Pneumatic hoists in operation are prone to corrosion of metal components and aging of seals due to prolonged exposure to complex environments such as humidity, corrosive gases, and high temperatures, which can affect the lifespan and safety of the equipment. The following systematically elaborates on corrosion prevention methods from five aspects: material selection, structural design, protective technology, environmental control, and maintenance management:

1、 Material selection and anti-corrosion treatment

Application of corrosion-resistant materials

Main structure: Stainless steel (such as 304, 316L) or aluminum alloy materials are preferred, suitable for high corrosion environments such as chemical and marine industries.

Key components: Friction parts such as chains and gears are made of galvanized steel or nickel based alloys, balancing strength and corrosion resistance.

Sealing element: FKM or PTFE material is selected to resist acid, alkali, and solvent corrosion.

Surface protection treatment

Hot dip galvanizing: hot-dip galvanizing carbon steel components to form a dense zinc layer that is resistant to salt spray corrosion (such as outdoor use).

Spray coating process: using a combination of epoxy zinc rich primer and polyurethane topcoat, with a coating thickness of ≥ 80 μ m, suitable for industrial plant environments.

Dacromet treatment: chromium free zinc aluminum coating, suitable for scenarios where hexavalent chromium pollution needs to be avoided (such as the food processing industry).

2、 Structural optimization and sealing design

Anti water accumulation structure

The gourd shell is designed with inclined drainage channels to prevent rainwater accumulation.

The chain guide groove adopts a closed structure to reduce the intrusion of dust and moisture.

Sealing system upgrade

Pneumatic motor sealing: using a combination of double lip oil seal and dust ring to prevent oil mist and impurities from entering the compressed air.

Brake protection: The brake disc is equipped with an external protective cover to prevent corrosive liquids from splashing.

Waterproof connector: IP67 waterproof connectors are selected for electrical connectors to avoid short circuits caused by moisture.

3、 Environmental control and protective measures

Ventilation and dehumidification

Install dehumidifiers in damp workshops to maintain an ambient humidity of ≤ 60%.

When parking the pneumatic hoist, use a desiccant pack to absorb internal moisture.

Local protection

Coating protection: Apply anti rust oil or vapor phase rust inhibitor to easily corroded areas such as welds and bolt connections.

Sacrificial anode method: Installing zinc blocks on metal structures to protect the main body through electrochemical principles.

Cleaning and maintenance

Wipe the surface of the equipment with a dry cloth after daily homework to remove corrosive media (such as acid and alkali droplets).

Regularly blow the chain, gears, and other parts with low-pressure air to prevent dust accumulation.

4、 Maintenance management and operational standards

Lubrication and maintenance

Chain lubrication: Apply corrosion-resistant grease (such as lithium grease+molybdenum disulfide) every month to reduce friction and oxidation.

Pneumatic system: Replace the air filter element every quarter to ensure that the compressed air is dry (dew point ≤ -40 ℃).

regular testing

Coating thickness detection: Use a coating thickness gauge to check the protective layer annually, and promptly apply additional coating if the thickness is insufficient.

Ultrasonic thickness measurement: Conduct wall thickness testing on key parts (such as main beams) to warn of corrosion and thinning.

Operation taboos

It is prohibited to work outdoors in rainy or humid environments. If necessary, a rain cover must be installed.

Avoid direct contact with corrosive liquids and use isolation pads when lifting chemical containers.

5、 Emergency response and repair

Initial treatment of rust

When slight rust spots are found, use sandpaper to polish to a metallic luster, and apply anti rust primer and topcoat.

Soak the chain in rust remover for 10 minutes, then clean and dry it, and re lubricate it.

Severe corrosion repair

When the main structure is corroded and perforated, stainless steel plate welding is used for repair, and penetration testing is carried out after welding.

When the sealing element ages and leaks, immediately replace it with the same type of accessory to avoid compressed air carrying water.

6、 Case reference and standard basis

Application in the chemical industry: A certain chemical plant uses 316L stainless steel pneumatic hoists, combined with epoxy coating, which can be used for 5 years in a chlor alkali environment without corrosion.

Marine platform case: The offshore platform uses hot-dip galvanized and Dacromet double protection chains, and has passed the salt spray test for 1000 hours.

Standard compliance: Refer to GB/T 3811-2008 "Code for Design of Cranes" and ISO 12944 "Protective Coating System for Steel Structures" to ensure compliance of the protection scheme.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment