How to carry out daily maintenance and cleaning after installing stainless steel ventilation pipes?

Specification for routine maintenance and cleaning of stainless steel ventilation pipes

The core goal of daily maintenance and cleaning of stainless steel ventilation pipes is to maintain the tightness, patency and corrosion resistance of the pipes, prolong the service life and ensure the operating efficiency of the ventilation system. The following are the operating specifications of sub-modules, which can be directly used in the field operation and maintenance manual:

I. Daily inspection and maintenance (once a week, basic guarantee)

Appearance and sealing inspection

Inspect the welded joint, flange joint, elbow and reducing part of the pipeline to see if there are any problems such as weld cracking, flange gasket aging and screw loosening. If the weld rust is found, it shall be cleaned with special rust remover for stainless steel in time, and then painted with stainless steel anticorrosive paint.

Check whether the pipeline supports and hangers are firm, loose and deformed, so as to prevent the pipeline from sinking, dislocation and damage to the sealing structure due to the failure of the supports.

Smear the flange and weld with soapy water, observe whether there are bubbles after opening the ventilation system, and judge whether there is air leakage. The air leakage point should be fastened or replaced in time.

Linkage inspection of fan and valve

Check the connection parts between the air duct and the fan and air valve to ensure that the soft joint is not damaged or dropped off, and to avoid the joint cracking caused by vibration.

Linkage test the flexibility of the air valve switch to ensure that the valve blades are not stuck and closely attached to the inner wall of the air duct, so as to prevent the air distribution from being affected by air leakage of the valve.

Drainage device maintenance

If the air duct is provided with a condensate drain (for use in a high humidity environment), it is necessary to clean the drain valve and the sump every week to prevent sludge and sundries from clogging and prevent condensate from accumulating in the pipeline and causing local corrosion.

Second, regular cleaning operations (monthly/quarterly, graded as needed)

The cleaning frequency should be adjusted according to the use environment: once a month in places with high dust concentration (such as building materials warehouses and chemical fiber workshops); Ordinary clean places once every quarter.

(a) dry cleaning (suitable for loose dust in the pipeline)

preparatory work/be about to work

Turn off the power supply of the ventilation system, wear dust masks and gloves, and open the access ports at both ends of the air duct (when there is no access port, the flange joint can be temporarily removed).

Prepare industrial vacuum cleaner (with extended hose and brush head), stainless steel special brush, rag and other tools.

Cleaning steps

Use stainless steel brush to gradually clean the dust on the inner wall from one end of the air duct to the other end to avoid dust flying; At the same time, the industrial vacuum cleaner is used for synchronous suction, and the dust is collected into the dust bag.

Focus on cleaning the dead corners of air flow such as elbows, tees and reducer, which are easy to accumulate dust and need to be brushed repeatedly.

Wipe the inner wall of the air duct with a dry rag to remove residual floating dust; Wipe the sealing surface of the flange to ensure that the sealing surface is clean and free of sundries.

Finishing work

After cleaning, check whether there is any scratch or corrosion on the inner wall of the air duct. If there is any slight scratch, use polishing paste to polish and repair it.

Reinstall the manhole or flange, and tighten the screws with even force to prevent air leakage caused by uneven stress on the gasket.

(2) Wet cleaning (applicable to the case of dust adhesion or oil contamination in the pipeline)

preparatory work/be about to work

Turn off the power supply, remove the air duct access port, lay waterproof cloth under the pipeline, and place the water receiving basin to prevent sewage leakage.

Dispose of cleaning solution: neutral cleaner+warm water (strong acid and strong alkali cleaners are strictly prohibited to avoid corrosion of stainless steel surface); When the oil pollution is serious, special degreasing agent for stainless steel can be selected.

Cleaning steps

Spray the cleaning solution on the inner wall of the air duct with a high-pressure water gun (the pressure is controlled at 0.3~0.5MPa) or a watering can, and soak for 5~10 minutes to soften the dirt.

Brush the inner wall with nylon brush (steel ball is forbidden to prevent scratching the stainless steel passivation film) to remove the bonded dust and oil stain; Sewage is discharged into the basin through the drain.

Rinse the inner wall of the air duct with clean water until the flowing water is clear and foam-free, so as to ensure that there is no residual detergent (residual detergent will cause local corrosion).

drying process

Turn on the fan of the ventilation system and run for 1-2 hours to dry the moisture in the air duct; Or use an industrial blower to blow dry at the inspection port to avoid corrosion caused by residual moisture in the pipeline.

(3) Cleaning of special scenes (such as corrosive gas environment)

For the air duct conveying corrosive gas, a layer of stainless steel passivation paste should be evenly coated on the inner wall after cleaning to form a protective film to enhance corrosion resistance;

Every six months, the inner wall of the pipeline is fully maintained with passivation paste to repair the passivation film.

Three, seasonal maintenance (twice a year, seasonal focus)

Maintenance before rainy season

Check whether the outdoor wind pipe rainproof cap is in good condition, and whether the flange seal is equipped with rainproof rubber strip to prevent rainwater from infiltrating into the pipeline.

Anticorrosive treatment shall be carried out for pipeline supports and hangers, and antirust paint shall be applied to avoid the corrosion failure of supports caused by humidity in rainy season.

Maintenance before winter

For the cold area in the north, check whether the insulation layer of the air duct is in good condition to prevent the condensed water in the pipeline from freezing and expanding and damaging the pipeline structure.

Drain the accumulated water in the drain and close the valve of the outdoor air duct to prevent the cold air from flowing backwards and affecting the indoor ventilation effect.

Fourth, maintain clean taboos

It is forbidden to use hard tools such as steel ball and sandpaper to wipe the stainless steel inner wall, so as not to destroy the surface passivation film and cause corrosion;

Avoid using strong corrosive cleaners such as hydrochloric acid and caustic soda, and rinse thoroughly with clean water after cleaning;

When cleaning, it is forbidden to trample on the pipeline body to prevent the pipeline from deformation;

When the ventilation system is running, the manhole or flange shall not be removed to prevent the dust entrained in the airflow from being ejected, which may cause potential safety hazards.