ASME B16.9 fittings for nickel HPAL and RKEF plants

Where ASME B16.9 fittings go in an HPAL plant

HPAL leaches limonite ore with sulphuric acid at about 250–270 °C in pressure autoclaves. The circuits around the autoclave combine acid, solids and heat, so each one needs its own fitting specification.

• ✓ Autoclave feed and preheating: high-pressure slurry feed and flash-steam preheater lines. Heavy-wall A234 WPB before acid addition; A815 duplex or 904L where acidic condensate or carry-over is expected.
• ✓ Discharge, flash and let-down: the most severe service in the plant. Titanium and lined construction dominate at the hottest points; steel and nickel alloy fittings serve flash steam, vents and cooler connections where the designer specifies them.
• ✓ CCD washing and neutralisation: large, acidic slurry lines. WP316L, WP317L and duplex S32205 are typical metal choices alongside rubber-lined and HDPE pipe.
• ✓ Sulphuric acid plant: strong-acid circulation, acid coolers, dilution points and the waste-heat boiler. WPB for low-velocity strong acid, B366 Alloy 20 or 904L for hotter or weaker acid, WP11 / WP22 and WPB on the steam side.
• ✓ MHP precipitation: near-neutral but abrasive magnesia slurry. WP316L, or duplex where chlorides build up.
• ✓ Nickel sulphate refining and crystallisation: hot, mildly acidic sulphate liquor. WP316L, WP317L, 904L or duplex, with Alloy 20 or C-276 on the more acidic streams.

RKEF smelters and captive power

RKEF ferronickel and nickel pig iron lines use large volumes of cooling water for furnace shells, electrodes and tapholes, plus fuel, off-gas, nitrogen and compressed air lines — mostly A234 WPB, with WP304L / WP316L for treated water and duplex or super duplex where seawater is used for cooling. The captive coal and LNG power plants that serve nickel industrial parks use A234 WP91 or WP22 on main steam and hot reheat, and WPB or WP11 on feedwater, cold reheat and auxiliary steam. This is the same boiler-grade work we do for Indian power plants under IBR.

Material selection by service

Typical industry practice only, not a guaranteed or recommended selection. Final grades depend on acid strength, chloride level, temperature, solids and the plant designer’s corrosion review; we supply to the grade on your line list.

Titanium: titanium and titanium-lined steel are used in some autoclave, acid injection and hot flash service. We do not make titanium fittings; we make the steel and nickel alloy fittings for the rest of the plant, which is where most of the fitting count sits.

Erosion, abrasion and sulphuric acid

• ✓ In slurry and flashing lines, long-radius elbows and 3D / 5D bends wear far more slowly than short-radius (ASME B16.28-type) elbows. Heavier schedules or target tees are common at the worst changes of direction.
• ✓ Fittings placed straight after a choke or let-down valve take the full jet; designers usually leave a straight run before the first elbow or reducer.
• ✓ Carbon steel is used for 93–98% acid only at low velocity and moderate temperature. Turbulence in elbows and tees strips the protective sulphate film; Alloy 20 and 904L are the usual upgrade.
• ✓ Dilution points, where acid meets water, see local heat and intermediate concentrations; tees and reducers there are often one grade higher than the run pipe.
• ✓ Recycled process water and seawater cooling bring chlorides that pit WP316L; duplex, 904L or super duplex give more margin.

Why buy from us

• ✓ Fittings are manufactured at our group manufacturing facility, Arshya Engineers & Fabrications Pvt Ltd, which holds ISO 9001, ISO 14001, ISO 45001, PED (TÜV Rheinland), AD 2000 HP 0, EN 764-5, IBR and ASME U-Stamp approvals — view the certificates
• ✓ EN 10204 3.1 certificates as standard; 3.2 witnessed by TÜV, Lloyd’s Register, Bureau Veritas, DNV, SGS or your own inspector
• ✓ In-house heat treatment, with heat treatment records and hardness results for Cr-Mo grades
• ✓ About 300 tonnes of fittings capacity and no minimum order: fast spares and small batches of exotic grades such as 904L, Alloy 20, C-276 and super duplex
• ✓ Quotations in USD, EUR or INR
• ✓ PMI, dimensional and visual inspection on every order; UT, RT, MPI or DPI as specified

Shipping to Indonesia and the Philippines

Sea freight from Nhava Sheva (Mumbai) in seaworthy wooden cases, bevel ends protected, each piece marked with heat number, grade, size and schedule. For Indonesian nickel regions — Morowali, Weda Bay, Obi and Pomalaa — we quote CFR or CIF to the port or forwarder you name, usually via a main transhipment hub, and can consolidate several grades in one shipment. Philippine deliveries go to Manila, Davao or the port nearest your site. Commercial invoice, packing list and certificate of origin come with every shipment.

Related: Products · How an export order works · Product catalogue (PDF) · EN 10253 and nickel alloy grades for HPAL (arshyapipefittings.com) · Bahasa Indonesia

Grade pages for 317L, 904L, Alloy 20 and Hastelloy C-276 are on our sister site.