set of item no 1 2 for modification works as per rdso specn no rdso pe ms ac 0089 2002 rev 0 and hq lr no e 5 iii lhb dt 06 09 23 item no 1 differential pressure switches dps of pressure range from 0 08 1 20 inches wc shall be provided with more than 10 00 000 operations with automatic reset with ip 54 protection as per iec 60529 with ul 94 v0 qty 01 no per set item no 2 suitable length ss304 tube with id 4 0mm and 6 6 of od and length 1 173 mtrs to connect the differential pressure switch to