Check Valve
1. Manufacturing defects in valve body, seat, disc, and stem.
2. Defects in pneumatic actuator cylinder and piston under normal service.
3. Faulty assembly leading to air leakage within actuator housing.
4. Failure of factory-installed limit stops or guiding mechanism.
1. Damage from contaminated or moist compressed air supply.
2. Seals, diaphragms, O-rings, and packing considered consumables.
3. Failure due to wrong alignment of actuator with valve.
4. External control accessories (solenoid valves, FRL units, tubing) unless specifically supplied under contract.
1. Casting or forging defects in valve body, bonnet, or actuator housing.
2. Leakage from hydraulic actuator cylinder due to faulty manufacturing.
3. Malfunctioning due to improper machining of guiding or seating surfaces.
4. Failure of manufacturer-installed hydraulic seals under normal fluid conditions.
1. Damage caused by contaminated hydraulic fluid or improper fluid grade.
2. Wear of seals, packing, O-rings due to normal service life.
3. Failure due to over-pressure surges beyond rated design.
4. External hydraulic power packs, hoses, and fittings unless supplied as part of the valve package.
1. Manufacturing defects in body, bonnet, or disc.
2. Faults in welding, casting, or machining.
3. Leakage through the body caused by defective materials.
4. Failure of supplied seals/liners within the warranty period (not due to misuse).
5. Actuator defects (if supplied with valve) caused by design or workmanship.
1. Wear and tear of seals, packing, or seats due to normal operation.
2. Damage caused by abrasive, corrosive, or slurry media beyond design specification.
3. Improper installation, alignment, or operation outside rated pressure/temperature.
4. Damage due to lack of maintenance or use of non-genuine spare parts.
5. Surface corrosion, erosion, or scaling caused by operating environment.
6. Modification of valve without manufacturer’s approval.
1. Defects in structural frame, gate leaf, or guides due to poor materials/workmanship.
2. Improper sealing due to manufacturing defect in seating surfaces.
3. Corrosion protection (coating/lining) failure due to defective application.
4. Gearbox, spindle, or hoist mechanism defects if provided by manufacturer.
1. Normal wear of seals, wedges, or seating surfaces.
2. Damage due to silt, grit, or foreign objects obstructing gate movement.
3. Improper installation, foundation settlement, or misalignment of guides.
4. Operation under water head or flow conditions beyond design specification.
5. Lack of lubrication/maintenance of hoist mechanism.
6. Damage due to unauthorized modification, welding, or structural changes.