Used Romer Automatic Sprinkling Chambers With Dryin for sale (21,756)

Year of construction: 2020, condition: new, Description Automatic sprinkling chamber is a solution that allows you to reduce costs, improve quality and increase the efficiency of the surface preparation process. The automatic sprinkling chamber is equipped with a set of spray pumps, it was designed so that as little liquid as possible after the process migrates to subsequent processes, thus saving money and improving the quality of washing. This is very important, because apparent savings in systems made without the use of these solutions can generate in the future much higher costs associated with chemistry and waste disposal which will simply be more. Attention should also be paid to problems with maintaining the required bath parameters. Research and development work allowed us to develop a sprinkling chamber with the function of drying details (option) with hot air blown by a set of fans after the washing process. The sprinkling chamber is equipped with an advanced system for creating your own macro programs, which can consist of 10 steps each, depending on the number of tanks, processes can be repeated, their order can be changed, etc. Each tank has its own unique icon and name, enabling the operator to work intuitively. Optionally, the tanks can be equipped with bath replenishment systems, which can be performed e.g. between processes or at the end of the cycle. • Control installed on the swivel arm for better access • PLC microprocessor control • 7 "touch operator panel • Very large number of nozzles, compared to other solutions • (Option) The possibility of drying details after the washing process • The ability to create your own advanced programs • Advanced damper system made of acid-resistant sheet metal, double protected by limit switches Klodpfefzq Stox Aqgjt • Tight closing and full flap opening control system • To minimize fluid mixing, separate pipelines, nozzles, tanks for each treatment • Intelligent control - in the event of a power cut / sudden shutdown, no mixing of liquids possible • Fully automatic operation/ Prices are given in the catalog

Year of construction: 2020, condition: new, Description Klsdpjflmdbjfx Aqgot Automatic sprinkling chamber is a solution that allows you to reduce costs, improve quality and increase the efficiency of the surface preparation process. The automatic sprinkling chamber is equipped with a set of spray pumps, it was designed so that as little liquid as possible after the process migrates to subsequent processes, thus saving money and improving the quality of washing. This is very important, because apparent savings in systems made without the use of these solutions can generate in the future much higher costs associated with chemistry and waste disposal which will simply be more. Attention should also be paid to problems with maintaining the required bath parameters. Research and development work allowed us to develop a sprinkling chamber with the function of drying details (option) with hot air blown by a set of fans after the washing process. The sprinkling chamber is equipped with an advanced system for creating your own macro programs, which can consist of 10 steps each, depending on the number of tanks, processes can be repeated, their order can be changed, etc. Each tank has its own unique icon and name, enabling the operator to work intuitively. Optionally, the tanks can be equipped with bath replenishment systems, which can be performed e.g. between processes or at the end of the cycle. • Control installed on the swivel arm for better access • PLC microprocessor control • 7 "touch operator panel • Very large number of nozzles, compared to other solutions • (Option) The possibility of drying details after the washing process • The ability to create your own advanced programs • Advanced damper system made of acid-resistant sheet metal, double protected by limit switches • Tight closing and full flap opening control system • To minimize fluid mixing, separate pipelines, nozzles, tanks for each treatment • Intelligent control - in the event of a power cut / sudden shutdown, no mixing of liquids possible • Fully automatic operation/ Prices are given in the catalog

Year of construction: 2020, condition: new, Description Automatic sprinkling chamber is a solution that allows you to reduce costs, improve quality and increase the efficiency of the surface preparation process. The automatic sprinkling chamber is equipped with a set of spray pumps, it was designed so that as little liquid as possible after the process migrates to subsequent processes, thus saving money and improving the quality of washing. This is very important, because apparent savings in systems made without the use of these solutions can generate in the future much higher costs associated with chemistry and waste disposal which will simply be more. Attention should also be paid to problems with maintaining the required bath parameters. Research and development work allowed us to develop a sprinkling chamber with the function of drying details (option) with hot air blown by a set of fans after the washing process. The sprinkling chamber is equipped with an advanced system for creating your own macro programs, which can consist of 10 steps each, depending on the number of tanks, processes can be repeated, their order can be changed, etc. Each tank has its own unique icon and name, enabling the operator to work intuitively. Kedpefy T Szefx Aqgolt Optionally, the tanks can be equipped with bath replenishment systems, which can be performed e.g. between processes or at the end of the cycle. • Control installed on the swivel arm for better access • PLC microprocessor control • 7 "touch operator panel • Very large number of nozzles, compared to other solutions • (Option) The possibility of drying details after the washing process • The ability to create your own advanced programs • Advanced damper system made of acid-resistant sheet metal, double protected by limit switches • Tight closing and full flap opening control system • To minimize fluid mixing, separate pipelines, nozzles, tanks for each treatment • Intelligent control - in the event of a power cut / sudden shutdown, no mixing of liquids possible • Fully automatic operation/ Prices are given in the catalog

Condition: refurbished (used), Year of construction: 2015, Durst P10-200 with Corrugated Option, fully automatic Resolution: 10 pl - 1000 dpi Color: 6C + (optional White) Very low usage Speed up to 2025 m2/h Fully automatic loader (feeder) Fully automatic unloader (stacker) INK: Paper and board with very low odor Options: Corrugated Option with 2 rails for dropping down material Corrugated static bar for different material thicknesses Kljdoy Amckjpfx Aqgot Corrugated software to control media and thickness - Understatic bar and automatic media stop for crash prevention - Caldera Rip Software Demo video is from Durst Rho 750 (28 pl, 600 dpi)

Year of construction: 2020, condition: new, Use of one photocell Using one photocell in the space of workpiece allows you to measure the length of the workpiece and, consequently, gives you the opportunity to turn on the guns when the item is in range, and to switch off the gun immediately after the workpiece is finished. The photocell is included in the standard equipment.Identification of details using special tags. A plate with identification holes is placed over the suspension. Based on this, the PLC controller in conjunction with the photocell recognizes the painted detail, turns on and off the guns in a timely manner - thus braking the energy and powder coating. Vertical detection of the detail of the workpiece. The use of light gates with detectors horizontally allows the PLC to analyze the vertical shape of the workpiece. Application of light gates with multiple sensors horizontally and vertically. This solution allows precise measurement of the dimensions of the workpiece, which makes it possible also to manipulate the manipulators. Benefits of using gates and photocells The benefits of using photocells or light gates are primarily energy and powder savings. Eliminate painting of a zone in which there is no detail. With the use of light gates, precise control of the guns. Kljdpfx Aqsfy T Arogst Our lines can be optionally equipped with photocells, or light gates Using one photocell in the workpiece space allows you to measure the length of the workpiece and, consequently, gives you the ability to turn on guns when the item appears in their range, and turn off the gun immediately after the workpiece is finished.Identification of details using special tags. A plate with identification holes is placed over the suspension. Based on this, the PLC controller in conjunction with the photocell recognizes the painted detail, turns on and off the guns in a timely manner - thus saving the energy and powder.The use of light gates with detectors horizontally allows the PLC to analyze the vertical shape of the workpiece. The PLC counts the time in which the detail will appear in the gun space - allowing guns to be selectively switched on or off.Using of light gates with multiple sensors horizontally and vertically This solution allows precise measurement of the dimensions of the workpiece, which makes it possible also to adjusting the manipulators.The benefits of using photocells or light gates are primarily powder and energy savings Eliminate painting of a zone in which there is no detail With the use of light gates, precise control of the guns The PLC counts the time at which the detail should appear in the gun space - allowing guns to be selectively switched on or off.

Condition: new, Year of construction: 2025, functionality: fully functional, machine/vehicle number: KAP1, air demand: 16,000 m³/h, power: 36 kW (48.95 HP), suction capacity: 16,000 m³/h, Equipment: cabin, Dielectric automatic powder booth KAP1 Price: PLN 492,693.30 + VAT Electrical and energy data • Voltage: 400 V (3P + N + PE) • Power connection: 36.34 kW • Pneumatic connection: 1" • Air pressure: min. 6 bar • Air quality: oil < 0.1 mg/m³, water vapor < 1.3 g/m³ • Air consumption: 1710 Nl/min (operation) • Compressor: SC-30 • Air tank: 1800 L Painting parameters • Painting speed: 1933 mm/min Kljdpov Rpx Sjfx Aqgst • Part dimensions: 800 x 1800 mm • Hanger height: 500 mm • Coating thickness: 100 µM • Gun array: vertical Technical data and configuration • Design: dielectric plastic • Passage dimensions: 1000 x 2400 mm • Air flow: 12348–16000 m³/h • Powder center: ProfiCenter CP02 • Manipulators: 2 pcs. • Guns: 8 automatic, 2 manual (ProfiSpray) • Part detection: yes (height, width) • Systems: cyclone separator, ProfiControl, beam pulling • ATEX: zone 22, II 3D Platforms and cabin body • Platforms: entry, exit, stainless steel floor, anti-slip stairs • Housing: dielectric plastic, LED lighting, slots for manipulators Air knives and suction channel • Automatic floor cleaning • Suction channel with pneumatic flap Gun blow-off and control • Automatic blow-off guns • 10" touch panel, 50 programs, manipulator control, dust extractor, drive speed X-axis and part pulling system • Automatic gun setting • Part pulling: speed 570–2830 mm/min, 2 pullers The machine also includes: • ProfiSpray A applicator • PSS-1 controller • PM-1 guns • ProfiCenter CP-02 powder center • CK-D1400L cyclone dust extractor • MA1-180 manipulator and MX1-10 X-axis • OZ-12H dust extractor • ProfiControl 10" control • BP-H2000 W900 part measuring system

Condition: good (used), Year of construction: 2008, Built in: 2008 Size: max 320 x 320 mm; min 150 x 145 mm Cover size: max 660 x 320 mm; min 225 x 135 mm Book block thickness: max 65 mm Weight: 2,100 kg Cover thickness: 80-300 g/qm Pile height: max. 150 mm Speed: max 1,350 c/h Kledju R Hxgspfx Aqgjt Type of current: 400/50 V/Hz Overall dimensions: w x h x l 3.610 x 2.910 x 1.80 mm Equipment perfect binder: - 4 clamps - milling station with pressing roller - hotmelt spine gluing unit - hot melt side gluing unit - PUR gluing unit - Premelter for PUR gluing unit .

Year of construction: 2008, condition: used, Guzzetti tube mill 76-200mm with a lot of tools and automatic stacker can be perfect solution for your tube production business. This line will allow you to produce huge range of round and rectangular pipes in very easy and automatic way. Line is equipped with important machines to make manufacturing process maximum convenient and productive. You can purchase machine as is where is or we can offer to make repair. Also we can provide shipping and installation service. If you start business with us you will never regret! Make: Guzzetti (Italy) Year: 2008 Automatic stacker: MAIR / Italy Tube range: D76- D200 Material’s thickness is 2-6mm (incl and SS) PLC – Siemens and all inverters and servo drives Welding aggregate is Thermomachine / Italy This line is also equipped and with the following machines: – Double dec.machine – Strips ends manually welding machine – Horizontal accumulator – 10 stations forming machine Material thickness is adjusting not manually – it is done by el.motors depend of el.indicators e. Welding aggregate is Thermomachine / Italy f. Cooling system g. System for automatic control of tubes sections dimensions h. 4 calibration stations + 4 TH The TH are with mechanical movements depend of necessary calibration. i. Fly cut-off unit is with two geared motors : one for hot cut off and another for cold cut off j. Automatic stacker is MAIR . Max tubes length is 12m. Packets for round tubes are hexagonal or octagonal types and for square tubes square or rectangular depend of tube’s dimensions. Tools available with machine: – Round Tube Ø76,1 – 1 set Ø88,9 – 1 set Ø95 – 1 set Ø101,6 -1set Ø108-1set Ø114,3-1set Ø125 – 1 set Ø133-1set Ø150-1set Ø159-1set Ø188-1set – Rectangular tube 60×60 70×70 75×75 80×80 85×85 90×90 Kedpsi D D Efofx Aqgslt 100×100 105×105 120×129 125×125 150×150

Condition: used, Automatic cutting, brushing & washing, drying, made RSA Entry length: 12.000mm Exit length: 30 - 1.000 mm In packed condition – ready to be delivered. Entry length: 12.000mm Exit length: 30 - 1.000 mm Klodpfx Aqoymarleget Diameter: 12 - 80 mm

Condition: used, Automatic Bag Filling Line Bag weights from 5kg to 1000kg Klodpfx Aoyq Tb Ijqgot Infeed with product de-clumper / product breakup breaker and sieve. Incline screw auger to high level hopper and mixer. Delivery system to bag filler where weighing takes place and metal detection before bag filling point. This system comes with a second mobile screw auger for filling 1000kg big bag / sacks Complete with all the controls for the smooth running of this bagging line. After Bagging the bags are sealed with a Saxon Bag Sealer and then stitched with a Singer Bag Stitcher.

Condition: new, Year of construction: 2021, New 4 Head Automatic Capper & Cap Feeder Never Used / New Model RCP-141 Ksdpfx Aqev R I D Hsgolt To include Capper Feeder & automatic capper machine

Condition: like new (used), Miwe condo 80x60 stonefloor oven with steam function in good working condition if you have further questions please sent an request Kodpsumm Nvsfx Aqgjlt

Condition: good (used), Saxon Bag Sealer With Reverse Facility With Top Bag Cutter With Hydraulic Lift Mast Kljdpfev Dm Epex Aqget Stainless Steel 230 Volt Power Supply

Condition: good (used), Saxon Bag Sealer Kodpfjv Dm Dlox Aqgjlt Stainless Steel With Stainless Steel Conveyor 230 Volts Single Phase Power Height adjustable mast Mobile on castors Fixed adjustable feet also Conveyor belt dimensions 1500mm L x 400mm W

Condition: excellent (used), Year of construction: 2016, Loma Systems Metal Detector with Rejector Ksdpfx Aov T Ah Eoqgslt Model: IQ³ Model conveyor: MD Conveyor, serial number: G7B3C2RS-35150D Year of construction: 2016 220-240 V, 1 Ph, 50/60 Hz, 3 A Belt width: 300 mm, clearance: 350 mm x 150 mm Total dimensions: 2020 mm x 1080 mm x 1120 mm

Condition: good (used), Floor weighing scale K-PZ Weigher indicator Type: KPZ 52E-9-1 Maximum weight: 300 kg Minimum weight: 2 kg, e=: 0.1 kg, T=- 300 kg Dimensions: 800 mm x 1100 mm x 100 mm Kjdpfxsx Hz Dqs Aqgelt Including ramp

Condition: used, Year of construction: 2020, Orangeworks Stainless Steel Mixer Tank Qty 2 in stock Capacity 500 LTS Load cells Mixer Ancillary equipment included Kljdpowq Sz Usfx Aqgjt

Condition: new, New Conveyor with overhead feeder hopper Kljdpfx Aqowd Nthegst Both units are mobile on castors Feeder hopper with opening end door, adjustable exit gate to conveyor Feeder hopper dimensions 800mm x 740mm x 600mm deep Conveyor belt dimensions 1800mm x 230mm W x 1260mm H Conveyor height is adjustable VFD on conveyor drive

Condition: good (used), Perfecta BSB 3L Paper Jogger with Roller The machine is 100% functional and in perfect condition. This is the latest design from a German manufacturer. Klodpfxjy Sd T Es Aqgot Year of manufacture: 2016. Technical specifications: Maximum format: 1150x900mm Stack height: 160mm Weight: 550kg Power supply: 400V Air squeezing roller Air table with micro-perforation Tilt angle adjustment Jogging frequency adjustment (inverter) Adjustable force and speed of the air squeezing roller. Chrome-plated table surface Full documentation set.

Year of construction: 2025, condition: new, Curing ovens shown in the photos can vary in price depending on size, configuration, and optional features. 💡📏⚙️ At ROMER, we manufacture both standard models and fully bespoke solutions, tailored to your process requirements. 🏭✅ Tell us your part size, line capacity, curing profile, and available space - and we will propose the best setup and the options that actually improve daily performance. 🔥🎯 🧠📡 Control and monitoring Live process control for temperature, time, airflow, and modes - with alarms and saved recipes for repeatable cycles. 🔁✅ 🔥🧩 Heating module Fast heat-up and stable temperature thanks to efficient heating elements and quick energy transfer. ⚡🌡️ 🌀💨 Air circulation Uniform airflow reduces temperature differences for consistent coating quality. 🎯✅ 🧱❄️ Insulation and design Smart chamber construction minimizes heat loss - faster reaching setpoint, lower consumption. ♻️📉 🛡️⚠️ Safety and certification Sensors, interlocks, and protection logic increase safety and reliability. 🔒👷 ⚡💰 High efficiency Kodofx Nfmepfx Aqgolt Optimized heat transfer and reduced losses mean real operating savings. 📉🔥 ⏰🤖 Automatic start Programmable schedule - automatic preheating before the shift for smoother production starts. ⏱️✅ 🚪🔒 Self-latching doors + intelligent chimney Prevents accidental opening, chimney activates only when needed for safer operation. 🧯✅ 🌿🔋 ECO mode Low-energy standby when idle - fuel consumption reduction up to 20% (depending on process). 🌱📉 👀💡 View and lighting Inspection without opening the door - fewer temperature drops, easier supervision. ✨👁️ 🛤️🔥 Guide rails + automatic hood Heat hood runs only during loading to reduce temperature loss, automatic rail infeed improves ergonomics and loading speed. 🙌⚙️ 🎛️🌡️ MULTI-ZONE HEAT Independent zone control for uniform curing of parts with different mass and geometry. 🧩✅ 🧠♨️ MTS system Heating elements mounted without thermal bridges - higher efficiency and faster time to set temperature. ⚡⏱️ 2-in-1 🧱↔️🧱 Split chamber Movable partition for two independent zones - drying and curing in one unit for maximum flexibility. 🚀🔁 🎚️🌀 VFD ventilation Variable fan speed based on chamber conditions - better control and lower electricity use. ⚙️💡

Year of construction: 2020, condition: new, Transport systems Depending on the customer's requirements, transport systems can move on the floor or be suspended on poles. - For comfortable solutions for manual installations, we recommend suspended cross traverses (cross transport). - For automated systems, chain conveyors are most often used that do not stop and are a great solution for companies that focus on quality and repeatability of the process. - For companies that make different items at once and have e.g. several cabins with different colors, flexible solutions with the use of the power-and-free conveyor are used. This is the most expensive solution. All installations are made to measure, depending on the customer's requirements. Continuous suspended chain transport systems are designed and manufactured to individual customer orders. In this system, it is also possible to make bottom conveyor systems on which details are placed, e.g. flower pots, rims (photo). ROMER also manufactures suspended transport systems. Crossbeams (cross transports) are designed and made for the needs of specific installations The use of one photocell The use of one photocell in the space of the detail allows you to measure its length and, consequently, gives the option of switching on the guns when the detail appears in their range, and switching off the guns immediately after painting the detail. The photocell is standard equipment. Identification of details by means of special markers. Ksdpfx Asfz Dubjqgolt Above the sling there are plates with identification holes. Based on them, the PLC controller in conjunction with the photocell recognizes the painted detail, turns the guns on and off in good time - thus saving energy and powder paint. Vertical shape detection. The use of light gates with horizontal detectors allows the PLC controller to analyze the shape of a detail vertically. The PLC controller counts the time in which the detail should appear in the gun space - thanks to this it is possible to selectively turn the guns on or off. Using light gates with multiple sensors horizontally and vertically. This solution allows precise measurement of workpiece dimensions, thanks to which it is also possible to control manipulators.

Year of construction: 2020, condition: new, PLC microprocessor control • HMI operator panel Ksdpfjfz Dvcjx Aqgjlt • Phases changed manually or automatically - temporarily • Two separate circuits for water and chemistry, closed circuit • Intelligent control - in the event of a power cut / sudden shutdown, no mixing of liquids possible The control box is made of IP54 technology User manual, Declaration of conformity, 12 months warranty. ROMER pressure washers use metal sheet that provides protection against chemicals. The washer walls protect against splashing, thanks to the closed chemistry loop, the process can be carried out with small amounts of chemistry. Due to the small amount of refrigerant required, it is easy to heat and cheaper to buy, it also allows you to wash large dimensions impossible to wash in bath tubs. Filtration system Thanks to the filtration system, the chemistry works in a closed circuit, 3 filters of different thickness are used, which prevent garbage and grease from entering the circulation. The chemistry is stored in heated stainless steel tanks from where it is fed by a pump under pressure to the lance Washing of dimensions The pressure washer allows washing of large elements, optionally has a rotating platform that allows rotation of the cleaned element, elements can be applied to it with a forklift or crane. High pressure pumps The car wash has two preparation phases, both treatments have separate sets of pipes, pumps, wires and guns to minimize mixing of these agents during phase change. Drains have separate valves that manage the return of funds. The carwash is equipped with a logic controller that controls all components. The chemistry is pumped up to 20 bar using a very durable, acid-resistant AISI304 pump with several stages, 3 kW. The rinsing phase uses a high pressure piston pump with ceramic pistons with a capacity of 3kW and provides 160 - 200 bar.

Year of construction: 2020, condition: new, An automatic car wash is a solution that allows you to reduce costs, improve quality and increase the efficiency of the surface preparation process. The automatic car wash is equipped with a set of pumps for spraying, it has been designed so that as little liquid as possible migrates to subsequent processes after the process, saving money and improving the quality of washing. This is very important, because the apparent savings in systems made without the use of these solutions may generate much higher costs in the future related to chemicals and waste disposal, which will be simply more. Attention should also be paid to problems with maintaining the required bath parameters. Research and development works allowed us to develop a car wash with the function of drying details (Option) with hot air blown by a set of fans after the washing process. The car wash is equipped with an advanced system of creating own macro programs, which can consist of 10 steps each, depending on the number of tanks, the processes can be repeated, their order can be changed, etc. Each of the tanks has its own unique icon and name, enabling the operator to work intuitively. Optionally, the tanks can be equipped with bath replenishment systems, which can be carried out e.g. between processes or at the end of the cycle. • Controls installed on a swivel arm for better access • PLC microprocessor control • 7 "touch control panel • A very large number of nozzles compared to other solutions • (Option) Possibility of drying details after washing • Ability to create your own advanced programs • Advanced system of dampers made of acid-proof steel sheets, double secured with limit switches • Control system for tight closing and full opening of the flaps • To minimize fluid mixing, separate lines, nozzles, tanks for each treatment • Intelligent control - in the event of a power cut / sudden shutdown, the fluids cannot be mixed • Fully automatic operation Ksdpfsfz I Hxox Aqgslt

Year of construction: 2020, condition: new, Washers Ultrasonic Baths for washing, phosphatizing, chromating, degreasing, removing paint coatings materials Klsdefz I N Tjpfx Aqgst In ROMER Ultrasonic Washers, stainless steel is used which provides protection against acids. Bathtubs have an additional insulation wall, so they do not lose temperature and heat up faster. Good quality materials ensure long life of the vibrating elements. Heating system The heaters used in the ROMER bathtubs are made of the highest quality materials and are made of high temperature resistant ceramic elements. The heating system used ensures great thermal efficiency, hot water automatically mixes with cold water, heating the entire bathtub. Ultrasonic transducers Ultrasonic elements used in ROMER washers are installed in immersion modules, which better reflect vibrations and are exchangeable. The ultrasound range is 20-40kHz depending on the washed element, lower frequencies are used for large elements of high strength, lower for jewelry, sensitive mechanical systems, etc. All transducers are connected by high temperature resistant cables.

Year of construction: 2020, condition: new, An automatic car wash is a solution that allows you to reduce costs, improve quality and increase the efficiency of the surface preparation process. The automatic car wash is equipped with a set of pumps for spraying, it has been designed so that as little liquid as possible migrates to subsequent processes after the process, saving money and improving the quality of washing. This is very important, because the apparent savings in systems made without the use of these solutions may generate much higher costs in the future related to chemicals and waste disposal, which will be simply more. Attention should also be paid to problems with maintaining the required bath parameters. Research and development works allowed us to develop a car wash with the function of drying details (Option) with hot air blown by a set of fans after the washing process. The car wash is equipped with an advanced system of creating own macro programs, which can consist of 10 steps each, depending on the number of tanks, the processes can be repeated, their order can be changed, etc. Each of the tanks has its own unique icon and name, enabling the operator to work intuitively. Optionally, the tanks can be equipped with bath replenishment systems, which can be carried out e.g. between processes or at the end of the cycle. • Controls installed on a swivel arm for better access • PLC microprocessor control • 7 "touch control panel • A very large number of nozzles compared to other solutions • (Option) Possibility of drying details after washing • Ability to create your own advanced programs Kledpofz Nblsfx Aqget • Advanced system of dampers made of acid-proof steel sheets, double secured with limit switches • Control system for tight closing and full opening of the flaps • To minimize fluid mixing, separate lines, nozzles, tanks for each treatment • Intelligent control - in the event of a power cut / sudden shutdown, the fluids cannot be mixed • Fully automatic operation