Valve installation is a critical MEICA activity on water treatment, process, and infrastructure projects. Incorrect alignment or inadequate bolting can cause leaks under pressure, leading to flooding, chemical release, or catastrophic joint failure. Operatives must understand correct procedures for handling, aligning, and pressure testing valves safely on site.
Key Hazards
Crush injuries when manoeuvring heavy valves into position
Pressurised fluid release from incorrectly torqued flange bolts
Chemical exposure from leaking process valves during testing
Back injuries from manual handling of large gate and butterfly valves
Control Measures
Use mechanical lifting aids for all valves too heavy to safely handle by hand.
Check valve weight and dimensions before delivery to plan handling arrangements.
Align valve flanges carefully using guide bolts before inserting all fixings.
Torque flange bolts to the correct specification using a calibrated torque wrench in a star pattern.
Install the correct gasket type and grade as specified in the design documentation.
Conduct a visual inspection of all joints before authorising pressure testing.
Establish an exclusion zone around the test area during hydrostatic pressure testing.
Bleed off pressure gradually through designated vent points after testing is complete.
Record all test results and submit certification before the system is declared fit for service.
Remember
Always use mechanical lifting aids for heavy valves to prevent manual handling injuries
Torque all flange bolts to the correct specification in a star pattern sequence
Install the correct gasket type as specified in the engineering design documents
Establish exclusion zones around all pressure testing areas before pressurising
Never release test pressure suddenly; always bleed off gradually through vent points