Eight valve common faults and treatment methods ship engine room valve supplier

Eight valve common faults and treatment methods ship engine room valve supplier

1. Leakage of valve body:
The reason:
1. The valve body has trachoma or crack;
2. Valve body repair welding tensile crack
Processing:
1. The suspected crack is polished, etched with 4% nitric acid solution, such as cracks can be shown;
2. Excavate and mend the crack.
Two, valve stem and its matching screw thread damage or stem head broken, valve stem bending:
The reason:
1. Improper operation, switch force is too large, limit device failure, over torque protection does not work. ;
2. Thread fit is too loose or too tight;
3. Too many operation times and too long service life
Processing:
1. Improve the operation and do not exert too much force; Check the limit device, check the torque protection device;
2. Select appropriate materials and meet the assembly tolerance requirements;
3. Replace spare parts
Three, valve cover joint surface leakage: Cause:
1. Bolt tightening force is not enough or tight deviation;
2. The gasket does not meet the requirements or is damaged;
3. Defective bonding surface
Processing:
1. Tighten the bolt or make the flange clearance of the door cover consistent;
2. Replace the gasket;
3. Disassemble and repair the sealing surface of the door cover
Four, valve leakage:
The reason:
1. Loose closure;
2. Bonding surface damage;
3. The gap between the valve spool and the valve stem is too large, resulting in the droop or poor contact of the valve spool;
4. The sealing material is poor or the spool is stuck.
Processing:
1. Improve the operation, restart or close;
2. The valve disintegrates, and the sealing surface of the valve core and seat is reground;
3. Adjust the gap between the spool and stem or replace the disc;
4. Valve disassembly, eliminate stuck;
5. Replace or surfacing the sealing ring
Five, the spool and valve stem detachment, resulting in switch failure:
The reason:
1. Improper repair;
2. The joint of spool and stem is corroded;
3. The switch force is too large, resulting in damage to the joint between the spool and the valve stem;
4. The spool stop gasket is loose and the connection part is worn
Processing:
1. Pay attention to inspection during maintenance;
2. Replace the door rod with corrosion resistant material;
3. The operation is not strong switch, or not fully open after continuing to open the valve;
4. Check and replace the damaged spare parts
Six, the valve core, seat crack:
The reason:
1. Poor surfacing quality of joint surface;
2. Treatment of large temperature difference between two sides of the valve:
Repair welding of cracks, heat treatment, polishing and grinding according to regulations.
Seven, the valve stem lift or switch does not move:
The reason:
1. When it is cold, it is closed too tightly after being heated, or it is too tight after being fully opened;
2. The packing is too tightly pressed;
3. Valve stem clearance is too small and bulge dead;
4. The valve stem is too tight with the screw, or the screw buckle is damaged;
5. Packing gland pressure deviation;
6. Door rod bending;
7 medium temperature is too high, poor lubrication, serious corrosion of valve stem
Processing:
1. After heating the valve body, try to open it slowly or close it slightly when it is fully opened and tight;
2. Loosen the packing gland slightly and try to open it;
3. Increase stem clearance appropriately;
4. Replace the valve stem and screw;
5. Readjust the packing gland bolt;
6. Straighten or replace the door rod;
7. The door rod is made of pure graphite powder as lubricant
Eight, packing leakage:
The reason:
1. Filler material is wrong;
2. The packing gland is not pressed tightly or is biased;
3. The method of packing is wrong;
4. Stem surface damage
Processing:
1. Correct choice of filler;
2. Check and adjust packing gland to prevent pressure deviation;
3. Install packing according to the correct method;
4. Repair or replace the valve stem provided by the technical department of Sanjing valve
Ship engine room valve supplier Introduction:
Shanghai Taichen Valve Co., Ltd. is a professional manufacturer of Marine valves. Our business scope covers all parts of the country and has a certain brand status in Shanghai. Our Marine valve products are manufactured in strict accordance with the national standard (GB), Marine industry standard (CB), Japanese standard (JIS), German standard (DIN), American Standard (ANSI). The Marine products we cover are butterfly valves, gate valves, ball valves, globe valves, check valves and Angle valves.
Material introduction of valve in engine room:
The valve is composed of two parts of the control mechanism and the valve body, the commonly used material of the valve has four kinds.
1, cast iron: cast iron valve temperature is about 125 degrees, and easy to rust. Suitable for sewage and other media.
2, cast steel: cast steel valve temperature can reach 425 degrees, the use of high temperature medium.
3, stainless steel: stainless steel valve has the role of corrosion resistance and high temperature resistance, suitable for a variety of complex conditions.
4, alloy steel: alloy steel valve material in addition to iron, carbon, but also added other alloy elements, used in a variety of high and low temperature environment.
Ship engine room valve use case picture:
Maintenance method of ship valve:
1. Marine valve maintenance method:
Marine valve maintenance can be divided into emergency maintenance, regular maintenance and predictive maintenance. Emergency maintenance is in the valve failure, can not meet the process operation requirements when the maintenance. Scheduled maintenance usually consists of routine maintenance and maintenance in conjunction with process suspension overhaul. Predictive maintenance is based on the analysis results of predictive maintenance, targeted maintenance of the relevant regulating valve parts. Emergency maintenance is the maintenance after the failure of the regulating valve, regular maintenance and predictive maintenance is the maintenance before the failure of the valve. Usually, the routine maintenance of Marine valves is carried out by instrument maintenance personnel, and the regular maintenance concurrent with overhaul is carried out by manufacturing technicians. The vulnerable parts of the valve are mainly: packing, sealing ring, gasket, piston sealing ring, diaphragm, soft seal seat, spool sealing liner. Every time maintenance will be replaced with new parts.
Two, Marine valve daily maintenance method:
1. Ask the process operator on duty about the operation of the valve.
2. Check the supply energy (air hydraulic oil or power supply) of Marine valves and related accessories.
3. Check the operation of the hydraulic oil system.
4. Check the static and dynamic sealing points of the valve for leakage.
5. Check whether the valve connection lines and connectors are loose or corroded.
6. Check whether the valve has abnormal sound and large vibration, and check the supply situation.
Check whether the action of the valve is flexible and whether it changes in time when the control signal changes
8. Listen for abnormal vibration or noise of the spool seat.
9. If a problem is found, contact the user for handling.
10. Make a record of the tour inspection and file it.