BUREAU OF INDIAN STANDARD (Faridabad Branch Office)

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1 BUREAU OF INDIAN STANDARD (Faridabad Branch Office) Our ref: FRBO/9798:2013 Date Subject: Implementation of IS 9798:2013, Low Pressure Regulators for Use With Liquefied Petroleum Gas (LPG) and its revised STI:Doc STI/9798/6 January 2015 (draft STI) 1. FRBO has been advisedby CMD-II (legal) vide note reference CMD-II/16:9798 dated to examine the revised standard IS 9798:2013 Low Pressure Regulators for Use with Liquefied Petroleum Gas (LPG) Specification (Second revision) and prepare & finalize the STI and guidelines for implementation of revised ISS. 2. Based on review of revised Indian standard IS 9798:2013,FRBO has prepared a draft STI as Doc: STI/9798/6January 2015(Copy enclosed). 3. Vide circular no CMD-II/16:9798 dated 12/09/2014 and 29/10/2014 all RO s/ BO s were also requested to immediately bring the above revision in to the knowledge of all the licensees and applicants under their jurisdiction so that they may examine it and take action for its implementation and also to bring to the notice of FRBO the difficulties/comments, if any expressed by the licensees in implementing the revised standard along with their recommendations. No communications have been received at FRBO from any RO / BO as on date. 4. As per the above referred CMD II circulars, the prevailing version (i.e IS 9798:1995) will remain in force concurrently till 31 January 2015 and thereafter the same along with STI stands withdrawn. 5.For Application/Grant of licence cases a)all new applications are to be recorded as per IS 9798:2013. b) In cases where testing of samples are in progress or test reports are already received as per IS 9798:1995 version, grant of licence as per old version of the Standard(IS 9798:1995) can be processed after obtaining an undertaking from the firm for ensuring the change over to the revised standard by the date of implementationi.e 31 January In thesecases, changeover to the revised standard shall be processed as per existing guidelines for licences, by the implementation date. 6. For Existing Licence cases: a) A copy of the STI shall be sent to all licensees for their acceptance and comments, if any. b) All ROs/BOs are requested to inform the licensees under their jurisdiction about implementation of the IS 9798:2013 along with new STI. c)licensee should submit declaration regarding availability of additional manufacturing and test facilitiesand also test reports (in-house or OSL) for the conformity to all the requirements as per IS 9798:2013 for the varieties covered in the existing licence.ratings/types which do

2 not conform to the requirements of the specification shall be deleted from the scope of the licence w.e.f. the date of implementation given in the circular and necessary endorsement may be issued. d)endorsement in the license for revised IS 9798:2013and its STI shall be made after obtaining acceptance of revised STI. e) Availability of the additional facilities to be verified and additional tests as per revised IS be carried out during the lot inspection after submission of declaration by the firm. Surveillance visit shall be carried out within3 months from the date of implementation to verify the implementation of the revised standard. Any one variety/size may be tested for all possible tests in a day and based on satisfactory inspection sample (preferably of different variety/size, if available), to be drawn for independent testing. f) The case to be reviewed on receipt of independent test report. g) All inclusions to be considered as per revised IS 9798:2013 only. h) Action shall be taken as per OMPC 2004, if the licensee fails to submit the acceptance of STI in stipulated time or failure of sample in factory/independent testing. The revised and the old standard shall run concurrently till , after which theearlier version of the standard (IS 9798: 1995) and its STI shall stands withdrawn. All RO s/bo s are requested to bringthe above in to the knowledge of all the licensees and applicants for this product under their jurisdiction so that they may examine it and take action for its immediate implementation and to submit the difficulty/comments, if any, on this proposal and the enclosed STI before 10 January2015 so as to finalise the same. (S SMugali)) Sd/- Scientist-E(FRBO)

3 BUREAU OF INDIAN STANDARDS (Faridabad Branch Office) Our Ref.: FRBO/9798: Subject : Draft Scheme of Testing and Inspection for IS 9798:2013, Low Pressure Regulators for Use With Liquefied Petroleum Gas (LPG) and its STI document no: STI:Doc STI/9798/6 January 2015 (draft). Draft is as under: IS 9798:1995 has been revised and published as IS 9798:2013. In the revised specification following changes have been made:- (i) Terminology (clause 3) has been modified. Commercial butane, Commercial propane deleted. Commercial Butane/commercial propane mixure is termed as LPG. (ii) Material (clause 4) has been modified. Requirement for cover has been included. Body and cover shall now conform to IS 742. Material of construction of Body & Cover now restricted to Zinc base alloys only (clause 4.2). (iii) Compression set test (Clause 4.3.7, & 4.5) for Diaphragm, Valve and Seals material, respectively, incorporated. (iv) Body (clause 5.7.2) and Pressure Relief Valve (clause 5.9) both of 9798:1995 version deleted. (v) Requirements for excess flow valve (clause 5.9) incorporated; (iv) Strength of Connections test (clause 5.11) incorporated Consequent upon revision of IS 9798, draft STI has been prepared (copy enclosed) In the proposed draft following main changes/modifications are made. A) In text part: (i) Change in TITLE; (ii) Clause 2.1: for calibration of test instruments- traceability requirement added (iii) Clause 3.1: reference to IS/ISO 9000 series is replaced by IS/ISO 9001: 2008 (iv) Clause 4.1: Marking: a) Clause 4.1.c) Rated capacity in m3/h of gas designed for is replaced by Rated capacity, in m3/h of LPG b) Clause 4.1.e)- Name of the gas, designed for replaced by Number of this Indian Standard. (iv) Clause 5.0: Control Unit: Definition modified:- as

4 A CU shall consist of a lot of bodies and covers of the same type and size die cast in a day (covers and body may be die cast on different day) from the material of the same heat//supplier under similar process of production. B) In Table 1 Levels of control a) Re-grouping of tests under type test and routine test- in line with classification of tests given in clause 10 of revised version of IS b) Following additions are made; i) Compression set test - (clause & 4.4.5) ii) Seals - (clause 4.5) iii) Screwed Ends (clause 5.4, and 5.6.2). iv) Excess flow valve (clause 5.9, 8.10) v) Valve pad fitting - (clause 5.10) vi) Strength of connection - (clause 5.11, 8.11) vii) Sealing - (clause 9). viii) Marking-(clause11.1.d) - number of this Indian Standard. ix) Foot note 1of Table 1: Cross check of raw material at NABL approved laboratory introduced. x) Foot note 3 & 5 of Table 1: Added in line with the changes made in acceptance criteria in the revised IS 9798:2013 in clause 6.3 & 6.4. c) Deletions; i) Marking - Name of gas, designed for. d) Modifications; i) Marking (clause 11.1.c) - Rated capacity in m 3 /h of gas designed for changed to Rated capacity, in m3/h of LPG. ii) Clause 6.1.1: 2 nd sentence is deleted as the scope of IS 9798:2013 is only for LPG. iii) Clause 6.1.1, STI, Annex-B: In line with clause 6.1.1, Certificate is modified. At the top of certificate, Name and address of the manufacturer, is replaced by BUREAU OF INDIAN STANDARDS and related REGIONAL OFFICE iv) Clause and of existing STI merged and requirement of Seals (clause 4.5) included. v) Cycle test (clause ) - Sampling and frequency changed. vi) Foot note 2: Foot note 1 of existing STI, is now Note 2. vii) Foot note 4 of Table 1(note 2 of existing STI) - For cycle test, tests of cycles is done away with. Provision for release of lots of regulators based on tests conducted in previous week, in the event of non-completion of cycle test during the week of visit is made. Number of samples changed to 2.

5 viii)production data: Reference to enclosed proforma-i and affidavit/ undertaking is deleted. In place of proforma reference to CM/PF- 604 is made. e) Others: (i) Clause 5.9, Excess flow valve: Shown both in type test and routine test. As per classification (clause 10.1) this is type test. However, as per last para of Annex F, provision/method for routine test is stated. Hence, for purpose of routine test this para and for type test clause F3 is to be referred. C ) In Annex A (Lot inspection procedure): (i) In the first para, relation between Lot and Control units added/clarified. This allows for offering of one or more control units in to Lot and uniform practice by all branches. (ii) In Sampling size: Additional slab included. i.e, and above is made as to and additional sample size as and above added. (iii)in criteria for acceptance: Tests are grouped in two based on the nature of tests requiring 100% inspection on sample size and sub-sampling on sample size.. (One for tests to be carried out on entire sample size and another for sampling from sample size). (iv) Criteria for re-inspection, in case of failure of samples in selected sample size, are modified. This allows for re-offer for inspection on control unit basis. D) In Annex-B (Test Certificate); a) At the top of certificate: Manufacturer s name replaced by Bureau of Indian Standards, Regional Office b) In the test report part: (i) First sentence changed to include Lot no and Control unit nos in place of batch nos in line with modified definition of control unit and sampling procedure for Lot inspection (ii) Additional test i.e Excess flow valve and Mechanical Test of Connections included. PS: (i) Highlighted clauses in Table 1 are new additions in the revised STI Encl : as above. (S S Mugali) Sc-E, FRBO

6 DRAFT Draft:STI/9798/6 January 2015 SCHEME OF TESTING AND INSPECTION FOR CERTIFICATION OF LOW PRESSURE REGULATORS FOR USE WITH LIQUIFIED PETROLEUM GAS (LPG) ACCORDING TO IS 9798: LABORATORY: A laboratory shall be maintained which shall be suitably equipped and staffed where different tests given in the specification shall be carried out in accordance with the methods given in the specification. 2. TEST RECORDS: All records of tests, inspection and calibration shall be kept in suitable forms approved by the Bureau. 2.1 All testing apparatus/measuring instruments shall be periodically checked and calibrated and records of such checks/calibration shall be maintained. 2.2 Calibration of Testing instruments/equipments shall be carried out periodically from NABL accredited calibration laboratories wherever they are available in the same city. In case where such laboratories are not available, traceability to a National Measurement System (NPL) to be ensured. All records of such calibrations to be kept 2.3 Copies of any records and other connected papers that may be required by the Bureau shall be made available at any time on request. 3. QUALITY CONTROL: It is recommended that as far as possible, Statistical Quality Control (SQC) methods may be used for controlling the quality of the product during production as envisaged in this Scheme [See IS 397(Part I), IS 397(Part 2) and IS 397 (Part 3)]. 3.1 In addition, effort should be made to gradually introduce a quality Management system in accordance with IS/ISO 9001 series as appropriate to the activities of the organization. 4. STANDARD MARK: The Standard Mark, as given in Column (1) of the first Schedule of the licence, shall be marked on each low pressure regulators for use with LPG, provided always that the regulator to which this Mark is thus applied conforms to every requirement of the specification. 4.1 MARKING: In addition each regulator shall be provided with the following information on the regulator: a) The manufacturer s name or trade mark; b) The month and year of manufacture; 1

7 Draft:STI/9798/6 January 2015 c) Rated capacity in m 3 /h of LPG. d) Serial number of regulator, if required; e) Number of this Standard. f) Any other markings as agreed to between the purchaser and the manufacturer; and g) License Number (CM/L.) NOTE: The location and size of CM/L number to be marked on regulators is given in Annex D. 5.0 CONTROL UNIT: A CU shall consist of a lot of bodies and cover of the same type and size casted in a day from the material (body and cover can be cast on different days) of the same /supplier under similar process of production. 6.0 LEVELS OF CONTROL: The tests, as indicated in Table 1 attached and at the levels of control specified therein, shall be carried out on the whole production of the factory which is covered by this scheme and appropriate records and charts maintained in accordance with paragraph 2.0 above. All the production which conforms to the Indian Standards and covered by the licence shall be marked with certification mark of the Bureau. 6.1 Each control unit of finished regulators shall be offered for inspection to BIS before dispatch. The sampling and criteria of conformity for the lot inspection given in Annex A of this scheme shall be followed; Regulators failing to meet the requirements of the specification shall not be marked with the BIS Standard Mark A certificate shall be issued by the Bureau in respect of regulators approved for marking with BIS Standard Mark as per proforma given at Annex B. 6.2 The material shall conform to the requirements specified in Clause 4.1 and 4.2 of IS 9798:2013. A test certificate shall be supplied by the supplier for each of material. However, cross check is to be carried out once in month by testing samples at NABL approved laboratory Material of the diaphragm, valve pad & seals shall conform to the requirements as specified in clause 4.3, 4.4 and 4.5 respectively of IS 9798:2013. A test certificate shall be supplied by the supplier for each of material. The frequency of different tests shall be as indicated in Table The Bureau shall have the discretion of making an independent check test, if necessary, Material of body, cover, diaphragm, valve pad and seals. 2

8 Draft:STI/9798/6 January At the time of approval of prototypes, the regulator shall be checked, for conformity to all the requirements of IS 9798:2013. Whenever there is a change in material or design of the regulator, it shall be retested and shall conform to all the requirements of the specification. A drawing giving outline dimensions and materials of construction shall be provided along with the prototypes. 7.0 In respect of all other clauses of the specification and at all stages of manufacturer, the factory shall maintain appropriate control and checks to ensure that their product conforms to the various requirements of the specification. 8.0 REJECTIONS: A separate record shall be maintained giving information relating to the rejection of the production not conforming to the requirements of the specification and the method of its disposal. Such material shall in no circumstances be stored together with that conforming to the specification. 9.0 SAMPLES: The licence shall supply, free of charge, the samples required in accordance with the Bureau of Indian Standards (Certification) Regulations, 1988, as subsequently amended, from the factory or godowns. The Bureau shall pay for the samples taken by it from the open market REPLACEMENT: Whenever a complaint is received soon after the goods with Standard Marks have been purchased and used and if there is adequate evidence that the goods have not been misused, defective goods or their components are replaced or repaired free of cost by the licensee in case the complaint is proved to be genuine and the warranty period (where applicable) has not expired. The final authority to judge the conformity of the product to the Indian Standard shall be with the Bureau In the event of any damages caused by the goods bearing the Standard Mark, or claim being filed by the consumers against BIS Standard Mark and not conforming to the relevant Indian Standard, entire liability arising out of such non-conforming product shall be of licensee and BIS shall not in any way be responsible in such cases STOP MARKING: The marking of the product shall be stopped under intimation to the Bureau if, at any time, there is some difficulty in maintaining the conformity of their product to the specification, or the testing equipment goes out of order. the marking may be resumed as soon as the defects are removed under intimation of Bureau The marking of the product shall be stopped immediately if directed to do so by Bureau for any reason. The marking may then be resumed only after permission by the Bureau. The information regarding resumption of markings shall also be sent to the Bureau. 3

9 Draft:STI/9798/6 January PRODUCTION DATA: The licensee shall send to BIS production data duly authenticated by a Chartered Accountant at the end of every operative period as per item (b) of column 4 of the second schedule of the license, in the form CM/PF/604. Table 1. 4

10 Draft:STI/9798/6 January 2015 ANNEX A (Cl. 6.1 of STI) Subject: Sampling Plan for Lot Inspection for Certification of LPG regulators as per IS 9798:2013. All the regulators of the same size manufactured from the same of material under similar conditions of production shall be grouped together to constitute a lot. The lot may consist of one or more control units. Samples for lot inspection shall be selected depending on the number of regulators in a lot as given below: Lot Size Sample Size Upto & above 200 Note: When a lot consists of more than one control unit, the sample size shall be divided, as far as possible, equally between the control units Criteria for Acceptance of a lot (i) Each of the regulator selected in the sample shall be subjected to the following tests: a) Construction and workmanship (clause 5.2). b) Inter-changeability (Cl. 5.3). c) Pneumatic test (Cl. 6.2, 6.4). d) Performance test (Cl ). e) Chatter (Cl ). (ii) 2 regulators from the selected samples of each lot shall be tested for ; a) Knob operations (cl 5.2). b) Outlet connection : [2 for non-threaded (Cl ) & 10 % of sample size for threaded (5.6.2). c) Excess flow valve (5.9), if regulator is to be used with excess flow valve - (one Regulator) d) Hydrostatic test (Cl. 6.3). 5

11 e) Mechanical Strength of Connection (8.11). A regulator failing to meet any of the requirements of above tests shall be termed as defective. The lot shall be accepted if no defective is found in the sample size, In case of failure(s), the entire control unit(s) of the defective regulator(s) to be rechecked for the failed parameter and reoffered for inspection, after taking corrective action, wherever required. If a control unit has been re-offered, then the same sampling criteria should be applied as indicated above. but with double the sample size. 6

12 Draft:STI/9798/6 January 2015 ANNEX B (Cl of STI) BUREAU OF INDIAN STANDARDS (. REGIONAL OFFICE) TEST CERTIFICATE FOR LPG PRESSURE REGULATORS Certificate No. : Date: Name and address of the manufacturer: Batch No.(s) : Order No. & Date: Purchaser : Description: Low Pressure LPG regulator (Max. working Pressure kgf/cm 2 ) 500 l/h outlet for 6.4/7mm Rubber Tubing to be used on SC valves with 22.0/25.6 mm outlet diameter. This is to certify that the following regulators are inspected and tested on at M/s in accordance with Scheme Of Testing and Inspection attached with BIS License No. meet the requirement of IS 9798:2013 & drawing No. approved by Chief Controller of Explosives vide letter No. dated. Raw Material Specification: Supplier s Name: Chemical Composition (%) Test Cert. No. & Date: A1 Mg Cr Pb Fe Zn Impurities Specified As per T.C Remarks

13 Draft:STI/9798/6 January 2015 Regulators bearing serial Nos from to. covered by Lot no: and Control Unit nos. are checked/tested for the following: Sr No Parameter Clause No 1 Construction & workmanship (including knob operation) 2 Interchangeability Specified value/ or as per clause 3 Leak-proof test for inlet connection 4 Soundness test 6 4.a Pneumatic test (kg/cm 2 ) b Pneumatic test (gf/cm 2 ) c Hydrostatic test (kg/cm 2 ) Outlet Connection Chatter Performance test Delivery Pr. (mm of W.C) 7.a Inlet pr: 0.5 (kgf/cm 2 ) and min 100 % flow rate 7.b Inlet pr: 17 (kgf/cm 2 ) and max % flow rate 7.c Inlet pr: 17 (kgf/cm 2 ) and lock up max 8 Excess flow valve Mechanical Strength of Connection No of pieces inspected Result QUANTITY OFFERED: QUANTITY PASSED: SR. NO. OF REGULATORS REJECTED: Method of disposal of rejected regulators: De-shaped/Dismantled: Firm s Q.C. In charge NAME Designation Date BIS Inspecting Officer NAME Designation Date 8

14 ANNEX C (Table 1 of STI) Draft:STI/9798/6 January 2015 Interchangeability Procedure for Leak-proof test for inlet connection of LPG pressure regulator as per clause 5.5 IS 9798 and Table 1 of this Scheme. The manufacturer shall provide to the inspector two self closing spring loaded LPG valves manufactured as per customer s requirements, one with all tolerances on the minimum side and another with all tolerances on the maximum side for this check For checking proper fitment and locking up with self closing spring loaded LPG valves, regulators to be coupled with the two pieces of valves provided as above and hydrostatic/pneumatic tests carried out with the valve in open position at the pressure of 25.4 kgf/cm 2 /17.0 kgf/cm 2 to check that there is no leakage from the regulator inlet portion as also from the valve outlet and the regulator inlet joint (the regulator orifice to be closed to lock up position by applying pneumatic pressure greater than 450 mm of water column through outlet of regulator). 9

15 Clause no 4 Nature of test/ requirement Material 4.1 & 4.2 Body & Cover Material TEST DETAILS Test method/ clause no Reference IS IS 9798: 2013 LOW PRESSURE REGULATORS FOR USE WITH LIQUIFIED PETROLEUM GAS (LPG) TABLE 1 LEVELS OF CONTROL (Para 6.0 of the Scheme of Testing and Inspection) No of samples 4.1 & , 742 one Each LEVELS OF CONTROL Lot Size Frequency DRAFT STI IS 9798 :2013 Remarks Each See Note Components material one do do do Brass parts , 2305 one do do do 5.2, 5.3 Construction 5.2, Each regulator 9 Sealing Each regulator 4.3 Type Tests Diaphragm Material Porosity and surface smoothness % subject to a minimum of 8 All the Diaphragm of the same quality in a Each lot See note Clamping test Ageing/Hardnes s or (pt 4) one do do Test to be carried out on representative slab/ button. See note Clamping test one do do See note Pull out and burst Annex C 9798 One sample Per 1000 All the regulators Regulators or assembled Part thereof. in one day Daily See note 2

16 Clause no Nature of test/ requirement TEST DETAILS Immersion test for diaphragm Test method/ clause no Annex D C Reference IS 9798: 2013 LOW PRESSURE REGULATORS FOR USE WITH LIQUIFIED PETROLEUM GAS (LPG) TABLE 1 LEVELS OF CONTROL (Para 6.0 of the Scheme of Testing and Inspection) No of samples 9798 one 1000 diaphragm LEVELS OF CONTROL Lot Size Frequency DRAFT STI IS 9798 :2013 Each lot Remarks See note Flexible test one 1000 diaphragm Compression set test 4.3.7, Annex E 9798 one Each lot Each lot Each lot See note 2 Test to be carried out on representative slab/ button. 4.4 Valve pad Material Porosity, pits,surface smoothness, low cold flow, creep characteristic % subject to a minimum of 8 All the Diaphragm of the same quality in a Each lot See note Immersion test for valve pad Annex D 9798 one 1000 valve pad Each lot See note Immersion test for valve pad fitted in its housing one 1000 valve pad fitted in its housing 4.5 Seals percent subject to a minimum of 8 O rings & rubber components other than diaphragm & valve pad of the same quality in & 6.3 Hydrostatic Test & Each control unit 5.7 Body Each control unit 5.9, 8.10 Excess flow valve 5.9, 8.10, 9798 one One control Annex-F(F3) unit Each lot See note 2 do See note 2 Each control unit Note 3 Each control unit once a month

17 Clause no Nature of test/ requirement TEST DETAILS Test method/ clause no Reference IS 9798: 2013 LOW PRESSURE REGULATORS FOR USE WITH LIQUIFIED PETROLEUM GAS (LPG) TABLE 1 LEVELS OF CONTROL (Para 6.0 of the Scheme of Testing and Inspection) No of samples 5.10 Valve pad fitting one Once in six month LEVELS OF CONTROL Lot Size Frequency DRAFT STI IS 9798 :2013 And at the time of type approval or whenever there is change in design. Remarks 5.11, 8.11 Strength of connection 5.11, one -- do do Cycle test Weeks production Low temp test Weeks production High temp test Weeks production Routine tests Each week. See note 4 Each week. Each week Finish Corrosion resistance Finish (Adhesion test for painted or powder coated surface) , Annexue B one one control unit 9798 one one control unit Each week. one control unit Compression set Annex E Ageing test/ Hardness 4.5 Porosity.Ageing 4.4.1,4.4.3, /Hardness/Compre ssion set 9798 one Each 3 or (Pt.4) one do Test to be carried out on representative slab/button percent subject to a minimum of 8 5.4, Screwed Ends Annex E 9798 Each regulator do do

18 Clause no Nature of test/ requirement 5.5 Interchangeability/ Leakproof test for inlet connection 5.5.2, 6.2 & 6.4 Test method/ clause no Annex- C of STI Reference No of samples 0.25 percent subject to a minimum of 8 Pneumatic test 5.5.2, Each & 6.4 regulator 5.6 Outlet connection (non threaded) 5.6 Outlet connection (threaded) 5.9 Excess flow valve 5.9, Annex-F (F 2 & last para) 8.2, 8.9 Chatter & Performance TEST DETAILS IS 9798: 2013 LOW PRESSURE REGULATORS FOR USE WITH LIQUIFIED PETROLEUM GAS (LPG) TABLE 1 LEVELS OF CONTROL (Para 6.0 of the Scheme of Testing and Inspection) LEVELS OF CONTROL Lot Size Frequency All the regulators assembled in a day Each control unit Each regulator Each control unit 8.2, Each regulator DRAFT STI IS 9798 :2013 Each control unit Each control unit Remarks Note 5 Suitable gauges to be arranged....do Note 1: Note 2: Note 3: Note 4: Note 5: In case material is received with test certificate indicating conformity to chemical composition of relevant IS no further testing is required. However, cross check is to be carried out once in month by testing samples at NABL approved laboratory. If any of the sample fails, twice the number of samples shall be tested from the same. In case of further failures, the entire (lot) shall be rejected. In case of any change in back pressure it shall be construed as leakage through the pad/body and treated as failure of the regulator. In such case, thrice the number of fresh samples shall be tested from same lot. In case of further failures, the entire (lot) shall be rejected. In the event of non completion of the test at the time of inspection by BIS in a particular week, cycle tests carried out during immediate previous week may be accepted. Test results of on going cycle tests to be shown to BIS in succeeding visit. For clause 6.4, in case of any change in back pressure it shall be construed as leakage through the pad/body and treated as failure of the regulator. In such case, further investigation to be carried out to asertain the reason for failure and action to be taken accordingly, and quality check to be strengthened in the affected area.

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