Stainless Steel Fittings

Stainless Steel Instrumentation Fittings and Valves

Stainless steel instrumentation fittings are precision SS 316 connectors that carry process, sample and impulse lines at high pressure without leaking. Vikay Fittings supplies four families: twin-ferrule tube fittings, threaded pipe fittings, butt-weld fittings and instrumentation ball, needle and check valves, in fractional and metric series.

Vikay Fittings manufactures stainless steel instrumentation fittings and valves in India under an ISO 9001:2015 quality system, and exports them to refineries, gas plants, mines, OEM panel builders and instrument workshops worldwide. The stainless range covers more than 2,400 catalogued part numbers.

Twin-ferrule tube fittings make a gas-tight, remakeable joint on plain-cut tube and are the default for impulse and sample lines. Threaded pipe fittings such as hex nipples, adapters, reducers and plugs in NPT, ISO tapered and SAE/UNF forms bridge between instruments, manifolds and process ports. Butt-weld fittings suit high-purity and high-integrity circuits where a welded joint is specified. Instrumentation ball valves in 2, 3 and 5-way patterns, panel-mounting and high-pressure variants, complete the loop.

Bodies are machined from SS 316 and 316L bar to ASTM A276 / A479, with 304 available on request. Fractional sizes run 1/8 to 1 inch OD and metric 3 to 25 mm; threads are cut to ASME B1.20.1 (NPT), ISO 7/1, ISO 228 or SAE J514 UNF. Dimensions follow the common industry patterns, so parts drop into existing installations; brand names are used only to identify fitment. Send your part list for a quote.

Frequently Asked Questions

What stainless grade are Vikay instrumentation fittings made from?

Standard production is SS 316 machined from bar to ASTM A276 / A479, with 316L available where a low-carbon grade is specified for welding, and 304 on request. Ferrules are hardened relative to the body so the front ferrule bites the tube rather than the reverse.

Are your tube fittings interchangeable with other instrumentation brands?

The fittings are made to the common twin-ferrule pattern and, size for size and thread for thread, are dimensionally interchangeable with widely used instrumentation tube fittings. Any brand name is used only to describe fitment, not to imply origin or endorsement. As with any twin-ferrule system, do not mix components from different makers within one joint. Match body, nut and both ferrules from the same supplier.

What is the difference between tube fittings, pipe fittings and weld fittings?

Tube fittings clamp onto thin-wall tube with two ferrules and can be broken and remade. Pipe fittings join threaded ports and pipe using NPT, ISO tapered or parallel threads with a sealant or seal ring. Weld fittings are butt-welded to the tube and are permanent, which is chosen where a leak path of any kind is unacceptable or where the line is high purity.

What working pressure do the tube fittings hold?

Rated working pressure is a function of tube outside diameter, wall thickness and material condition, not of the fitting alone. Fully annealed SS 316 tube of 1/4 inch OD by 0.035 inch wall is commonly rated in the region of 5,000 psi, and heavier walls higher. Each part number has a dimensioned datasheet, so ask for it and specify your tube wall on the enquiry.