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Industrial Valve Repair & Maintenance System


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Industrial Valve Repair & Maintenance System

  1. 1. Re-top Valve Repair System (VRS) ReTop Valve Repair Co. Ltd. VALVE REPAIR SYSTEM(VRS) Independent IPR, Professional Customized Repair, Cost Saving Merits of Valve Repair & Restoration ◙ Practical ◙ Safe ◙ Effective ◙ Cost-saving 1. Practicality of valve restoration Out of serviced valves are mostly due to failure caused by sealing surface corrosion or tearing of inner parts, but once its metal physical stress relived, the strength of the valve body is stable, and the above is the premise and basis of valve repair and restoration, stress relived valves to be completely and systematically repaired and restored will not be affected by deformation, then improve the practicality of the valve. By using intact valve body to produce failure inner parts toCompany Introduction make it a brand new one. ReTop Valve Repair Co., Ltd. founded in 1994, which is the first professional 2. Safety for valve repair We will make best suitable repair programvalve repair and maintenance company. Since its establishment 15 years ago, we and select the most suitable welding rodsdevoted to professional solutions to on-line processing, maintenance and testing according to various production environment and transferring medium of the valve, to make themeasurements of metal sealing surface of the valves. Our products and restored valves in best forms to deal with thetechnologies had long been servicing Chinese electrical, oil and gas, severely production environments with prolonged life.petrochemical, chemical, steel, pharmacy and furnace industries and energysectors. From the very beginning, the company is setting up by numbers of 3. High efficiency of valve repair Our Patented VRS valve repair system isprofessional valve engineers and senior technicians of China valve base-ZIGONG. developed on the basis of mechanical principleBy 15 years research and repair services experience, now the company had been of dynamic balance, which unique function is milling and grinding, especially on stainless steelexpanded to R&D, design, repair of specialized industrial valves, and to valve and cemented carbide materials, that general typerepair and restoration machineries, we have one professional and well-trained machine tools cannot replaced. It can milling and grinding the bead welding valve body sealingvalve inspection and repair experts and onsite service man. surfaces and damper sealing surface. Besides, if Be worth mentioning, our independent developed & IPR VRS [Patent No. the VRS is to be used together with our developed special tools and VRS maintenance00223289.9] made breaking-through against other international brands that only machine, also can make the percent of hardrepair valves on basis of partly maintenance (e.g. selling stop valve seat grinder, sealing contact area of the sphere and valve body up to 99.5%after bead welding, and surfacestop valve milling machine by several models), it is combined repair and roughness can be up to 0.4µ sphere roundness m,maintenance of multi types, specification, Standard ball valve, check valve, block error can match requirements of specialized machines toolsvalve, safety valve, globe valve, butterfly valve, plug valve, control valve,spillover valve, diaphragm valve, drain valve, desulfurization valve etc with 4. Saving Cost for Valve Users As consumable products, users will pay bigcomprehensiveness, multifunction, it is simple in structure but practical, easy to money on replacing with new ones, take anassembly, together with special operational fittings and make repair and restoration example for large scale chemical companies, expenses on valve is around US$12.5 millionof various valves simpler and quicker. each year But the cost will be only 25-45% of Repaired and restored industrial valves can be up to standard, it is not only the buying costing if adopts valve repair, which will save cost on production and operations.solved leakage of pipeline valves and higher costs by replacing with new ones, butalso will increase the life cycle and safety of the valves by saving big cost forvalve users. ----------------------------------------------------------------------------------------------------------------------------- -------------------------------- The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ ExperienceVRS ----------------------------------------------------------------------------------------------------------------------------- -------------------------------- is applicable for valves with working pressure from 0.10MPa to 32Mpa,and nominal diameter from 10mm to 1200mm, testing and inspections after with be strictly accordingly to GB, ISO, ANSI/API/MSS,DIN,BS, NF,JIS
  2. 2. Valve Repair System (VRS) Concept Valve Repair System that using machine tools, grinding machine, milling machine and self-developed patented machinery [PatentNo.00223289.9], universal clamp fittings, pressure testing & inspection devices etc, realize that from bead welding of metal sealingsurface of used valves, precision finishing of new sealing surface, designing for soft sealing surface, manufacturing of valve components,adjusting of irregular geometric dimensions of the valves and repair failures caused by various factors to valve assembling, pressuretesting and inspection, painting & delivery, feedback, follow-up service. And the machine tools combination and interactive technicalprocess flows, and the maintenance procedures together consist of the Valve Repair System (VRS). Another highlighted feature of VRS is that it can realize valve repair and maintenance completely according to standards like GB,DIN, ISO, API, and ANSI. One fits all is the unique character of VRS. The unique and patented repair machines and repair clamp fittings are the core part of the system. By combination and assemblingoperations, VRS can finish quality maintenance and replace of sealing surface of various valves sized from DN50mm to DN800mm, forrepair and maintenance of higher sizes from DN1000mm to DN1200mm valves, also can be realized by using bigger sized VRM toolsand special fittings. 2The VR machine tools used in the system are all of general types, each scaled VRS is developed on the basis of mechanical principle of dynamic balance,company will equipped, then there is no concern for compatibility to users which unique function is milling and grinding, especially on stainless steel andrepairing supporting machines and tools. cemented carbide materials, that general type machine tools cannot replaced. ItValve repair and maintenance by single lathe have greatly limitation, as the size can mill and grind the bead welding valve body sealing surfaces and damperof valves to be repaired is limited by the fixing turning radius (R) of the machine sealing surface. Besides, if the VRS is to be used together with our developedtool and fitting’s dimension, e.g. C620 lathe can only finish repair of brake valve special tools and VRS maintenance machine, also can make the percent of hardof DN65mm and below and stop valve of DN80mm and below sealing contact area of the sphere and valve body up to 99.5%after beadThe universal clamping fittings is used together with lathes to repair stop valves welding, and surface roughness can be up to 0.4µm, sphere roundness error canbelow DN80mm, brake valve below DN65mm and ball valves, safety valves, match requirements of specialized machines tools.drain valves, plunger valves, ammonia valves, desulfurization valves etc medium Matching with Magnetic Chuck, it can also used for milling, processing andand small sized valves that below DN200mm. It also can be used for restore rotary metal sealing rings sized 500mm and below, e.g. that used onmanufacturing of parts that used for valve repairing and maintenance. compressor, industrial pumps.To measure if the VRS is systematically repairing or not, you can refer to the VRM is developed to repair big diameter valves, especially to repair bigger sizedfollowing two standards: wedged gate valves, like high and medium pressured oil pipelines, power1. To see if it can realize repair of wedged gate valve by replacing sealing stations gate valves etc. that with DN800mm and below. The VRM is muchsurface. As there is an gradient ratio between the valve sealing surface and easier and quicker to repair big sized check valves, ball valve seats, butterflydamper sealing surface, it is much difficult for manufacture or maintenance. valve seats and other type valves.Once repair for single damper gate valve is no problem, surely can complete Generally for gate valves users, they can not restore the gate valves by lackingother types valves; capabilities:2. Repair of valves of same type and specifications but different 1. Lathes without special fitting and clamps, plus no repair experiences;manufacturers, 2. For DN200mm and above sized gate valves will usually use vertical latheAlthough each manufacture uses fixed production fittings and comply with same which is not easily affordable.standards, the clamping fittings, type of designing, operation modes are differed VRM can be widely used with wide range variation and compatibility, like gateto each others, plus quality differences between production facilities, accuracy valves and stop valves from DN50m to DN800mm, and repair the valve seatclass, employee skill levels, then the physical dimension differs, which require and sealing surface continuously, and can change the dependence on turningthe valve repair system must have the ability of one fits all, i.e. no matter who is processing of vertical lathe.the manufacturer, or otherwise, it cannot be refer to a real valve repair system. VRS test and verified its repair functions and practical economic values. Now The reason that this VRS can finish valve maintenance and restoration had accomplished “no declination for valve repair requests; no failure oncequickly and effectively is mainly because of the self-developed patented Valve agreed to repair; quality is as new after required”.repair machines (VRM) and universal combination & assembly fittings, which isthe core part of the VRS, just as the main shaft of transmission machines. ----------------------------------------------------------------------------------------------------------------------------- ------------------------------ The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience ----------------------------------------------------------------------------------------------------------------------------- ------------------------------
  3. 3. Valve Failure Performance Valve leakage resulted in lose control of fluid flow and pressure, and then replaced with new ones. Valve leakage is the dominant symbol of valve failure. A leakage is not only refer to loss of sealing performance of the sealing surface, but also including aging, loosen of valve cover fillings and leakage by extensive clearance of valve handles. Valve leakage (internal leakage, external leakage)1. External leakage: leakage by air hole, pitting corrosion;2. Internal leakage: pertusions, fractures, crackles between the inner fitted damper, valve clack, sphere and soft sealing parts thencannot make conforming sealing.For external leakage can be noticed immediately, while internal leakage must monitored by instruments or altering devices. Valve Damage: It refers to a more widely range, like the following: 31. Tore failure of valve handle threads and nuts;2. Corrosion and thinner of lower parts of submerged valve handles;3. Deformation and broken of upper parts;4. Valve seat and sealing surface axial shifting;5. Corrosion and tore of universal stubs of valve clacks make the valve handle lost balance function;6. Mechanical damage between sealing surface of valve seat and sealing surface;7. Corrosion of T part of damper that make it smaller, and beyond normal working range to function;8. Loss of roundness of the sphere of ball valve, make the switch lose control and etch.Any case above will make the valve lost its function on the production equipments, pipeline systems. Valve Materials Learn the main composing material of the valves, to furnish theatrically foundation for valve repairing, ensure the safety of the valves. The main composing materials are directly related to the reliability and service life of the valves, also are one of the key factors that repair the valves with good quality. As guidance to specialized valve repairing, it has to have a good command of main materials of valves and applicable standards (it refers to main materials of steel structure valves).1. By classification of applicable environments, steel valves are mainly classified into the following four types:1) Common carbon steel WCB, WCC, e.g. valve that working temperature t≤425℃;2) Common low temperature steel LCB, LC2, LC3, CF3M, e.g. valve that working temperature t≤-240℃;3) High temperature steel WC6, WC9, ZG15Cr1MoG;4) heat-resistance stainless steelZG0Cr19Ni11Ti, ZG1Cr18Ni9Ti, CF8, 321H, 304H etc, e.g. heat-resistance valves that workingtemperature t≤650℃.2. By classification of molding types. Generally, manufacturers will take casting types, e.g. commonly used stop valves, gate valves,butterfly valves, ball valves etc usually to produce molds by casting method. However, limited conditions cannot use casting types, onlyforged, weld forged, coil weld structures applicable. E.g. pressure-bearing PN32MPa Angle stop valve and some high pressure &temperature adopts forge structure as the mold, and also like big sized seaboard valve, reducing ball valves also using weld forged, oilweld structure.----------------------------------------------------------------------------------------------------------------------------- ------------------------------The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience----------------------------------------------------------------------------------------------------------------------------- ------------------------------
  4. 4. Repair program for wrong valve material information To have good command of valves working environments, contact medium, bearing temperature and damage causes etc, make careful preparations before repair starts, e.g. lathe, machine tools and clamps, plans and selection of valve material to be repaired, parts prefabrication and personnel arrangement etc.We will recognize the real materials of the valve, and to avoid selecting wrong materials for repair, so not as to delay therepair, processing and delivery cycles.E.g. Some valves showing with WCB, but of HT cast iron, so, must report to users with real valve requirements and specification tomake repairing and remind the user to reduce the valve’s application level. Also to any changing and artificially modifying thespecifications marked on the valve bodies, will be carefully inspected and make repair and maintenance according to realconditions and specification and give instructions to use with real safety level and working performance. 4We will verify the original sealing surface, material of other components, to facilitate the repair and maintenance withrelevant data.E.g. standard for high temperature & pressure valve for power plant is ASTM and JB/T, steel grade is WC6, WC9 chromemolybdenum steel and heat-resistant steel CF8, 321H, 304H. Application of this kind of valves is determined by electrical devicePi-Piv high temperature, and working pressure PNt≤PN35 MPa. In order to suit the high temperature, sealing surface of the valveseat, clack, damper have to hot treated, surface hardness (49-53HRC), anti-tearing, finish requirements all need to be up topermissible standard, and back seal of valve handle, cover need to be up to qualified standard. Repair and maintenance of thiskind of valve must strictly in accordance with valve manufacturing techniques and parameters, and fabricate duplicate partscarefully to ensure repair quality.We will give reasonable valve application instructions to valve usersAs some companies use the valve inappropriately by consideration of lower cost, mainly as the following:A. Change medium pressured valve into low pressured valve during installation on production equipments and pipelines;B. Valves not suitable for high temperatures used in high temperature environment, shortened the service life;C. Put the soft sealing valves in coarse flowing particle environments, accelerated the damage;D. Neglected chemical medium corrosion to the metal body and parts, lacking valve usage directions and applicability, put an lowanti-tear performance valve at an high corrosion medium location, then lead to quick pitting corrosion;E. Improper operations caused damage. Small sized valve (DN10-DN50mm) is in small dimension, low rigidity & strength, thensealing with valve seat is thin and small, handle also much thinner, the axes of sealing surface is liable to be damaged. Operatorsmay not knowing the valve is about to losing sealing effects, and switch the handle in rush and make it bended or broken, then thesealing parts severely damaged when the switch it tight.Problems mentioned above, we will start technical communications and discussion in a way of qualitytracking method, and will give our reasonable instructions on proper valve selection and protections regardsto users.----------------------------------------------------------------------------------------------------------------------------- ------------------------------The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience----------------------------------------------------------------------------------------------------------------------------- ------------------------------
  5. 5. Procedure for Valve Repair and Maintenance Ball valves, gate valves, regulating valves, stop valves, plug valves that wildly used power plant, nuclear power plant, oil & gas, chemical, refinery, paper making, pharmacy etc. as there are impurities in the medium or impurities with strong corrosion nature, and in high temperature, high pressure working environments are liable to cause drag mark, corrosion, leakage, deform etc on the sealing surface and valve seating, then lead to valves out of service. It is big loss for users. Our maintenance and restoration center have been well-equipped with professional valve inspection and repair equipment, and use international advanced independent IPR Valve Repair System (VRS), and self-developed universal clamp fittings, to repair and inspect various valves with different disassembling difficulties. Repaired valves will meet testing standards before delivery, and furthermore we will provide warranty like manufacturers, to cut buying cost and save objective valves application cost for 5 users.Repair and maintenance procedureDisassembling  Rust & Impurity cleaning  Select proper electrodes according to customer’s valvesworking environments and extend bead weld  turning mill for small parts  Milling and grindingoperations to critical parts by our patented universal repair machines  Replace parts  precisionprocessing  sealing surface inspection  assembly valve  30% higher than standard testing on valvebody strength and sealing surface  painting and surface finishing and beautifying  delivery tocustomer New Case of Valve Repair All the replaced failed valves would have experienced corrosion of various medium, washing of fluid under pressure, different temperature affecting, both valve body and inner parts will be affected or damaged to certain extent, then the functions of the valve will be decreased or even total failure. However, those replaced or discarded valves not being completely worthless and without value to be repaired or restored and back to service. If by using knowledge of metallic structure principle, dynamics, fluidonics, corrosion, welding, hot treatment principles, equipping with necessary repairing devices and set up experienced teams, higher technical expertise, higher level and higher quality used valves repairing can be achieved.◆ Repair of high temperature and high pressure valves:Valve that’s working temperature t≥ 650℃ is refer to as high temperature valves;Valve that’s working pressure≥ PN6.4MPa is refer to as high pressure valve.Those valves usually applied in power plants, refineries, chemical fertilizer plants, oil pipelines, steel-making and ethylenedevices. High temperature, which main materials is of WC6 and WC 9 cast iron, don’t have anti-sulfur-attack performance, sogenerally medium for those valves is water, steam and oil. Generally, those that made of heat-resistant stainless steel 321 and 321H are strictly comply with common standards and----------------------------------------------------------------------------------------------------------------------------- ------------------------------The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience----------------------------------------------------------------------------------------------------------------------------- ------------------------------
  6. 6. specifications, so the strength of valve body, plasticity, hardness and tenacity will completely up to common internationalstandards, also with higher performance of anti-corrosion, pressure shocking and high temperature, and prolonged lifecircle.However, inner parts are not as firm as its body, and sealing functions to be accomplished by combination of its components,and realize sealing function to flowing medium by composite force. But, there is clearance and comprehensive errorsbetween the inner parts to each other, e.g. damper T groove lower part of handle, handle connecting groove. Those partswould experience wearing, deformation, increased clearance in high temperature environments and medium corrosion,washing, and then result in axial shifting of sealing, crack or scratch of sealing surface, increased corrosion of damperguiding groove, deformation of damper, not perfect matching with valve seats then lead to internal leaking. Those kindly ofvalves only can be back to service after repaired. Valve repair case:August, 2002. One of the valves sends to us for repair from YIBIN power plant, i.e. Z960Y-P54-100V high temperature &pressure electric actuated gate valve, is the key valve of main steam device that with severely internal leaking. Checking by 6disassembled, found there are two cracks at the bottom of valve seat sealing surface that almost in same size, i.e. width1mm, depth 2mm, also another two cracks found at the bottom of flexible valve disc, a little smaller than that in valve seat,and the disc was also found raised up, but damaged parts is just aligned with the valve seat sealing surface. By analysis, thematerial for the body is W6 or W9 Chrome molybdenum steel that with comparatively stronger creep resisting, so as it isworking under high temperature, but only with one year. So, that is why the wall thickness of the body is thicker, and damageis not related to the materials. Matching of the damaged part between the seat sealing surface and valve discs showingtwo points:The surface is ZG20Cr5MoVor Satellites cemented Carbides, must be processed by quenching-back fire process, but it isprobably leading to minor flaws of lower hardness, and the surface is not so even; Valve clack is slightly up wrapped, and then we recognized it under standard materials, then affected the heat resistantability of the elasticity valve disc. So, it cannot assure the perfect contact of the valve seat sealing surface and the sealingsurface of the disc, then it cannot afford high temperature steam washing and high pressured shocking, the anti-wearingability against scratching, then lead to cracks on the valve sealing surface. Repair Policy: Renew the sealing surface materialsUsing high pressured heat resistant and anti corrosion welding electrode CHR507Mo to make bead welding for seat andsealing pairs, make the weld seam reach 5mm, width 8mm to facilitate mechanical processing. Valve plate sealing surfaceusing Stellite alloy bead welding, and height reaching 4mm, weld seam 20mm. Soften the rear valve plate for processing bysealing surface lathe, valve seat using VRM patented repair machines processing sealing surface, and adopts highfrequency quenching techniques for stable hot treatment, hardness is 53HRC, quenching depth is 2mm, then using VRM forgrinding eventually, to make the surface roughness reach 0.4µm, axial contact 99.5%. By taking testing, it is totally complywith national standards, by tacking the allocation status, it was in service for 3years, and performing excellently.◆ Repair of big size gate valveNovember, 2002. Three Z41H-PN2.5MPa valves from water supply system of SiChuan JiuDa Group Vacuum SaltProduction Equipments, which is of DN 500mm, send to us for repair due to its big leaking quantity. (Taking one for example)After dissembled, making inspection and found that the inlet, valve disc and sealing surface get washing corrosion, body iswith an area of 120mm² depth 20mm, valve plate is with an area of 300mm² depth 22m, sealing surface is totally corrosion. , ,Valve body and plate is of A216 (WCB), which is with lower welding performance and liable to cause welding beam cracksdue to hard quenching inclination. Valve sealing surface and disc sealing surface is of A182-77a-F6a, martens tic stainless----------------------------------------------------------------------------------------------------------------------------- ------------------------------The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience----------------------------------------------------------------------------------------------------------------------------- ------------------------------
  7. 7. steel, liable to produce hard and brittle marten site, and result in welding seam and heat affected zone hardened and brittle,it is of low welding performance. Those valves is thick and with strong rigidity which liable to cause cracks, and have strictlyrequirements on overlaying welding. Repair policy:By using comprehensively performance weld electrode CHR507Mo, which is with higher anti-chloridion to make beadwelding for sealing surface. Before overlaying welding, firstly processed the surface pit, taper angle etc flaws, then make itto smooth. Due to poor welding performance of the valve body and valve plates basements, so must add one interimbetween the basement and bead welding so as to reduce or avoid liabilities to cracks, and also the mechanical performanceof the weld seam can be fulfilled. First using the good plasticity and tenacity A302 stainless welding electrode for interimwelding, then filling with heat resistant J507 low hydrogen type welding rods, make the strength of welding seam same withthe basement. During the bead welding, make the pits even that of overlaying welding, then start bead welding from thebottom of bevel ends, and spread out spirally, and using short arc and arc breaking welding method, make the welding seamwidth 4mm, strictly controlled according to welding standard, and avoid stress concentration. Adopt same bead weldingmethods when making cosmetic welding, the height is equal to the surface. Although the damaged valve body, sealing surface of the valve clacks removed, but also bead welding according to its 7original radin, start from R, by using short arc and arc breaking welding method, and welding seam widened by 6mm, andheight of bead welding is higher 3mm so as to facilitate mechanical processing. Valve plates sealing surface processed byspecial fitting on lathe, valve sealing surface is using VRM for special processing. And then assembly the valves for strengthand sealing test, it complied with national standard, and customer was satisfied. Part of customers list CNGC China North Chemical Industries Group, Sichuan LuTianHua Group (000912.SZ),Yunnan Large Chemical Co. YunTianHua Group、Sichuan Natural Gas Chemical Group 、SiChuan HeBang Corp 、Leshan Shengfeng Chemical Co., etc; Sichuan Yongfeng Paper Industry Joint Stock Co. Ltd, Paper-making Sichuan Fuhua Paper Industry Co., etc; Beverage Wuliangye Group Co., Ltd. (000858.SZ), etc.; Power plants Neijiang Thermal Power Plan, etc; Sichuan North Chemical Industries Corp, Guangyu Chemical Joint Stock Co. Ltd, Nanchong Feilong Chemical Fertilizer Ammonia Plant, YongAn Ammonia Co. Ltd., etc. Pharmacy China Taiji Group (600129.SH), etc.Since its establishment 15 years ago, we had repaired different types, materials, and standards, DN10mm-DN1000mm, PN0.1MPa-32PNMPa valves total up to tens of thousands and gained plenty experience. The two cases above are mainly analyzed onthe basis of materials and damaged reasons, valve repair and material selection and techniques adopted, to reflect one view ofour valve repair system.Technically speaking, single plate wedged valve is the most difficult to repair, once accomplished the repair of this type, and theother types will be easy to be repaired. So, it is the critical technical parameter to evaluate our repair quality, and proved that arefull of experience and technical strength, shown our VRS strength.We had signed Witeam Commercial (Int’l) Limited as the official exclusive distributor for the oversea market of the Valverepair system (VRM).----------------------------------------------------------------------------------------------------------------------------- ------------------------------The First and Best Valve Repair System Proprietary Intellectual Property Rights 16 Years’ Experience----------------------------------------------------------------------------------------------------------------------------- ------------------------------