API 600 Valve Care and Maintenance Guide

Routine Maintenance and Inspection

Periodic visual inspection

Valve body and connections: Check the surface of the valve body for cracks, corrosion or signs of leakage every month, focusing on monitoring the sealing of flanges and bonnet bolts.

Valve stem and stuffing box: Observe whether the valve stem is bent or not, and whether the stuffing gland is loose (micro-adjustment is allowed to avoid over-compression).

Handwheel/actuator: Check the flexibility of the operating parts for any abnormal resistance or jamming.

Lubrication management

Valve stem and threads: Use high temperature lithium grease (in accordance with API 600) to lubricate valve stem threads every 3 months to prevent galling.

Gearbox/transmission mechanism: Replace lubricant and clean up old grease at regular intervals according to manufacturer’s manual.

Grease Filler Valve (if equipped): Replenish sealing grease through grease filler nozzle to maintain seat sealing.

Cleaning and corrosion protection

Remove oil and rust from valve surfaces during shutdown and clean with non-corrosive solvents.

Valves exposed to the environment should be coated with antirust coating to avoid salt spray and chemical erosion.

The operation specification and precautions

Opening and closing operation

Slowly rotate the handwheel during manual operation, and prohibit adding force with the help of lever to prevent the stem torque from exceeding the standard.

Rotate the handwheel back 1/4 turn after full opening/closing to avoid internal stress due to thermal expansion.

Pressure and Temperature Monitoring

Ensure that the working pressure does not exceed the rated Class rating of the valve (e.g. Class 1500).

High temperature conditions (>200°C) require monitoring of the stuffing box temperature to prevent failure of the sealing material.

Long-term out-of-service valve maintenance

Internal drying treatment

Empty the valve cavity medium, use dry nitrogen purge to prevent residual liquid corrosion.

Seal protection

Put the gate in half-open position to avoid long-term pressure and deformation of the valve seat.

Apply antirust grease to the flange surface and cover the protective cover.

Storage environment

Indoor storage should be kept ventilated and dry, relative humidity <60%; outdoor storage should be wrapped with waterproof cloth to avoid direct sunshine and rain.

Common Troubleshooting Recommendations