Spring safety valve overhaul procedures

3.1 Spring-loaded safety valve overview and parameters: 3.1.1 Spring-loaded safety valve Overview: "Safety valve" is the final safety protection device between the controlled boiler and catastrophic explosiveness, when the pressure is too high, the valve inlet pressure rises, Until the force exerted by the system pressure on the valve flap is equal to the force generated by the spring. This will cause the relief valve to act or open suddenly, releasing excess steam until the system pressure drops to the required level. 3.1.2 The main performance parameters of spring-loaded safety valve Taipower SG-2028 / 17.5-M907 boiler installed spring-loaded safety valve 18, including: drums 6, Model: Maxiflow 1749WB type, inside / outside diameter: 71.20 / 71.20mm Design Opening pressure: right 1: 19.79Mpa, right 2: 20.19Mpa, right 3: 20.38Mpa, left 1: 19.99Mpa, left 2: 20.19Mpa, left 3: 20.38Mpa. Superheater outlet 2, Model: Maxiflow 1740WD type, inside / outside diameter: 71.20 / 71.20mm Design open pressure: right: 18.28Mpa, left: 18.31Mpa. Reheater inlet 6, Model: Maxiflow 1705RRWB type, inside / outside diameter: 141.75 / 141.75mm Design open pressure: the right 1: 4.430Mpa, the right 2: 4.340Mpa, the right 3: 4.300Mpa, the left 1: 4.430Mpa, Left 2: 4.340Mpa, left 3: 4.300Mpa. Reheater outlet 2, Model: Maxiflow 1785WD type, inside / outside diameter: 132.72 / 132.72mm Design open pressure: right: 1.020, left: 4.020Mpa. Body blowing ash 1, model: 1912-00MT inside / outside diameter: 63.00 / 63.00 Design open pressure: 4.0Mpa. Empty pre-blowing a, model: 1922-00KT inside / outside diameter: 45.25 / 45.25 Design open pressure: 4.0Mpa. Another auxiliary steam box on the right side 1, Model: A48Y-16C inside / outside diameter: 124.85 / 124.85 mm Design opening pressure: 1.25Mpa. Auxiliary box on the left side of a, Model: A48Y-16C inside / outside diameter: 124.85 / 124.85 Design open pressure: 1.25Mpa. 3.2 Spring-loaded safety valve repair steps, process methods and quality standards 3.2.1 Spring-loaded safety valve preparation 3.2.1.1 confirmed that the valve has been effectively isolated, work-related risk pre-control measures have been implemented. Safety technology has been completed. 3.2.1.2 Tools, measuring tools, spare parts have been prepared. 3.2.1.3 Check the valve body outside the valve body surface should be no blisters, no cracks, no heavy skin, bolts and parts intact. 3.2.1.4 on the valve to be removed at the bolt loose agent lubricated. 3.2.2 spring-type safety door inspection steps, process methods 3.2.2.1 safety door disintegration. 3.2.2.1.1 Remove the joystick pin, joystick, lifting gear; Remove the positioning nut positioning pin and reset the nut. 3.2.2.1.2 Measure the distance between the upper end face of the compression screw and the top of the stem with a depth gauge and make a note of it 3.2.2.1.3 Loosen the compression screw lock nut and turn it counterclockwise with a special wrench until the compression screw and spring The upper washer is released. 3.2.2.1.4 Use a special wrench to evenly remove the two top yoke nut. Lift the yoke off the valve stem, making the original positioning mark on the top of the spring Remove the standoff assembly and top spring washer and spring bottom spring washer. Remove the cotter pin from the overlapping collar and stem assembly. 3.2.2.1.5 Make a mark on the upper ring of the overlapped collar and the notch of the stem pin bore and then turn the overlapping collar counterclockwise until the lowest of the four rings on the ring is flush with the lifting washer. 3.2.2.1.6 Carefully count the number of notches passing through the front of the stem opening pin hole. 3.2.2.1.7 Positioning markings on the cover and vent, then remove the cover studs and remove the cover from the studs. The valve stem together with the valve flap, valve ring ring assembly removed from the valve. Remove the valve disc and disc clamper from the stem, measure the distance from the top of the guide to the seat and measure the distance from the top of the guide to the bottom of the upper adjustment ring, record and remove the upper retainer ring , Proposed guide. 3.2.2.1.8 Remove the lifting ring and guide block assembly from the base, mark the radial position of the upper adjustment ring notch with respect to the guide with the marker, and loosen the lower adjustment ring pin until the notch of the pin and ring is slightly Separated. Then place a flat plate on the top of the sleeve seat, make a mark on the notch of the lower adjusting ring at the pin of the lower adjusting ring, revolve the adjusting ring anticlockwise until the contact of the adjusting ring with the flat plate and record the number After adjusting the number of notches in the ring pin, lower the lower adjusting ring from the seat sleeve and remove it from the valve body. (Note: do not turn the lower adjusting ring when adjusting the ring pin). 3.2.2.2 Safety valve inspection 3.2.2.2.1 The gland nut, bushing, up and down adjustment rod removed, check the threaded parts for damage, if there is damage should be trimmed with a file, with 1755 cleaning agent rust Wipe clean 3.2 .2.2.2 remove the upper and lower adjustment ring, thoroughly clean the threaded parts 3.2.2.2.3 Check the valve seat surface defects, check the wall wall erosion caused by wear thinning phenomenon 3.2.2.2.4 measuring the sealing surface weld metal Thickness and nozzle-shaped valve seat sealing surface of the mouth of the non-parallelism, such as excessive sealing surface should be corrected for grinding (welding metal thickness of not less than 4mm, sealing surface of the valve body non-parallelism shall not exceed 0.03mm ) 3.2.2.2.5 Check the sealing surface to the height of the main valve seat reference surface, such as less than 1.5mm should be processed on the main valve seat reference surface 3.2.2.3 disc valve assembly inspection 2.4.2.3.1 Visual inspection sealing surface damage and guidance Parts have rub, bite, adhesion, stuck traces, if any should be cleaned, and the guide sleeve and the outer flap clean 3.2.2.3.2 check the valve stem head contact with the existence of cracks and other defects, such as Should be replaced 3.2.2.3.3 Check the sealing surface wear 3.2.2.4 Stem Check 3.2.2.4.1 visually check the valve stem surface biting, adhesion, stuck traces, if any should be cleaned, trimmed, if serious should be replaced 3.2.2.4.2 Check the valve stem is not straightness, Exceed the standard should be amended, can not be amended should be replaced 3.2.2.4.3 check the wear and tear of the stem shall not be greater than 0.1mm, stem threaded connections intact, with a good nut, the top of the park arc without wear and tear, with a magnetic particle check valve stem The existence of cracks in the head and other defects, if any should be replaced. 3.2.2.5 Spring Inspection 3.2.2.5.1 Appearance inspection of spring surface rust removal should be smooth and harmless Cracks, scars, corrosion and other defects 3.2.2.5.2 Measuring spring free height should meet the requirements, the two ends parallel, and vertical 3.2.2.5.3 spring free to restore the free height 3.2.2.5.4 spring seat no cracks and other defects 3.2.2.5.5 spring and spring seat contact should be smooth, contact with good when the response Research and correction 3.2.2.5.6 The surface of the spring should be replaced by more than 50% of the total surface area. 3.2.2.6 Check whether the contact between the retaining ring and the lower spring seat is in contact with the landslide. When the distance between the retaining sleeve and the stem is free, Respond to research 3.2.2.7 visual inspection of the appearance and the valve stem is defective or not 3.2.2.8 safety door sealing surface grinding 3.2.2.8.1 grinding tool preparation 3.2.2.8.1.1 standard primary platform 3.2.2.8.1.2 grinding tire (HB <40 Cast Iron) and Handle 3.2.2.8.1.3 Scraper and File 3.2.2.8.1.4 Engine Oil, Red Dill, Acetone 3.2.2.8.1.5 Cotton, Oil Blanket 3.2.2.8.1.6 # 400, # 800, # 1200 Mill Paste 3.2.2.8.2 grinding tool made as shown below: 3.2.2.8.3 Thoroughly clean and polish the surface and around it. Apply # 400 (or equivalent) abrasive paste on the abrasive tire and apply a uniform and uniform pressure on the abrasive surface. Rotate the handle slowly in both positive and negative directions until the sealing surface is smooth , No pits and scratches 3.2.2.8.4 Respectively with # 800 and # 1200 abrasive paste fine grinding and polishing, each change grinding paste when the old abrasive must be cleaned with acetone, polished grinding, coated with a small amount Gently polish the abrasive paste until it is clear and then apply a small amount of abrasive paste on the felt to a piece of wood larger than the outside diameter of the seal face and press it several times over the seal face until the seal faces appear bright 3.2.2.8.5 Insert the hot valve Smear the tongue and back of the tongue into the abrasive paste and the body of the abrasive paste clean, the use of a platform and Hongdan pink check the sealing surface of the radial kiss and degree of kiss and degree of sealing surface must exceed 80% of the width of 3.2. 2.9 Safety Door Assembly 3.2.2.9.1 After wiping the inside of the valve body, the valve disc, the valve seat, etc. with cotton wool soaked in acetone, the valve disc should be lowered into the valve body. Never use cotton yarn or linen. 3.2.2.9.2 Installation Guide Set, pay attention to the position of the guide sleeve Must be the same as the position before disintegration, the inner wall of the guide sleeve and the outer wall of the valve flap evenly coated with a suitable lubricant, fastening screws should be tight 3.2.2.9.3 up and down adjustment After thorough overhaul, the thread coated with lubricant installed in 3.2.2.9.4 Install the cooler according to the position before disassembly and pay attention to the position of the steam exhaust pipe before disassembly. 3.2.2.9.5 Place the stroke control ring on the valve rod and measure the stroke of the valve to determine Valve position, the standard 12.5 + 1mm. 3.2.2.9.6 Confirmation of the stem of the horizontal pin into the back of the valve into the turn slot, a good spring and the spring seat, tight spring tightness bolts to demolition before measuring height, install the Xin spring to relax the screw 3.2.2.9 .7 Good spring cover and install the manual opening device 3.2.2.9.8 Clean the bolts, add gaskets, exhaust flanges exhaust exhaust elbow 3.2.3 Spring-loaded safety valve maintenance quality standards: 3.2.3.1 Safety door back loading. 3.2.3.1.1 Make sure the upper and lower adjustment rings are in the correct position. 3.2.3.1.2 Measure the height of the adjusting screw correctly (in this case, the spring is pressed against the spring cover). 3.2.3.1.3 The stem is not deformed by the bending moment. 3.2.2.1.4 spring surface crack-free, heavy skin, serious rust, beat no abnormal sound loud and clear. 3.2.2.2 Safety valve check 3.2.2.2.1 gland nut, bushing, the upper and lower adjustment rod removed, check the threaded parts without damage, if the damage should be used file trimming, rust cleaning with 1755 cleaning agent. 3.2.2.2.2 up and down adjustment ring, thread parts clean. 3.2.2.2.3 valve seat surface without defects, check the wall without wear and tear caused by wall thickness thinning phenomenon. 3.2.2.3 Inspection of the valve disc assembly 3.2.2.2.5 Check the height of the sealing surface to the main valve seat reference surface of not less than 1.5mm. 2.4.2.3.1 Visual inspection of sealing surface damage and guide parts without rubbing, bite, adhesion, stuck traces. 3.2.2.3.2 Check the valve stem head contact surface defects such as no cracks. 3.2.2.4 Stem check 3.2.2.4.1 Visual inspection Stem surface is no bite, adhesion, stuck traces. 3.2.2.4.2 Check the stem of the non-straightness, exceeding the standard as follows: Stem curvature measurement method as shown below, the value of not more than 0.05mm: 3.2.2.4.3 Check the stem wear should not exceed 0.1mm, Stem connection threaded intact, with a good nut, the top of the park arc without wear and tear, check the valve stem with a magnetic particle defects such as cracks, if any should be replaced. 3.2.2.5 Spring inspection 3.2.2.5.1 Appearance inspection of spring surface rust removal, smooth and harmless cracks, scars, corrosion and other defects 3.2.2.5.2 Measuring spring free height should meet the requirements, the two ends parallel and perpendicular to Axis, vertical deviation of not more than 2mm 3.2.2.5.3 After the spring can restore free height compression 3.2.2.5.4 spring seat without cracks and other defects 3.2.2.5.5 spring and spring seat contact should be smooth, poor contact should be training Positive 3.2.2.5.6 The surface of the spring should be replaced by more than 50% of the total surface area. 3.2.2.6 Check the contact between the retaining ring and the lower spring seat. Park block should be free stroke with the stem. If the contact is not good, 3.2.2.8 Grinding of sealing surface of safety door 3.2.2.8.1 Thoroughly clean the surface and its surroundings, apply # 400 (or equivalent particle size) polishing paste to the grinding surface, and apply full and uniform pressure on the grinding surface repeatedly in the positive and negative directions Slowly rotate the handle until the sealing surface is flat without pits and scratches. 3.2.2.8.2 Respectively with # 800 and # 1200 abrasive paste fine grinding and polishing, grinding paste each change when the old abrasive must be cleaned with acetone, polishing grinding, a small amount of grinding paste coated with a light grinding until Bright, after the oil felt coated with a small amount of abrasive paste with a larger than the outer diameter of the sealing surface of the wood, pressure on the sealing surface rotation several times until the sealing surface appears bright 3.2.2.8.3 hot valve tongue back cavity leakage into the grinding Paste and the body of the abrasive paste clean, the use of a platform and Hongdan pink check the sealing surface of the radial kiss and degree of kiss and degree must exceed 80% of the width of the sealing surface 3.2.2.9 safety door assembly 3.2.2.9.1 The valve body, valve, valve seat, etc. with cotton wool soaked in acetone, the valve flap down to the body, remember never use cotton yarn or linen cloth 3.2.2.9.2 installation guide sleeve, pay attention to the position of the guide sleeve Must be the same as the position before disintegration, the inner wall of the guide sleeve and the outer wall of the valve flap evenly coated with a suitable lubricant, fastening screws should be tight 3.2.2.9.3 up and down adjustment After thorough overhaul, the thread coated with lubricant installed in 3.2.2.9.4 according to the previous position before disintegration Cooler, exhaust pipe should be noted that in the mounted position before the disintegration of the travel control 3.2.2.9.5 collar on the stem, to determine the stroke measuring valve flap flap position. 3.2.2.9.6 Confirm that the cross pin of the stem is placed in the revolving slot at the back of the valve flap and the upper spring and the upper spring seat are tightly fastened by the spring to measure the height before demolition 3.2.2.9.7 Good spring cover And install the manual opening device 3.2.2.9.8 clean the bolts, add gaskets, exhaust flanges exhaust exhaust elbow 3.3 Safety, health and environmental requirements: 3.3.1 Safety 3.3.1.1 First check the safety measures and Workflows meet the requirements of safety regulations before starting work. 3.3.1.2 Before loosening the valve bolt, check if there is no pressure in the pipe. Check if the trap door is open and the water has been released. 3.3.1.3 In the overhaul process, the hydrophobic door must be kept open until the valve leaks out of the wound. 3.3.1.4 When loosening the bolt, care shall be taken to prevent it from being sprayed by steam or hot water which may accumulate. 3.3.1.5 After the valve is disassembled, arrange the tools and parts removed, and protect the disassembled valve to prevent foreign matter from falling in. 3.3.1.6 When working on soda pipe for a long time, the pipe segment with tail shall be reliably cut off by the block pipe with tail in the overhaul section. 3.3.1.7 In the installation, the return pipe flange or valve, not allowed to use your fingers into the hole touch. To prevent finger injury. 3.3.1.8 work at heights, wear safety helmets, wear protective clothing and work shoes, and take good care of the materials, spare parts, etc. should be placed in a solid and reliable place. 3.3.1.9 emergency elimination should be done to prevent the high temperature valve pipe burns safety measures, such as anti-hot work clothes, gloves, work shoes and so on. 3.3.1.10 Use of electric tools to pay attention to leakage, the risk of electric shock, the use of electric grinder, the risk of iron eye damage; check the power tools to prevent leakage, the use of angle grinders and other electric tools to wear protective eyes. 3.3.1.11 Replacing the valve During welding, prevent electric sparks from splashing in the cable tray causing a fire hazard. 3.3.2 Health 3.3.2.1 In the work environment under the conditions of high temperature work, to do a good job in the prevention of stroke. 3.3.2.2 on the workplace near the high-temperature objects, to be well protected from contact with workers on high-temperature objects. 3.3.2.3 Do not work too hard at work to prevent waist sprain. 3.3.2.4 Use dust masks or qualified masks when removing insulation from pipes or valves. 3.3.2.5 staff entering the pipeline or underground should rotate their work and rest. 3.3.3 Environment 3.3.3.1 Remove the parts to be neatly arranged. 3.3.3.2 valve tight test kerosene used properly placed, not directly into the garbage dump or sewer. 3.3.3.3 Conducting pipe or valve painting work, to be done to prevent paint fall underground or flow to other equipment. 3.3.3.4 After the work is over, clean the work site and ensure the cleanliness of the work place. 3.3.3.5 work is completed, clean up the site, classified into garbage dumps. 3.4 after-service test items and standards 3.4.1 equipment put into operation before the water pressure with the furnace. No leakage of hydrophobic pipe, no media after the closure of the phenomenon of drip, indicating that the valve sealing surface qualified. 3.5 Maintenance category and overhaul cycle 3.5.1 Maintenance once a year, the size of the random group equipment repair 3.6 Spring-type safety valve maintenance 3.6.1 Maintenance in routine operation 3.6.1.1 Inspection point content 3.6.1.1.1 Visual boiler valve seal Whether the surface? B leakage, the components are damaged, visual ear to hear the implementation of institutions without leakage, the implementation of power with or without leakage. 3.6.1.2 Inspection point standard 3.6.1.2.1 Visual boiler valve sealing surface without? B leakage, parts without damage. 3.7. Regular maintenance project in operation, cycle and standard regular maintenance project