MTO PROCEDURE
THIS SECTION BRIEFS OUT THE GENERAL PROCEDURE TO BE FOLLOWED FOLLOWED FOR MATERIAL MATERIAL TAKE-OFF. THE FOLLOWING IS A LIST OF INPUTS/REFERENCE DOCUMENTS WHICH SHOULD SHOULD BE KEPT READY PRIOR TO,AND FOR, THE PROCESS OF MATERIAL TAKE-OFF: • • • • • • • • • • • • • •
P&I D LINE LIST PIPING MATERIAL SPECIFICATION, APPROVED BY THE CLIENT MTO DATABASE APPROVED MTO SPARE PHILOSOPHY BRANCH TABLE BOLT TABLE VALVE LIST & SPECIALITIES LIST INSTRUMENT HOOK-UP DETAILS PLOT PLAN ( For For Preliminary MTO ) EQUIPMENT LAYOUTS ( For For Preliminary MTO) PIPING LAYOUTS ( For For Intermediate MTO) ISOMETRICS ( For Final MTO) KNOWLEDGE OF CRITICALITY OF THE PIPING – WHETHER THE PIPE IS TO BE IMPORTED/ EXPENSIVE, LONG DELIVERY AND, WHERE TO DRAW A LINE OF ACCURACY BETWEEN LARGE BORE/CRITCAL PIPE AND SMALL BORE/ LESS EXPENSIVE PIPES.
PROCEDURE: ϖ
FIND FIND OUT OUT THE TOTAL TOTAL LENGT LENGTH H INCLU INCLUDI DING NG ALL ALL ITEM ITEMSS- PIPE PIPES, S, FITT FITTIN INGS, GS, VALVES, OTHER SPECIALITIES, ETC.- AS SUCH FROM THE LAYOUT.
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IF THE PIPING IS ABOVE 80 NB OR IF THE PIPE MATERIAL IS VERY EXPENSIVE, THEN THEN ACCU ACCURA RACY CY OF THE THE ESTI ESTIMA MATE TE SHOU SHOULD LD BE GIVE GIVEN N UTMO UTMOST ST IMPORTANCE IMPORTANCE AND HENCE, THE FOLLOWING FOLLOWING STEPS SHOULD SHOULD BE STRICTLY STRICTLY ADHERED TO: ¬
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ESTIM ESTIMATE ATE THE THE NUMB NUMBER ER OF FITTI FITTING NGS S – ELBOW ELBOWS, S, TEES, TEES, REDUC REDUCERS ERS,, FLANGES, GASKETS, BOLTS & NUTS, ETC. ESTIMATE ESTIMATE THE NUMBER OF VALVES VALVES AND OTHER SPECIALITIES SPECIALITIES IN THE THE PARTIC PARTICULAR ULAR LINE. LINE. CHECK CHECK OUT THEIR THEIR END CONNECT CONNECTION IONS S WHICH WHICH WILL WILL STRAIGH STRAIGHT T AWAY AWAY GIVE GIVE THE NUMBER NUMBER OF FLANGES FLANGES,, GASKETS GASKETS,, BOLTS AND NUTS APART FROM THOSE ESTIMATED FOR EQUIPMENT AND OTHER INSTRUMENT CONNECTIONS. SUM UP THE LENGTH OF THE FITTINGS AND THAT OF THE VALVES AND OTHE OTHER R SPECI SPECIAL ALIT ITIE IES S AND AND DEDU DEDUCTI CTION ON OF THE THE SAME SAME FROM FROM THE THE TOTAL LENGTH WILL GIVE THE EXACT LENGTH OF PIPES.
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FOR PIPES 50 NB AND BELOW, THE TIME INVOLVED IN CALCULATING THE EXAC EXACT T LENG LENGTH TH OF PIPE PIPES S IS NOT NOT ALWA ALWAYS YS JUST JUSTIF IFIE IED D AND AND HENC HENCE E DEDU DEDUCTI CTION ON OF THE THE LENGTH LENGTH OF FITT FITTIN INGS GS AND AND OTHER OTHER ITEM ITEMS S IS NOT NOT ADVISA ADVISABLE. BLE. FOR JOINING JOINING TWO LENGTHS LENGTHS OF PIPE PIPE A FULL-CO FULL-COUPL UPLING ING IS NORMALLY EMPLOYED AND HENCE ONE FULL-COUPLING FOR EVERY 6m LENGTH OF PIPE, OR AS THE CASE MAY BE, SHOULD BE CONSIDERED.
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CARE CARE SHOU SHOULD LD BE TAKE TAKEN N TO ENSU ENSURE RE THAT THAT NO ITEM ITEM IS LEFT LEFT OUT OUT OR DUPLICATED ATED DUR DURING ESTI STIMATION AND THIS IS ENSURED RED BY
HIGHLIGHTING THE LINES IN THE P&I D. HOWEVER, THE SCOPE DEMARCATION BETWEEN PIPING & INSTRUMENTATION AND THE PIPING FROM THE UNIT AREA TO RACK AREA & VICE VERSA SHOULD BE DEFINED CLEARLY. ϖ
IN THE PRELIMINARY STAGES OF MTO, MOST OF THE QUANTITIES MAY HAVE TO BE ESTIMATED WITH THE HELP OF STUDY SKETCHES AND ASSUMPTIONS. THE BASIS OF MTO, THE ASSUMPTIONS MADE, REFERENCE AND INPUT DOCUMENTS , LINES/ITEMS NOT INCLUDED ETC., SHALL BE RECORDED AS NOTES AND SHALL FORM PART OF MTO. THIS WOULD HELP IN IDENTIFYING THE LEFT OUT ITEMS, REASONS FOR VARIATIONS ETC..
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HELP/ADVICE FROM THE LEAD ENGINEER/ DESIGNER SHOULD ALWAYS BE SOUGHT BY THE MTO ENGINEER WHENEVER THE LATTER FACES SOME PROBLEMS IN THE PROCESS OF ESTIMATION.
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ONCE THE MTO INPUT SHEETS ARE READY, THE SAME SHALL BE GIVEN TO THE PROGRAMMER FOR DATA ENTRY. THE INPUT THUS ENTERED SHALL BE VALIDATED WORD BY WORD WITH THE ORIGINAL MTO INPUT SHEETS.
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THE PROGRAMMER THEN TRANSFORMS THE ERROR-FREE MTO INPUT INTO MTO OUTPUT BY MAKING USE OF THE MTO DATABASE, MTO SPARE PHILOSOPHY, BRANCH TABLE AND BOLT TABLE. THE OUTPUT THUS OBTAINED WILL HAVE THE BULK QUANTITIES SORTED OUT EITHER LINEWISE OR SIZEWISE AND MATERIALWISE.
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THE ACCURACY OF THE OUTPUT THUS GENERATED WILL SOLELY DEPEND ON THE ACCURACY OF THE PROGRAM WHICH LINKS THE MTO DATABASE, SPARE PHILOSOPHY, BRANCH TABLE, BOLT TABLE FOR BULKING AND HENCE, THE PROGRAM SHOULD BE A VALIDATED AND TESTED ONE. OF COURSE, THE MTO DATABASE, SPARE PHILOSOPHY, BRANCH TABLE AND BOLT TABLE SHOULD ALSO BE THIROUGHLY VALIDATED BEFORE USING THE SAME FOR BULKING.
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THE FINAL OUTPUT IS THEN TRANSFORMED TO THE FORMAT APPROVED BY THE CLIENT.
THE ABOVE PROCEDURE HOLDS GOOD FOR ALL THE THREE STAGES OF MTO VIZ. PRELIMINARY, INTERMEDIATE AND FINAL. THE DIFFERENCE BEING THE INPUT AVAILABLE FOR ESTIMATING THE BOQ AND THE ACCURACY LEVEL OF THE BOQ ESTIMATED, WHICH IN TURN DEPENDS ON THE ACCURACY LEVEL OF THE INPUTS AVAILABLE (SUCH AS P&I D, LINE LIST, EQUIPMENT DATA SHEET AND PIPING LAYOUTS ETC.)
GENERALLY, THE ACCURACY LEVEL EXPECTED OF THE PRELIMINARY MTO WILL BE ABOUT 60%-70% AND THIS MTO IS PRIMARILY INTENDED FOR ARRIVING AT A ROUGH ESTIMATE OF PIPING COST AND VENDOR IDENTIFICATION. VALVE LIST CAN BE DEVELOPED WITH REASONABLE ACCURACY AT THIS STAGE IF THE P&I Ds AND LINE LIST FURNISHED ARE FAIRLY ACCURATE ( SAY 80% ACCURATE ) THE ACCURACY LEVEL OF INTERMEDIATE MTO WILL BE ABOUT 85% - 90% AS AT THIS STAGE THE EXPECTED LEVELS OF ACCURACY FOR P&I Ds AND LINE LIST WILL BE 90% AND THE PRELIMINARY PIPING LAYOUTS WOULD HAVE BEEN RELEASED FOR CLIENT’S APPROVAL ( ALL MAJOT LINES WOULD HAVE BEEN ROUTED )
THE FINAL MTO WILL BE PREPARED WITH ISOMETRICS AND APPROVED PIPING LAYOUTS. THIS MTO WILL HELP IDENTIFYING THE ADDITIONAL QUANTITIES DUE TO LAYOUT CHANGES, THE VENTS AND DRAINS AND MISCELLANEOUS LINES/ITEMS LEFTOUT IN THE PREVIOUS MTO STAGES.
