PV Valve DN200 SS316L Marine

Common issues

• Pallet/seat fouling from cargo vapour residue or icing, preventing proper seating
• Corrosion of valve body or pallet reducing set-pressure accuracy
• Seal (PTFE/elastomer) degradation causing leakage past the seat
• Set-pressure drift from spring fatigue or mechanical damage
• Flame screen blockage from product buildup, if fitted
• Pallet sticking from lack of lubrication or paint overspray during maintenance
• Drain hole blockage leading to water/condensate accumulation

Inspection checklist

• Visual check for external corrosion or damage to body and flange
• Manual lift/pop function test to confirm free pallet movement
• Check flame screen, if fitted, for blockage or damage
• Verify set pressure/vacuum on a test bench against the valve's own nameplate/certificate - do not assume a catalogue figure
• Inspect seat and pallet sealing surfaces for pitting or deposits
• Check drain holes are clear
• Confirm the valve tag/certificate matches its installed location and cargo service
• Inspect gaskets and fasteners for corrosion

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Seat/pallet seal (PTFE or elastomer)
• Spring set matched to the required set pressure
• Flame screen element
• Gasket set

Safety

• Flammable/toxic vapour release at the vent outlet during testing
• Working at height on deck or vent riser
• Stored spring energy during disassembly
• Cargo vapour exposure - gas-test and use appropriate PPE before close approach
• Static discharge risk near cargo vent openings

Class survey

Note: the specific set-pressure and vacuum figures in the sourced specification are flagged as unverified and are not restated here as fact. PV valves for cargo tank venting are class/flag-surveyed items requiring approved test certificates, set-pressure verification traceable to type approval, and functional testing at the interval set by the vessel's approved maintenance system, typically tied to cargo tank venting system survey.