1.0 PURPOSE:
To describe a standard operating procedure for replacement of valves.
2.0 SCOPE:
The standard operating procedure describes in detail the method for replacing the valves in the plant.
3.0 RESPONSIBILITY:
The responsibility of replacing the valves lies with the staff of rank not lower than the junior utility operator
The responsibility of preparing, reviewing and approving the standard operating procedure lies with the Manager - Maintenance, Head of Production and Head of QAD respectively.
4.0 METHOD:
4.1 Ensure that there is no material in the line/receiver/reactor, where the valve is to be replaced and also ensure that the connected pumps are isolated electrically.
4.2 Loosen all bolts and remove them.
4.3 Remove valve along with gasket.
4.4 Clean both the flange surfaces using sharp edged blade.
4.5 Cut the gasket of suitable size.
4.6 Place the new/serviced valve in position and fix three bolts loosely on both the flanges (incase of reactors/receivers place the gasket on the valve flange and fix the bolts).
4.7 Insert gaskets from the fourth unbolted side.
4.8 Fix the fourth bolt on both the flanges.
4.9 Tighten opposite bolts evenly, ensuring that the gasket is centrally located.
4.10 Tighten all bolts.
4.11 Check for the leakage from valve and gasket.
4.12 If there is any leakage between the flanges tighten the bolts further till the leakage is arrested. If there is leakage from valve seat follow Step No. 4.1 to 4.11 to replace the valve.
Replacement of valves, utility operator, engineering
