Nickel 200, 201 Forged Fittings Manufacturers, Suppliers – Nickel 200, 201 Socket Weld Pipe Fittings, Nickel 200, 201 Threaded Pipe Fittings – Pure Nickel Forged Fittings
- Nickel 200, 201 Threaded Pipe Fittings – Nickel 200, 201 90° Elbow, Nickel 200, 201 45° Elbow, Nickel 200, 201 Tee, Nickel 200, 201 Cross, Nickel 200, 201 Full Coupling, Nickel 200, 201 Half Coupling, Nickel 200, 201 Reducing Coupling, Nickel 200, 201 Pipe Cap, Nickel 200, 201 Hex Head, Nickel 200, 201 Bushing, Nickel 200, 201 Hex Head Plug, Nickel 200, 201 Square Head Plug, Nickel 200, 201 Round Head Plug, Nickel 200, 201 Union, Nickel 200, 201 Hex Nipple, Nickel 200, 201 Street Elbow, Nickel 200, 201 Bull Plug, Nickel 200, 201 Boss, Nickel 200, 201 Swage Nipple, Nickel 200, 201 Pipe Nipple, Nickel 200, 201 Adapter, Nickel 200, 201 Union (Male x Female), Nickel 200, 201 Branch Outlet, Nickel 200, 201 90° Elbow Outlet, Nickel 200, 201 45° Lateral Tee, Nickel 200, 201 Lateral Outlet, Nickel 200, 201 Nipple Branch Outlet
- Nickel 200, 201 Socket Weld Pipe Fittings – Nickel 200, 201 90° Elbow, Nickel 200, 201 45° Elbow, Nickel 200, 201 Tee, Nickel 200, 201 Cross, Nickel 200, 201 Full Coupling, Nickel 200, 201 Half Coupling, Nickel 200, 201 Pipe Cap, Nickel 200, 201 Union, Nickel 200, 201 Reducer Insert, Nickel 200, 201 Boss, Nickel 200, 201 Branch Outlet, Nickel 200, 201 90° Elbow Outlet, Nickel 200, 201 45° Lateral Tee, Nickel 200, 201 Lateral Outlet, Nickel 200, 201 Branch Outlet Butt Weld, Nickel 200, 201 90° Elbow, Nickel 200, 201 Outlet Butt Weld, Nickel 200, 201 Lateral Outlet Butt Weld, Nickel 200, 201 Nipple Branch Outlet Butt Weld
- Size: From 1/4″ to 4″ (6mm-100mm), Pressure: 2000LBS, 3000LBS, 6000LBS, 9000LBS.
- Standard specification of Nickel 200, 201 forged fittings is ASTM B366.
- Metallica is a well known manufacturer and supplier of Nickel 200, 201 forged pipe fitting for the clients from oil and gas, petrochemicals, railway, construction and other industries. We manufacture different size and shapes of Nickel 200, 201 forged pipe fittings by open die forging, closed die forging and drop forging. Our main products include Nickel 200, 201 socket weld and Nickel 200, 201 threaded pipe fittings in size range of 1/4″ to 4″ (6mm-100mm), with pressure rating of 2000LBS, 3000LBS, 6000LBS, and 9000LBS.
- Nickel 200, 201 Forged socket weld and Nickel 200, 201 threaded pipe fittings are generally used for small size pipes and piping systems (generally below 4 inches in diameter for Class 3000, and below 2 inches for fittings in class 6000 and 9000). Nickel 200, 201 Forged pipe fittings are manufactured by forging, followed by heat treatment and machining solid steel as per ASME B16.11 and other dimensional standards. For bigger size piping systems Nickel 200, 201 buttweld pipe fittings produced as per ASME B16.9 are used.
Nickel 200, 201 Forged Pipe Fittings Manufacturers
Types of Nickel 200, 201 Socket Welded & Nickel 200, 201 Threaded Forged Steel Pipe Fittings
- Nickel 200, 201 Alloy Elbows (90 Degree Elbows and 45 Degree Elbows) – A pipe elbow is a forged steel fitting installed between two lengths of pipe or tube allowing a change of direction, usually in the 90° or 45° direction. Similar to a reducing tee, reducing elbows also exist to simultaneously change flow direction and reduce flow diameter. Street Elbows have one female end to accept pipe and another male end thread that is the same size as the pipe and can avoid the use of a pipe nipple during installation.
- Nickel 200, 201 Tees (Equal Tee and Reducing Tees)- Tees are a type of forged steel fitting used to combine or divide process flow, and Reducing Tees additionally allow for pipe size change. The run outlets of the tee are the two in-line outlets, and the branch is the third outlet. The branch outlet is the reducing outlet in a reducing tee.
- Nickel 200, 201 Couplings (Straight and Reducing Couplings, Full and Half Couplings) – Couplings are a forged steel fitting used to connect two lengths of pipe, and Half-coupling is screwed onto the pipe, while the other end is made to be tightly inserted, or welded, onto the other end to pipe or vessel. Standard Couplings have female threads or open sockets at both ends, whereas reducing couplings connect smaller pipes to larger ones.
- Nickel 200, 201 Unions (Socket Weld Unions and Threaded Unions) – Unions are a forged steel fitting similar to a coupling but allow a convenient disconnection and connection; it has 3 parts: a nut, a female end, and a male end. They allow two lengths of pipe to be assembled and detached without causing any deformation to the pipes.
- Nickel 200, 201 Bushings (Hex Head Bushings and Flush Bushings) – Reducing inserts and Bushings are forged steel fittings that allow for a change in pipe size. Pictured here is the hex head bushing, which is most commonly used.
- Nickel 200, 201 Caps (Pipe Caps and End Caps) – Caps are forged steel fittings used to terminate the flow, inserting over the end of the pipe.
- Nickel 200, 201 Plug (Square Head Plugs, Hex Head Plugs and Round Head Plugs) – Similar to a cap, plugs are forged steel fittings that are inserted into the end of the pipe, and they come with different head types, including: hex, square, and round.
- Nickel 200, 201 Cross – Crosses are a 4-way forged steel fitting, with 1 inlet and 3 outlets or vice versa. These are sometimes referred to as 4-way tees.
- Nickel 200, 201 Outlets (Weldolets, Sockolets, Threadolets, Elbolets, Latrolets and Nipolets)
- Nickel 200, 201 Nipples (Hexagonal Nipples and Swaged Nipples)
Nickel 200/201 Forged Fittings Stock & Supply Range
Product | Nickel 200/201 Forged Fittings |
Standard | ASTM B366 / ASME SB 366 |
Equivalents | Alloy 201, UNS N02201, 2.4068 | Alloy 200, UNS N02200, 2.4066 |
Size | 1/2″ to 18″; Thickness 0.6mm to 20mm |
Dimensions | ANSI/ASME B16.9, B16.28, MSS-SP-43 |
Schedule | SCH5, SCH10, SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120, SCH140, SCH160, XXS |
Specifications | ASTM, ASME, DIN, GOST, JIS |
Fittings Type | Butt Weld, Screwed & Socket Weld, Flanges, Instrumentation |
Other Fittings Type | Elbows, Tees, Reducers, Caps, Stub Ends, Flanges (ANSI, Table E, D and H), Nuts, Bolts, Screws, Threaded Bars, Seamless, Welded, Elbow, Tee, Cross, Concentric & Eccentric Reducer, Pipe End Caps, Stub Ends, Bends, Dairy Fittings, etc. |
Certification | EN 10204 3.1 |
Nickel 200/201 Products & Manufacturing Standards
Products Form | Standard |
Alloy 200/201 Rod and bar | ASTM B160, DIN 17752, ISO9723 |
Alloy 200/201 Pipe and Tube | ASTM B161, B163, B725, B730, B751, B775, B829, DIN 17751, ISO 6207 |
Alloy 200/201 Plate, Sheet & Strip | ASTM B162, DIN 17750, ISO 6208 |
Alloy 200/201 Buttweld Fittings | ASTM B366 |
Alloy 200/201 Forgings (Flange, Fittings and Forgings) | ASTM B564, ISO 9725, DIN 17754 |
Alloy 200/201 Wire | DIN 17753, ISO 9724 |
Chemical Composition of Nickel 200/201 Forged Fittings
Element | Nickel 200 | Nickel 201 |
Nickel (plus Cobalt) | 99.0 minimum | 99.0 minimum |
Copper | 0.25 | 0.25 |
Iron | 0.4 | 0.4 |
Manganese | 0.35 | 0.35 |
Carbon | 0.15 | 0.02 |
Silicon | 0.35 | 0.35 |
Sulfur | 0.01 | 0.01 |
- Weight % (all values are maximum unless a range is otherwise indicated)
Mechanical Properties of Nickel 200/201 Forged Fittings
Yield Strength 0.2% Offset | Ultimate Tensile Strength | Elongation in 2 inches | Hardness | ||||
ksi | MPa | ksi | MPa | % | Brinell (3000-kg) | Rockwell B | |
Nickel 200 | 15–40 | 105–275 | 55–80 | 380–550 | 60–40 | 90–140 | 45–73 |
Nickel 201 | 12–35 | 83–240 | 50–70 | 345–485 | 60–40 | — | — |
Physical Properties of Nickel 200/201 Forged Fittings
Density: | 8.885 g/cm³ |
Young’s modulus at 25.6°C: | 2.05 x105 Mpa |
Melting range: | 1435-1446°C |
Specific heat at 25.6°C: | 456.4 J/(kg*K) |
Thermal conductivity at 25.6°C: | 724.7 kcal/(hr.m.°C) |
Electrical Resistivity at 25.6 °C: | 9.6 x10^-8 Ωm |
What are the Properties of Nickel 200/201 Forged Fittings?
Nickel 200 and 201 General Guideline for Corrosion Resistance | |||
---|---|---|---|
Sulfuric Acid | Good | Organic Acids | Excellent |
Phosphoric Acid | Good | Strong Alkalis | Excellent |
Hydrochloric Acid | Good | Reducing Salts | Excellent |
Hydrofluoric Acid | Excellent | Oxidizing Salts | Not recommended |
Nitric Acid | Not Recommended | Seawater | Good |
- Heat-Resistant Applications. Nickel-base alloys are used in many applications where they are subjected to harsh environments at high temperatures. Nickel-chromium alloys or alloys that contain more than about 15% Cr are used to provide both oxidation and carburization resistance at temperatures exceeding 760°C. Nickel 200 is normally limited to service at temperatures below 600ºF (315ºC), since at higher temperatures it can suffer from graphitization which can severely compromise properties. At higher temperatures Nickel 201 should be utilized. Both grades are approved under ASME Boiler and Pressure Vessel Code Section VIII, Division 1. Nickel 200 is approved for service up to 600ºF (315ºC), while Nickel 201 plate is approved up to 1250ºF (677ºC).
- Corrosion Resistance:- Nickel-base alloys offer excellent corrosion resistance to a wide range of corrosive media. However, as with all types of corrosion, many factors influence the rate of attack. The corrosive media itself is the most important factor governing corrosion of a particular metal.
- Nickel 200 (UNS N02200) and 201 (UNS N02201) are dual-certifiable wrought nickel materials. They differ only in the maximum carbon levels present—0.15% for Nickel 200 and 0.02% for Nickel 201.
- Nickel 200 and 201 are ferromagnetic and exhibit highly ductile mechanical properties across a wide temperature range. Both grades are easily welded and processed by standard shop fabrication practices.
- Alloy 200/201 is extremely resistance to caustic alkalies up to and including the molten state. The extra-low carbon content of Alloy 200/201 gives virtual immunity to intergranular attack above about 315°C. The presence of chlorates must be kept to a minimum, as they accelerate the rate of attack.
- Commercially pure wrought Nickel with good mechanical properties over a wide range of temperature and excellent resistance to many corrosives, in particular hydroxides.
- Good resistance to corrosion in acids and alkalis and is most useful under reducing conditions. In acid, alkaline and neutral salt solutions the material shows good resistance, but in oxidizing salt solutions severe attack will occur.
- Resistant to all dry gases at room temperature and in dry chlorine and hydrogen chloride may be used in temperatures up to 550C.
- Resistance to mineral acids varies according to temperature and concentration and whether the solution is aerated or not.
- Corrosion resistance is better in de-aerated acid.
What are the Applications of Nickel 200/201 Forged Fittings?
Nickel 200/201 is used in viscose rayon and polymer production, food processing, reactors, tubes, aerospace engineering, military and other applications.
- Chemical processing and storage
- Food processing equipment
- Salt production
- Caustic handling equipment
- Synthetic fiber production
- Manufacturing equipment, reactors and vessels where sodium hydroxide and fluorine is used
- Aerospace and defense
Types of Nickel and Nickel Alloy Products
Nickel Balls | Nickel Honeycomb | Nickel Rod |
Nickel Bands | Nickel Ingot | Nickel Samples |
Nickel Bars | Nickel Ink | Nickel Shaving |
Nickel Blocks | Nickel Insulated Wire | Nickel Sheets |
Nickel Board | Nickel Lump | Nickel Shot |
Nickel Chips | Nickel Mesh | Nickel Single Crystal |
Nickel Chunk | Nickel Metal | Nickel Sleeves |
Nickel Coil | Nickel Microfoil | Nickel Slugs |
Nickel Concentrate | Nickel Microleaf | Nickel Specimens |
Nickel Crucibles | Nickel Nanocrystalline Foil | Nickel Spheres |
Nickel Cubes | Nickel on Silica/Alumina Catalyst | Nickel Spheres, Silver-coated |
Nickel Cylinder | Nickel Parts | Nickel Sponge |
Nickel Disc | Nickel Particles | Nickel Spring |
Nickel Electrodes | Nickel Paste | Nickel Strip |
Nickel Flake | Nickel Pellets | Nickel Tape |
Nickel Flanges | Nickel Pieces | Nickel Tube |
Nickel Foam | Nickel Plates | Nickel Wafer |
Nickel Foil | Nickel Powder | Nickel Wire |
Nickel Gauze | Nickel Puck | Nickel Wool |
Nickel Granules | Nickel Ribbon | Ultra Thin Nickel Foil |
Nickel Grids | Nickel Rings |
Testing & Inspection of Nickel 200/201 Forged Fittings
Testing (Destructive, Non Destructive)
Positive Material Identification – PMI Testing | Hydrostatic Test |
Chemical Analysis – Spectro Analysis | Hydrogen-Induced Cracking (HIC) Test |
Mechanical Testing Such as Tensile, Elongation, Reduction of Area | Sulfide Stress Corrosion Cracking (SSC), NACE TM 0177 |
Micro Test | Radiography Test |
Macro Test | Dye Penetrant Test (DP Test) |
Hardness Test | Ultra Sonic Test (UT) |
Pitting Resistance Test | Eddy Current Testing |
Intergranular Corrosion (IGC) Test | Impact Test |
Flaring Test | Bend Test |
Flattening Test |
Inspection
- Our internal inspection reports would be provided for all the goods before shipment.
- Buyers or their associates are most welcome to visit us for personal inspect
- We regularly have inspections ongoing at our premises from internationally acclaimed Inspection Agencies such as TUV, BVIS, SGS, Llyods, DNV etc.
Prices for Nickel 200/201 Forged Fittings
Prices for Nickel 200/201 Forged Fittings are directly co related to prices of the raw materials such as iron ore, metal scrap, chromium, nickel and various other alloying elements. The production cost of heat resistant stainless steel and nickel plates is high as they contain high amount of nickel and chromium. Meanwhile, mild steel material is among the lowest cost steel available, followed by carbon steel, 400 series stainless steels, aluminium, alloy steel, and 300 series stainless steel. Special alloys such as titanium, Inconel, Monel and Hastelloy cost very high as the nickel, chromium and moly content is very high.
For special and discounted prices for various types of Nickel 200/201 Forged Fittings, please feel free to contact us through email, phone or whatsapp.
We are also regularly publishing our price list for various steel products on our blog.
Documents Provided at the time of Domestic Sales or Export of Nickel 200/201 Forged Fittings
Certificate of Origin | Raw Material Test Reports |
Commercial Invoice | Heat Treatment Charts |
Packing List | Quality Assurance Plan (QAP) |
Fumigation Certificates | NABL approved Laboratory Test Reports |
Letter of Guarantee | Material Test Certificates |
ROHS Certificate | Certificate of Compliance/Conformity |
Price Terms for Nickel 200/201 Forged Fittings
We can offer any of the following price basis depending on your requirement:
- Ex-works
- FOR Site in India
- FOB Nhava Sheva
- CFR, CIF, CPT your destination port
- Door to Door Delivery Duty Paid as well as Duty Unpaid
Delivery Time of Nickel 200/201 Forged Fittings
- If the items are available in stock, we take 2 days from the date of receipt of advance payment to clear the shipment and send it to port.
- And in-case the items are not available in stock, the time taken for manufacturing depends on the size, quantity and grade.
- However we can claim the fact that we can compete with anyone in India on Delivery time and most of the time our production time is the least.
- We have tied up with strong logistic partners in India which can undertake any type of shipping activities and make sure that there is no delay in shipment.
Marking & Packing of Nickel 200/201 Forged Fittings
- All our products will have complete marking details which are co-related to the test certificates we supply.
- In case of orders for cut piece of Pipes, Sheets or Round Bars, the marking is transferred from the product from which it is cut. In such cases we provide Letter confirming the marking transfer and picture of the product from which it is cut.
- All goods are packed in wooden cases or pallets.
Suppliers of Nickel 200/201 Forged Fittings in India
Mumbai, Delhi, Bangalore, Hyderabad, Ahmedabad, Chennai, Kolkata, Surat, Pune, Jaipur, Visakhapatnam, Kanpur, Nagpur, Lucknow, Thane, Bhopal, Indore, Pimpri Chinchwad, Patna, Vadodara, Ghaziabad, Ludhiana, Agra, Nashik, Faridabad, Meerut, Rajkot, Kalyan-Dombivli, Vasai-Virar, Varanasi, Srinagar, Aurangabad, Dhanbad, Amritsar, Navi Mumbai, Allahabad, Howrah, Ranchi, Gwalior, Jabalpur, Coimbatore, Vijayawada, Jodhpur, Madurai, Raipur, Chandigarh, Guntur, Guwahati, Solapur, Hubli–Dharwad, Mysore, Tiruchirappalli, Bareilly, Moradabad, Tiruppur, Gurgaon, Aligarh, Jalandhar, Bhubaneswar, Salem, Mira-Bhayandar, Warangal, Jalgaon, Kota, Bhiwandi, Saharanpur, Gorakhpur, Bikaner, Amravati, Noida, Jamshedpur, Bhilai, Cuttack, Firozabad, Kochi, Nellore, Bhavnagar, Dehradun, Durgapur, Asansol, Rourkela, Nanded, Kolhapur, Ajmer, Akola, Gulbarga, Jamnagar, Ujjain, Loni, Siliguri, Jhansi, Ulhasnagar, Jammu, Sangli-Miraj & Kupwad, Mangalore, Erode, Belgaum, Ambattur, Tirunelveli, Malegaon, Gaya, Thiruvananthapuram, Udaipur, Kakinada, Davanagere, Kozhikode, Maheshtala, Rajpur, Sonarpur, Rajahmundry, Bokaro, South Dumdum, Bellary, Patiala, Gopalpur, Agartala, Bhagalpur, Muzaffarnagar, Bhatpara, Panihati, Latur, Dhule, Tirupati, Rohtak, Sagar, Korba, Bhilwara, Berhampur, Muzaffarpur, Ahmednagar, Mathura, Kollam, Avadi, Kadapa, Kamarhati, Sambalpur, Bilaspur, Shahjahanpur, Satara, Bijapur, Kurnool, Rampur, Shimoga, Chandrapur, Junagadh, Thrissur, Alwar, Bardhaman, Kulti, Nizamabad, Parbhani, Tumkur, Khammam, Ozhukarai, Bihar Sharif, Panipat, Darbhanga, Bally, Aizawl, Dewas, Ichalkaranji, Karnal, Bathinda, Jalna, Eluru, Barasat, Kirari Suleman Nagar, Purnia, Satna, Mau, Sonipat, Farrukhabad, Durg, Imphal, Ratlam, Hapur, Arrah, Anantapur, Karimnagar, Etawah, Ambarnath, North Dumdum, Bharatpur, Begusarai, New Delhi, Gandhidham, Baranagar, Tiruvottiyur, Pondicherry, Sikar, Thoothukudi, Rewa, Mirzapur, Raichur, Pali, Ramagundam, Haridwar, Vijayanagaram, Tenali, Nagercoil, Sri Ganganagar, Karawal Nagar, Mango, Thanjavur, Bulandshahr, Uluberia, Katni, Sambhal, Singrauli, Nadiad, Secunderabad, Naihati, Yamunanagar, Bidhannagar, Pallavaram, Bidar, Munger, Panchkula, Burhanpur, Raurkela Industrial Township, Kharagpur, Dindigul, Gandhinagar, Hospet, Nangloi Jat, Malda, Ongole, Deoghar, Chapra, Haldia, Khandwa, Nandyal, Morena, Amroha, Anand, Bhind, Bhalswa Jahangir Pur, Madhyamgram, Bhiwani, Berhampore, Ambala, Morbi, Fatehpur, Raebareli, Mahaboobnagar, Chittoor, Bhusawal, Orai, Bahraich, Vellore, Mehsana, Raiganj, Sirsa, Danapur, Serampore, Sultan Pur Majra, Guna, Jaunpur, Panvel, Shivpuri, Surendranagar Dudhrej, Unnao, Chinsurah, Alappuzha, Kottayam, Machilipatnam, Shimla. Adoni, Udupi, Katihar, Proddatur, Saharsa, Hindupur, Sasaram, Hajipur, Bhimavaram, Kumbakonam, Dehri, Madanapalle, Siwan, Bettiah, Guntakal, Srikakulam, Motihari, Dharmavaram, Gudivada, Phagwara, Narasaraopet, Suryapet, Miryalaguda, Tadipatri, Karaikudi, Kishanganj, Jamalpur, Ballia, Kavali, Tadepalligudem, Amaravati, Buxar, Jehanabad, Aurangabad, Gangtok
Exporters of Nickel 200/201 Forged Fittings
- America: Antigua and Barbuda, Argentina, Aruba, Bahamas, Barbados, Belize, Bermuda, Bolivia, Brazil, Canada, Cayman Islands, Chile, Colombia, Costa Rica, Cuba, Dominica, Dominican Republic, Ecuador, El Salvador, Grenada, Guatemala, Guyana, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, Suriname, Trinidad and Tobago, United States, Uruguay, Venezuela
- Europe – Albania, Andorra, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Euro area, Faroe Islands, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Isle of Man, Italy, Kosovo, Latvia, Liechtenstein, Lithuania, Luxembourg, Macedonia, Malta, Moldova, Monaco, Montenegro, Netherlands, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom
- Africa – Algeria, Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Cape Verde, Central African Republic, Chad, Comoros, Congo, Djibouti, Egypt, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea Bissau, Ivory Coast, Kenya, Lesotho, Liberia, Libya, Madagascar, Malawi, Mali, Mauritania, Mauritius, Morocco, Mozambique, Namibia, Niger, Nigeria, Republic of the Congo, Rwanda, Sao Tome and Principe, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Swaziland, Tanzania, Togo, Tunisia, Uganda, Zambia, Zimbabwe
- Asia – Afghanistan, Armenia, Azerbaijan, Bahrain, Bangladesh, Bhutan, Brunei, Cambodia, China, East Timor, Georgia, Hong Kong, Indonesia, Iran, Iraq, Israel, Japan, Jordan, Kazakhstan, Kuwait, Kyrgyzstan, Laos, Lebanon, Macao, Malaysia, Maldives, Mongolia, Myanmar, Nepal, Oman, Palestine, Philippines, Qatar, Saudi Arabia, Singapore, South Korea, Sri Lanka, Syria, Taiwan, Tajikistan, Thailand, Turkmenistan, United Arab Emirates, Uzbekistan, Vietnam, Yemen
- Australia – Australia, Fiji, Kiribati, New Caledonia, New Zealand, Papua New Guinea, Samoa, Solomon Islands, Tonga, Vanuatu