Bending Moment and Torsion Moment (Table-5). Torsional moment for Post Insulator changed to 200 kgf-m from 550 kgf-m.





AESPL Nil.

Prithvi Nil.

Raychem Nil.

11.1

The manufacturer shall guarantee that there

shall not be any failure/ decapping/breaking of

insulators online under normal operating

conditions. In the event of any failure/

decapping/breaking of insulators during the

first five years from the month of

commissioning, manufacturer shall supply to

the consignee/railway spare insulator equal to

5 times the failed insulatorquantity.

DECCAN After Sale service: Delete In the event of failure/decapping /breaking of Insulators online under normal operating conditions during the first 5 year from the month of commissioning. Reason- reason for failure/decapping /breaking of Insulators online is not always attributable to manufacturing defect

This paragraph proposed to be deleted. Action shall be taken as per latest ISO guidelines.

failures can be due to severe power arc due to delay tripping physical damage during installation are in use etc. It will be practically very difficult to determine normal operating conditions.




AESPL Although,

manufacturing of

insulators follow the

approved

manufacturing

process, parameters,

prototype testing, raw

materials types,

source etc. by RDSO

& further acceptance

test by RITES before

supply & quality

check by consignee at

store before release

for installation, hence

possibility of rejection

are negligible.

Further, it may not be

possible for life-time

guarantee of products

as to human errors,

transportation,

storage,

environmental

condition, application.

It will not be justify

the warrantee for 5

years from date of

commissioning

whereas materials are

stored for long period

approx. 2-3 years

after supply & we

don’t know the

storage condition.

Hence, the present

warranty period i.e. 2

years is more than

appropriate.

However,

manufacture’s prime

responsibility to

ensure the best

quality of product &

ensure the after sales

service.

Prithvi Though it’s a commercial condition, it should be a part of Tender terms and even if it si considered in specification according to definition of gurantee, “the failure product has to be replaced with a new product but not with extra quantity as it define i.e five(5) times.

Raychem Nil.

12.0

This Specification supersedes the earlier

Specification No.

TI/SPC/OHE/INSCOM/1070 1071 issued

on 19.01.2007 April 2013.


ABI Nil.



AESPL Nil.

Prithvi Nil.

Raychem Nil. 13.0

New Clause added as per A & C No-01 of

RDSO Specification No

TI/SPC/OHE/INSCOM/1071 issued on

13.10.2016.

“All the provisions contained in RDSO’s ISO

procedures laid down in document No.- QO-D-

7.1-11 dated 19.07.2016 (Titled “ Vendor-

change in approved status”) and subsequent

versions/amendments thereof, shall be binding

and applicable on the successful

vendor//vendors in the contracts floated by

Railways to maintain quality of products

supplied to Railways”

NA NA Included.

A-3.5 TORSION TEST

This test shall be done only on the Post

Insulator. The Insulator shall be subjected to a

Torsional Load without causing any Bending

whatsoever. Depending upon the length of the


ABI Nil.

GIL Draft Specification seems to be in line with the requirements of a

lever arm used for imparting the torsion, the

load corresponding to the minimum Torsional

failing moment shall be calculated and 70% of

the value of Load so calculated shall be

gradually applied at the end of the lever arm

and maintained at that value for one minute.

The load shall then be raised at the same rate

till failure of crimping/fracture of FRP

Rod/Permanent deformation in FRP Rod shall

takes place. The Torsional moment shall be

calculated with the load at which the failure of

crimping/fracture of FRP Rod/Permanent

deformation in FRP Rod shall takes place by

multiplying the load and the lever arm length

and that failure shall occur at a torsional

moment shall not be less than the minimum

specified value in Table-5. It may be noted

that no twist shall be there till 70% of

specified torsional moment and a maximum

200

twist is permitted at torsional moment

specified in Table-5.The maximum twist shall

be measured at 385 kgfm&550 kgfm during

torsion test and shall be mentioned in the Test

Report.

good quality product. We have no suggestions.


AESPL Nil.

Prithvi Nil.

Raychem Nil.

A-7.4.2 STEEP FRONT IMPULSE VOLTAGE

TEST

The voltage shall be applied to the

original Metal Fittings of the Insulator as

the insulation length of the insulator is

smaller than 500 mm.

An impulse voltage with a steepness of at

least 1000 kV/µs shall be applied between

the Metal Fitting. Each Insulator is to be

stressed with 25 impulses of positive and

25 impulses of negative polarity. Each

impulse shall cause external flashover

between the electrodes & no puncture

shall occur. This test shall be carried at

CPRI, Bangalore/ERDA or any other

Government Laboratory having

NABL/NABCB accreditation.

DECCAN This test shall be carried out at CPRI, Bangalore/ERADA or any other laboratory having certified by NABL/NABCB. Reason-Instead of accreditation by NABL/NABCB, it should be certified by NABL/NABCB so as to conduct the test at manufacturer test set up.

Fives firms are agreeing ,hance no change.

ABI Nil.



AESPL Nil.

Prithvi Nil.

Raychem Nil.

A-7.4.4 PEEL OFF TEST

The bonding between FRP Rod and housing to

be verified through peel of test in each shift.

This test shall be carried out on assembled

insulator after injection moulding. Samples of

Silicone Composite Insulators as detailed in

Table 2 shall be taken from the insulators

subjected to Mechanical Failing Load Test.―U‖

shape cut on sheath portion shall be made so

that rubber can be pulled using plier from

bottom portion of

―U‖ shape cut. While pulling the rubber, it

should not be peel off from the FRP surface

instead it should break leaving residue on the

FRP surface. In case the rubber peels off

without leaving any residue on FRP Rod, the

sample should be treated as failed. Peeled

samples should be stored by manufacturer for

02 years for record purpose.

DECCAN This test to be carried as an acceptance test instead of each shift. Delete- samples should be stored by manufacturer for two year record purpose. Reason- peel test is a destructive test and carrying out the test for every shift is not feasible. Similarly storing large no of samples for two year is also not feasible.

(i)The meaning of shift is defined as the duration starting from the starting of injection moulding process of Railway Insulator till the stopping of the moulding process.

(ii) Following

shall be

deleted

”Peeled

samples

should be

stored by

manufacturer

for 02 years

for record

purpose.”

ABI Verification of Peel off test in each shift is not possible. We can do Peel off test on the samples of silicone Composite Insulators as detailed in Table-2. The sample will be taken from the Insulators subjected to mechanical failing load test as suggested.



AESPL Although suggested test is good to ensure the quality of bonding but test on insulator per shift will not be practical as test are destructive &create huge wastage(which will be 60 nos. insulator per month) to maintain for two years. But this can be define to use during acceptance test by RITS.

Prithvi PEEL OFF TEST: Every time the production is done on batch basis therefore the sample from each batch

may be taken at random basis to conduct test and tested sample may be kept with proper identification mark as referral sample for evaluation in future if required.

Raychem Nil.

Other Points raised by firms. 8.0 PACKING

8.1

The Insulators shall be securely packed first

with thick Polythene Bag. It shall be kept

inside 7 Ply (140-120-120-120-120-120-140)

Cardboard Box having 75 mm thickness

Thermocol at both the ends of Box.

Appropriate hole to support the Metal Fitting

shall be made in the Thermocol.

8.2

Care shall be taken to ensure that Sheds of

the Insulators shall not touch each other and

the walls of the Box. It shall be ensured that

there is no damage to Sheds during loading

& transportation. Not more than four

Insulators shall be packed in a Box, so as to

facilitate manual loading and unloading. The

manufacturer shall provide instruction leaflet

regarding handling & storage of the

Insulators to individual consignees in English

and Hindi language along with thesupplies.

DECCAN Improvement in packing using Rodent repellents In packing boxes and Cling rapping the box. This will prevent Rodent entry.

This has been covered in clause 3.2.2 above.

Appendix-B (Page 35 & 36 and related curves). BHEL Corrections of test

voltages for

atmospheric

conditions in page 35

& 36 and related

curves are out dated.

methods given in IEC

60-1 (latest) can be

referred.

Not accepted , Corrections of

test voltages

for

atmospheric

conditions

mentioned in

Appendix B is

as per IS:

713

Additions:

DECCAN 1) 5000 Hrs multi stress test as per IEC-61109 of 1992 should included and should carried ones at the time of initial assessment and should be valid for that design.

Not accepted as this has been deleted in the latest version of IEC-61109-2008. As per latest IEC: 62217-2012

Any change in design only, the test should be repeated. 2) Present specified test on Housing material, core material and end fitting materials are adequate for the quality test. 3) Whenever there is any change of supplier, whose materials are meeting the RRDSO Specification, the same should be approved with materials tests only if they meet the all the specifications. Reason- Aging test is critical to ensure long term performance of the Insulator. This is a mandatory test by all Transmission Utilities in India.

(referred in IEC-61109) the 1000 hours Salt fog Tracking & Erosion Test is specified to consider as screening test intended to reject the material or design.

Test addition Table-3, clause 11.1 Dye Penetration Test- IEC 61109 Table-2, clause 8.2.2 Dye Penetration Test

A-8.2 (b)

Dye Penetration Test-IEC 62217 (Clause 9.4.1)

Raychem

Dye Penetration Test shall be conducted as per IEC-62217 cl-9.4.1.1 (using solution Astrazon in Methanol (IEC-62217, page-19).

Already defined in clause No. A-8.2 (b).

Value Additon Table-5: Minimum mechanical failing loads, bending and torsional moments.

MDCL (Maximum Design Cantilever Load) values and its verification shall be added in the RDSO Specification as per IEC-61952. MDCL value=1KN-m(50% of bending load), only for Bracket and Stay arm Insulators. As Bending load is critical these two Insulators all these series of test to be done with MDCL value. Table-5 to be updated with MDCL value.

Thermo-Mechanical test have been specified as per IEC-61109-2008 and parameters have been defined accordingly.

Type test addition A-5: Assembled core load time test

Test for the verification of Maximum Design Cantilever load (MDCL)-IEC-61952 clause-10.4

Type test addition A-7:Test on interfaces and connections

Thermo mechanical test as per IEC-61952 shall needed to be add in the RDSO standard with MDCL load (IEC-61952, clause-10.3.1).

Routine Test (addition) Clause-4.3

100% routine electrical testing of FRP Rod @175 V/mm and leakage current should be <0.05mA.

These parameters shall be specified by manufacturers in their QAP along with acceptance criteria.

Clause -3.3 (addition) Surface roughness of End fitting bore

End fitting roughness to be maintained in the range of Ra:4-10µm,Ry & Rz<60µm.

Drawing addition

Silicone rubber grade and manufacturer details/make in drawing approved.

Clause-3.3 Hardness test on end fitting (addition)

The maximum variation of hardness in a particular heat number should be maximum 20BHN. (This will ensure that for Insulator batch using end fitting from same heat have controlled crimping parameters.

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