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IS 2372: Timber for cooling towers - PDF

2004·0.98 MB·English
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इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 2372 (2004): Timber for cooling towers - [CED 9: Timber and Timber Stores] “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda ““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee”” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 2372:2004 ~@am ( F ) Indian Standard TIMBER FOR COOLING TOWERS - SPECIFICATION (Second Revision) ; i I , Ics 79.040 1 0 BIS 2004 BUREAU OF INDIAN STANDARDS II MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 I I September 2004 Price Group 1 Timber and Timber Stores Sectional Committee, CED 9 FOREWORD This Indian Standard (Second Revision) wasadopted bythe Bureau ofIndian Standards, after the draft finalized by the Timber and Timber Stores Sectional Committee, had been approved by the Civil Engineering Division Council. This standard was first published in 1963. Based on the experience gained inthis field, itwas revised in 1991. Permissible defects indifferent grades oftimber for cooling towers were alsorationalized and the standard was brought inuniformity with the style of other standards ongrading oftimber. Inthis revision arational approach has been made with respect to permitted defects. For the purpose of deciding whether aparticular requirement ofthis standard iscomplied with, the final value, observed orcalculated, expressingtheresultofatestoranalysis,shallberoundedoffinaccordance withIS2:1960 ‘Rules forrounding offnumerical values (revised)’. Thenumber ofsignificant places retained intherounded off value should be the same asthat ofthe specified value inthis standard. IS 2372:2004 Indian Standard TIMBER FOR COOLING TOWERS — SPECIFICATION (Second Revision) 1SCOPE Table 1Timbers for Cooling Towers (Clause 4) This standerd covers the species, grades,requirements and treatments for timber used inthe construction of S1No. Botanical Name Trade Name cooling towers. (1) (2) (3) 2REFERENCES O Abiespirrdrow fir ii) Cedrus ahalara deodar The standards listed below contain provisions which, iii) Picea smithiarra spruce through reference inthistext, constitute provisions of iv) Pinus kesiya khasipine this standard. At the time of publication, the editions @ Pinus roxburghii chir indicated were valid. All standards are subject to vi) Pinus wallichiana kail revision, and parties to agreements based on this vii) Pseudotsuga tczrl~olia doughs fir viii) Pinus radiata radiatapine standard are encouraged to investigate the possibility ix) Tectoirograrrdis teak of applying the most recent editions of the standards indicated below: namely, select grade, Grade Iand Grade IIdepending onthe defects permitted (see 5.3). ISNo. Title 401:2001 Preservation of timber — Code of 5.2 Prohibited Defects (for All Grades) practice ~ourth revision) Timberwithloosegrain,reaction wood,heartwood rot, 707:1976 Glossary of terms applicable to warp, worm holes which are likely to affect strength, timber technology and utilization pitch pockets, centre heart (pith), shakes twisted grain (second revision) andwane shallnotbe selected for cooling towers. 3 TERMINOLOGY 5.3Permissible Defects 3.1 Forthepurpose ofthisstandard,t hedefinitiongiven The defects to the extent specified in Table 2 for inIS 707, andthe following shall appl y. different grades oftimber shall be permissible. 3.1.1 Columns 6DIMENSIONS AND TOLERANCES The main vertical supporting members in the tower 6.1 The suggested nominal sizes, rough and finished framework. dimensionsforvariousthicknessesaregiveninTable3. 3.1.2 Fill — These are either splash bars or splash 6.2 Tolerances slats. Splashing of water takes place on these bars A 5-mm tolerance in length shall normally be or slats. permissible. Inother dimensions, nominus tolerances 3.1.3Joists and Beams —Horizontal supports forlive shall be permitted but a maximum plus tolerance of anddead loads, suchassupports for fandeckflooring, 2mm shall bepermitted. filling drift eliminator, cold and hot water collecting 7TREATMENT and redistributing basins, water troughs, piping and mechanical equipment. The following treatments arerecommended: 4SPECIES OF TIMBER a) Thestmcturalmembersandtheshellmembers aretobetreated toanetretention of 12kg/m3 Thespecies oftimber suitable forcooling towers shall oftimberwithcopper-chrome-arsenic (CCA) be asgiven inTable 1. oracid-copper-chrome (ACC) or 16kg/m3of copper-chrome-boron (CCB) or 128 kg/m3 5GRADING OF TIMBER of creosote/fuel oil mixture in accordance 5.1 Cooling tower timbers shall be of three grades, with IS401. 1 IS 2372:2004 Table 2Permitted Defects for Different Grades ofTimber for Cooling Towers (Clause 5.3) sl Defects SelectGrade Grade 1 Grade 11 No. (1) (2) (3) (4) (5) i) Slopeofgrain Slope of grain shall notexceed Slopeofgrainshallnotexceed1 Slopeofgrainshallnotexceed 1 Iin18 in12 in8 ii) Knot/Knothole Both on narrow and wide face Both on narrow and wide face Both on narrow and wide face up to 15 mm, the diameter of up to 50 mm, the dhneter of up to 50 mm, the diameter of knotsshallnotbemorethanone knotsshallnotbemorethanone knotsshallnotbemorethanone fifthoftheface.Beyond50mm fifihoftheface.Beyond50mm fifthoftheface.Beyond50mm facethe diameterofknotsshall facethediameterofknotsshall facethediarnetefofknots shall not be more than one sixth of not bc more than one sixth of notbemorethanonefifthofthe theface.Suchknotsshallnotbe theface.Suchknotsshaflnotbe face. Such knots shall not be more than one per any given more than one per any given more than two per any given 1.5mlength 1mlength 1mlength iii) Check Checkupto3mmindepthshall Checkupto5mmindepthshafl Checks up to 5 mm in depth berdlowed besallowed shaflbeallowed iv) Endsplit End split shall bepermitted up End split shaflbe permitted up End split shall be permitted up to 150mmoneitherendsubject to150mmoneitherendsubject to 150mmoneitherendsubject to maximum 25 percent of to maximum 33 percent of to maximum 33 percent of overalllength overrdllength overalllength Table 3 Nominal and Dressed Dimensions Table 4 Depth of Penetration of Preservative in (Clause 6.1) Different Species of Timber All dimensions inmillimetres. (Clause 7.1) Nominal Rough 25 32 38 50 75 over100 sl Botanical Name Depth, Min. Thickness orWidth No. T Minimum Rough Sawn 23 30 35 47.5 72.5 off5 Sapwood Heartwood Thickness orWidth (Percent) Dressed Thickness or 21 27 32 45 70 Offlo (1) (2) (3) (4) Width i) Abies pindrow 100 5mm’) ii) Cedrus deodara 100 10mm b) Fill is to be treated under pressure with a iii) Pseudotsuga tarfolia 100 5mm’) minimum average retention of 16kg/m3 of iv) Picea smithiana 100 5mm’) timber with copper-chrome-arsenic (CCA)or v) Pinus kesiya 100 20mm vi) Pinus radiata 100 20mm acid-copper-chrome (ACC) or 20 kg/m3 of vii) Pinus roxburghii 100 20mm copper-chrome-boron (CCB) or 160kg/m3 viii) Pinus wallichiana 100 10mm of creosote/fuel oil mixture in accordance ix) Tectona grandis 100 Needsno treatment with IS 401. 1)Fors~c~r~ memberincisionabout15mmshouldk made 7.1 Penetration of Preservatives on all surfaces (except end ) to achieve the required. The depth of penetration of the preservative shall be absorption. asgiven in Table 4. . 2 Bureau of Indian Standards BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters inthe country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed tothe Director (Publications), BIS. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed periodically; astandard along with amendments isreaffirmed when such review indicates that no changes are needed; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standards should ascertain that they are inpossession ofthe latestamendments oredition by referring tothe latest issue of ‘BIS Catalogue’ and ‘Standards: Monthly Additions’. This Indian Standard has been developed from Doc :No. CED 9(6025). Amendments Issued Since Publication Amend No. Date of Issue Text Affected BUREAU OF INDIAN STANDARDS Headquarters : Manak Bhavan, 9Bahadur Shah Zafar Marg, New Delhi 110002 Telegrams :Manaksanstha Telephones :23230131,23233375,2323 9402 (Common toalloffices) Regional Offices : Telephone Central : Manak Bhavan, 9Bahadur ShahZafar Marg 23237617 1 NEW DELHI 110002 { 23233841 Eastern : 1/14C.I.T. Scheme VII M,V. LP.Road, Kankurgachi 23378499,23378561 KOLKATA 700054 { 23378626,2337 9}20 Northern : SCO 335-336, Sector 34-A, CHANDIGARH 160022 603843 609285 { I Southern :C.I.T. Campus, IVCross Road, CHENNAI 600113 22541216,22541442 22542519,22542315 { Western :Manakalaya, E9 MIDC, Marol, Andheri (East) 28329295,28327858 MUMBAI 400093 28327891,28327892 {.. Branches : AHMEDABAD. BANGALORE. BHOPAL. BHUBANESHWAR. COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. LUCKNOW. NAGPUR. NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANANTHAPURAM. VISAKHAPATNAM. PtmtedatPrabhatOJXsetPress, New Delhi-2

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