Dear All, Can any body let me know , how to select number of thickness monitoring locations in a piping circuit. Is there any formula or calculation for determining the number of TMLs to be monitored. REgards, Mumtaz

Mumtaz Thickness monitoring locations in a piping circuit - has to be governed by: 1. pressure 2. temperature 3. material used 4. corrosive nature of fluid in the system 5. velocity 6. liquid / gas phase 7. orifices / reducers / bends/ stagnant end caps/ other restrictios 8. statutory compliance with reference to applicable factory / explosive or corrosive process system given by licensors Selection is done to cover entire piping circuit once in four years - including bends, reducers, direction change locations, cold or hot insulated areas, straight portions - normally to start with once a meter distance, pumps or compressor discharge or suction areas, dampeners or scrubbers etc. After first monitoring, select areas where discrepancy in thickness is noted (allowing for piping thickness variation tolerance - usually thickness tolerance is 12.5% + or minus) and re monitor these areas carefully again before choosing new areas to cover the entire piping circuitry in four years. If Corrosive fluid or material change or temp or pressure variation had occurred during first and second monitoring, then choose new areas or locations to confirm monitored areas done did not have high discrepancies in reading values. With this careful selection, you will be able to predict and prevent corrosion related effects - including external and internal corrosion effects - in any piping circuiry Hope this helps C.V.Srinivasan Nishi Engineers Pvt Ltd India E-mail: nishi@vsnl.com >Dear All, > >Can any body let me know , how to select number of thickness >monitoring locations in a piping circuit. Is there any >formula or calculation for determining the number of TMLs to >be monitored. > >REgards, > >Mumtaz