What should be paid attention to in the maintenance of water treatment valves?

1. Cleaning of valves.

The surface of the valve, the trapezoidal thread on the stem and stem nut, the sliding part of the stem nut and the bracket, as well as the gear, worm gear and worm and other parts are easy to be contaminated with a lot of dust, oil and medium residues and other stolen goods, which will cause wear and corrosion to the valve. Therefore, it is necessary to keep the outside of the valve and the moving parts clean; Protects the integrity of the valve paint.

2. Lubrication of valves.

The trapezoidal thread of the valve, the sliding part of the stem nut and the bracket, the bearing part, the meshing part of the gear and worm gear, the worm part and other mating parts all require good lubrication conditions to reduce friction and avoid mutual wear. The lubrication parts should be lubricated regularly according to the specific situation.

3. Maintenance of valves in operation.

Valves in operation, all kinds of valves should be complete and intact. The bolts on the flange and bracket are indispensable, and the threads should be intact and not allowed to loosen. The fastening nut on the handwheel should be tightened in time if it is found to be loose to avoid wearing the connection or losing the handwheel and nameplate.

If the handwheel is lost, it is not allowed to replace it with a live wrench, and it should be completed in time. The packing gland is not allowed to be skewed or without preload clearance. The ruler on the valve should be kept intact, accurate, and clear.

The seals, caps, pneumatic accessories, etc. of the valve should be complete and intact. If it is equipped with electric or pneumatic drive device, it should be maintained and maintained in strict accordance with the corresponding operation manual.

Daily valve maintenance.

1. The valve should be stored in a dry and ventilated room, and both ends of the passage must be blocked.

2. Valves stored for a long time should be checked regularly, dirt should be removed, and anti-rust oil should be coated on the processing surface.

3. After installation, regular inspections should be carried out, and the main inspection items are:

1) Sealing surface wear.

2) Trapezoidal thread wear of the stem and stem nut.

3) Whether the filler is outdated and invalid, if it is damaged, it should be replaced in time.

4) After the valve is overhauled and assembled, the sealing performance test should be carried out.

The inlet and outlet of the valve should be sealed with wax paper or plastic sheet to prevent dirty things from entering. The processing surface of the valve that can rust in the atmosphere should be coated with anti-rust oil to protect it. Outdoor valves must be covered with rainproof and dustproof items such as linoleum or tarpaulin.

The warehouse where the valves are stored should be kept clean and dry. For valves that are not used in the short term, asbestos packing should be taken out to avoid electrochemical corrosion and damage to the valve stem. The valve that has just entered the warehouse should be inspected, and if rainwater or dirt is entered during transportation, it should be wiped clean and then stored.

Daily maintenance of the valve.

1. Attention should be paid to the storage environment of the valve, which should be stored in a dry and ventilated room, and both ends of the passage should be blocked.

2. The valve should be checked regularly, and the dirt on it should be removed, and the anti-rust oil should be applied on its surface.

3. After installation and application, the valve should be regularly overhauled to ensure its normal operation.

4. Check whether the sealing surface of the valve is worn, and repair or replace it according to the situation.

5. Check the trapezoidal thread wear of the valve stem and valve stem nut, whether the packing is outdated and invalid, etc., and replace it as necessary.

6. The sealing performance of the valve should be tested to ensure its performance.

7. The valve in operation should be in good condition, the bolts on the flange and bracket are complete, the thread is not damaged, and there is no loosening phenomenon.

8. If the handwheel is lost, it should be completed in time, and cannot be replaced by a live wrench.

9. The packing gland is not allowed to be skewed or there is no preload clearance.

10. If the valve is used in a harsh environment and is susceptible to contamination by rain, snow, dust, wind and sand, a protective cover should be installed for the valve stem.

11. The ruler on the valve should be kept complete, accurate and clear, and the lead seal and cap of the valve.

12. The insulation jacket should be free of depressions and cracks.

13. Avoid knocking on the valve in operation, or supporting heavy objects.

1. Long-term storage of valves, should be regularly inspected, exposed processing surfaces must be kept clean, remove dirt, storage ball valves should be blocked at both ends and in an open state, gate valves, globe valves, check valves, both ends of the channel should be blocked and in a closed state, neatly stored in a ventilated and dry place indoors, it is strictly forbidden to stack or open storage.

2. Before installation, it is necessary to carefully check whether the pressure and diameter of the valve mark meet the requirements of use, eliminate the defects caused by the transportation process, and eliminate the dirt of the valve.

3. During installation, the valve can be directly installed on the pipeline according to the connection method. Under normal circumstances, it can be installed in any position of the pipeline, but it needs to be easy to operate and repair, pay attention to the flow direction of the shut-off valve medium should be the flow from the bottom of the longitudinal valve disc to the top, and the lifting check valve can only be installed horizontally.

4. When ball valves, globe valves and gate valves are used, they are only fully open or fully closed, and are not allowed to adjust the flow rate, so as to avoid erosion of the sealing surface and accelerate wear. There is an inverted sealing device in the gate valve and the upper threaded globe valve, and the handwheel is rotated to the uppermost position to tighten it to prevent the medium from leaking from the packing.

5. When opening and closing ball valves, globe valves and gate valves, hand wheels should be used, and no levers or other tools should be used to avoid damaging the valves. The handwheel rotates clockwise to close, and vice versa.

6. The bolts of the packing gland should be tightened evenly and should not be pressed into a crooked state, so as not to hinder the movement of the valve stem or cause leakage.

7. During the use of the valve, it should be kept clean frequently, and the transmission thread must be lubricated regularly.

The purpose of using valves in water treatment is to improve water quality and achieve certain water quality standards. Physical water treatment, chemical water treatment, biological water treatment, etc. are all based on different treatment methods. There are two types of valves according to different treatment objects or purposes:

The water supply department disturbs the friends and wastewater treatment. Water supply treatment includes domestic drinking water treatment and industrial water treatment.

When overhauling valves, it is required to be carried out in a clean environment. Start by cleaning the outer surface of the valve. Inspect and record any cosmetic damage.

Then disassemble the valve and clean it with kerosene (do not clean it with gasoline to avoid disaster), check the damage to the other parts, and make a record.

n Perform a strength test on the valve body and bonnet. If it is a high-pressure valve, non-destructive testing should be carried out, such as ultrasonic flaw detection and X-ray flaw detection.

n The sealing ring can be inspected with red dan powder to check the fit of the valve seat and gate plate (valve office). Check whether the stem is bent, whether it is corroded, and how the threads are worn. Check the degree of wear of the stem nut.

n Handle the problems that are checked. Defects in the repair welding of the valve body. Hardfacing or updating seals. Straighten or replace the stem. repair of all other parts that should be repaired; It cannot be replaced.

n Reassemble the valve. When assembling, the gasket and packing should be replaced.

n Strength test and tightness test.

1. The valve should be stored in a dry and ventilated room, and both ends of the passage must be blocked. Hongfeng valves stored for a long time should be checked regularly, the dirt should be removed, and the processing surface should be coated with anti-rust oil. After installation, regular inspections should be carried out, and the main inspection items are:

Seal face wear. Trapezoidal thread wear on the stem and stem nut. Whether the filler is outdated and invalid, if it is damaged, it should be replaced in time.

After Hongfeng valve overhaul and assembly, the sealing performance test should be carried out.

On the one hand, the amount of grease injection is small, the grease injection is insufficient, and the sealing surface accelerates wear due to the lack of lubricant. On the other hand, excessive grease injection causes waste. The reason is that there is no precise calculation of the sealing capacity of different valves according to the type of valve type.

The sealing capacity can be calculated according to the size and type of valve, and then the appropriate amount of grease can be injected reasonably.

3.When filling the valve, the pressure problem is often ignored. During the grease injection operation, the grease injection pressure changes regularly in peaks and valleys.

The pressure is too low, the seal leakage or failure pressure is too high, the grease injection port is blocked, the grease in the seal is hardened, or the sealing ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease mostly flows into the bottom of the valve cavity, which generally occurs in small gate valves. If the grease injection pressure is too high, on the one hand, check the grease injection nozzle, and replace it if the grease hole is blocked; On the other hand, grease hardening involves the use of cleaning fluids to repeatedly soften the failed sealing grease and inject new grease to replace it.

In addition, the sealing type and sealing material also affect the grease pressure, different sealing forms have different grease pressure, and the grease pressure of hard seal is generally higher than that of soft seal.