SS 321 / 321H Instrumentation Tube Fittings Manufacturer, Supplier and Exporter in India
Arrotop is a manufacturer, supplier and exporter of SS 321 / 321H Instrumentation Tube Fittings for heated instrument lines, welded process equipment, furnace systems, refinery units, heat exchangers and other installations exposed to elevated operating temperatures.
Arrotop supplies SS 321 and SS 321H connectors, elbows, tees, unions, bulkhead fittings, adapters, reducer port connectors, ferrules, caps and plugs. Single ferrule and double ferrule fittings are available for both imperial and metric tubing.
SS 321 is a titanium-stabilised stainless steel commonly specified for welded equipment that remains exposed to heat during service. SS 321H has a controlled higher carbon content and is selected where the equipment specification requires greater strength at elevated temperatures.
Arrotop supplies standard fittings, custom connections and replacement components for OEMs, EPC contractors, refineries, process plants, maintenance teams and international buyers.
SS 321 / 321H Fittings for Heated and Welded Instrument Lines
Welded tubing systems installed around furnaces, heaters, exhaust equipment and hot process units may remain exposed to elevated temperatures for long periods. In such systems, the project specification may call for SS 321 or SS 321H instead of a general stainless-steel grade.
Arrotop supplies SS 321 Instrumentation Tube Fittings for welded and heated tubing systems, including connections for:
- Pressure gauges and transmitters
- Temperature-monitoring instruments
- Flow and differential-pressure lines
- Heated gas sampling systems
- Valve and manifold hook-ups
- Furnace pressure-monitoring lines
- Exhaust and flue-gas instruments
- Heat exchanger connections
- Hot process sampling panels
- Thermal equipment control lines
The final fitting selection should match the tubing grade, operating temperature, pressure and original equipment specification.
Available SS 321 / 321H Instrumentation Tube Fittings
Arrotop manufactures the following Instrumentation Tube Fittings in SS 321 and SS 321H:
- Male Connectors
- Female Connectors
- Union Connectors
- Male Elbows
- Female Elbows
- Union Elbows
- Male Run Tees
- Female Run Tees
- Male Branch Tees
- Female Branch Tees
- Union Tees
- Bulkhead Male Connectors
- Bulkhead Female Connectors
- Bulkhead Unions
- Straight Unions
- Reducing Unions
- Union Crosses
- Reducer Port
- Connectors
- NPT Male Adapters
- BSPT Couplings
- BSPP Plugs
- Tube Caps and Tube Plugs
- Front Ferrules
- Back Ferrules
Both SS 321 single ferrule tube fittings and SS 321/321H double ferrule compression fittings are available for standard and custom requirements.
Buyers can send individual fitting enquiries or complete bills of materials for project, shutdown and equipment-manufacturing requirements.
Features of SS 321 / 321H Instrumentation Tube Fittings
- Manufactured in SS 321 / UNS S32100 / EN 1.4541 and SS 321H / UNS S32109, depending on the project requirement.
- Titanium stabilisation makes
- SS 321 suitable for welded instrumentation systems that remain exposed to elevated temperatures.
- SS 321H offers better mechanical strength at high temperatures and is commonly specified for furnace, refinery heater and thermal-processing equipment.
- Suitable for heated sampling lines, hot-gas instrumentation, exhaust systems, heat exchangers and welded process skids.
- Available in single ferrule and double ferrule designs for secure tube connections in high-temperature instrument lines.
- Can be supplied for new equipment, plant maintenance and replacement of existing SS 321 or SS 321H fittings.
- Exact grade marking and material traceability help confirm whether the requirement is SS 321 or the higher-carbon SS 321H grade.
Technical Specifications of SS 321 / 321H Instrumentation Tube Fittings
- Product : SS 321 / 321H Instrumentation Tube Fittings
- Material Grades : Stainless Steel 321 and Stainless Steel 321H
- UNS Designations : UNS S32100 for SS 321 and UNS S32109 for SS 321H
- European Designation : EN 1.4541 for SS 321
- Material Type : Titanium-stabilised austenitic stainless steel
- Imperial Tube Sizes : 1/16 inch to 1½ inch
- Metric Tube Sizes : 1.5 mm to 38.1 mm
- Thread Types : NPT, BSPT, BSPP, SAE, UNF and Metric Threads
Applications of SS 321 / 321H Instrumentation Tube Fittings
SS 321 / 321H Instrumentation Tube Fittings are mainly used in welded instrument lines and equipment exposed to elevated temperatures.
Typical applications include:
- Furnace pressure and temperature instrument lines
- Refinery fired-heater monitoring connections
- Petrochemical cracking-furnace instrumentation
- Heat exchanger gauge and transmitter hook-ups
- Hot-gas sampling systems
- Exhaust-gas monitoring lines
- Thermal oxidiser instrument connections
- Annealing and heat-treatment furnace lines
- Burner and combustion-monitoring systems
- Valve and manifold connections near heated equipment
- Heated process-skid instrumentation
- High-temperature welded equipment connections
Arrotop supplies SS 321 and SS 321H connectors, elbows, tees, unions, bulkhead fittings, reducers, adapters and ferrules for new equipment, maintenance and replacement requirements.
Instrument Connections for Refinery Heaters and Petrochemical Equipment
Refinery and petrochemical equipment uses instrument tubing for measuring pressure, temperature, flow and process conditions around heaters, cracking units, heat exchangers and hydro-treating systems.
Arrotop supplies SS 321/321H fittings for:
- Fired-heater pressure connections
- Hydro-treating unit instrument lines
- Sulphurisation equipment
- Cracking-furnace monitoring lines
- Heat exchanger gauge connections
- Hot process sampling systems
- Valve and manifold tubing
- Burner and combustion-monitoring equipment
- Furnace inlet and outlet instrumentation
- Maintenance replacement requirements
SS 321/321H is used for furnace tubes, heat exchangers and piping in chemical and petrochemical plants, including sulphurisation and hydro-treating equipment.
For a quotation, share the equipment details, fitting type, tube size, operating temperature, pressure and quantity.
SS 321 Tube Fittings for Exhaust and Thermal Equipment
Exhaust systems and thermal-processing equipment often use small-bore tubing for pressure monitoring, gas sampling and temperature-related instruments.
Arrotop manufactures SS 321 Tube Fittings for exhaust and thermal equipment, including:
- Exhaust gas sampling connections
- Stack and chimney monitoring lines
- Expansion-bellows instrument connections
- Automotive and industrial exhaust equipment
- Annealing furnace instrumentation
- Heat-treatment furnace lines
- Welded pressure-vessel connections
- Hot-air and combustion systems
- Burner control and monitoring lines
- Thermal process skids
SS 321 is commonly used for exhaust systems, expansion joints, annealing equipment, welded pressure vessels, valves and flanges.
These fittings are intended for instrument and sampling connections around the equipment. The pressure and temperature capability of the completed assembly depends on the fitting design, tubing and end connection.
Custom and Replacement SS 321 / 321H Tube Fittings
Older furnaces, imported process equipment and custom thermal skids may use tube fittings that are no longer available in standard catalogue dimensions.
Arrotop manufactures custom and replacement SS 321 / 321H Instrumentation Tube Fittings from equipment drawings, dimensional sketches or unused samples.
Custom requirements may include:
- Metric-to-imperial adapters
- NPT-to-BSP connections
- Special reducing connectors
- Extended male connectors
- Extended female connectors
- Custom bulkhead fittings
- Long-thread adapters
- Gauge and transmitter adapters
- Weld-end connectors
- Special reducer port connectors
- Non-standard body dimensions
- Repeat fittings for OEM equipment
- Replacements for discontinued fittings
For replacement requirements, share the tube OD, thread type, overall dimensions, material grade, equipment details and required quantity.
A clear photograph can help identify the product, but a drawing or physical sample is recommended when the thread or internal ferrule arrangement is not known.
SS 321 / 321H Tube Sizes, Threads and Connections
SS 321 and SS 321H Instrumentation Tube Fittings can be manufactured for imperial and metric tubing, subject to product type and fitting design.
Available options include:
- Imperial tube sizes from 1/16 inch to 1½ inch
- Metric tube sizes from 1.5 mm to 38.1 mm
- Tube-to-tube connections
- Tube-to-male thread connections
- Tube-to-female-thread connections
- Equal and reducing connections
- Bulkhead connections
- NPT threads
- BSPT threads
- BSPP threads
- SAE and UNF threads
- Metric threads
- Mixed-thread adapters
- Connections made against drawings
Mention the tube outside diameter, wall thickness, thread standard and thread size in the enquiry. The working pressure cannot be stated as one common figure for every fitting. It depends on the fitting construction, tube OD, wall thickness, tubing condition, operating temperature and end connection.
SS 321 vs SS 316L Instrumentation Tube Fittings for Heated Systems
SS 321 and SS 316L Instrumentation Tube Fittings are used for different operating conditions. SS 316L is commonly selected for process lines where corrosion resistance is the main requirement. SS 321 contains titanium and is generally specified for welded equipment and instrument tubing that remains exposed to elevated temperatures.
For furnace equipment, refinery heaters, hot-gas sampling lines and thermal-processing systems, the equipment drawing may call for SS 321 fittings for heated instrumentation systems. SS 321 is also identified as UNS S32100 and EN 1.4541.
SS 316L should not automatically be replaced with SS 321. SS 321 is not simply a higher grade of SS 316L, and it does not provide the same advantage in every chemical or chloride-bearing environment. The correct material depends on the process fluid, temperature, pressure, tubing grade and original equipment specification.
Arrotop supplies SS 321 Instrumentation Tube Fittings for welded equipment, including connectors, elbows, tees, unions, bulkhead fittings, adapters and ferrules. Share the drawing or material requirement when comparing SS 321 vs SS 316L tube fittings for an existing system.
SS 321 / 321H Fitting Packages for Furnace Shutdowns and Refinery Maintenance
Furnace shutdowns and refinery maintenance work usually require several fitting types for different instrument lines. Instead of purchasing each item separately, buyers can send one fitting schedule covering the required connectors, elbows, tees, unions, ferrules, reducers and adapters.
Arrotop supplies SS 321 and SS 321H fitting packages for furnace shutdowns, fired-heater maintenance, heat exchanger repairs and hot-process equipment overhauls.
A shutdown package may include:
- Male and female connectors
- Male and female elbows
- Run tees and branch tees
- Straight and reducing unions
- Bulkhead connectors and unions
- Front and back ferrules
- NPT, BSPT and
- BSPP adapters
- Reducer port connectors
- Tube caps and plugs
- Custom replacement fittings
SS 321H, identified as UNS S32109, is commonly used for furnace and other high-temperature equipment where the higher-temperature grade is specified.
For SS 321H fittings for refinery maintenance, share the bill of materials, tube size, thread details, required grade, quantity, material certificates and delivery schedule. Old fittings, marked-up drawings or unused samples can also be checked for replacement requirements.
SS 321H Compression Fittings for OEM Furnace and Heater Manufacturers
Furnace, heater and thermal-equipment manufacturers require tube fittings for pressure instruments, burner controls, temperature-monitoring systems, hot-gas sampling lines and valve or manifold connections.
Arrotop manufactures SS 321H Compression Fittings for OEM furnace and heater manufacturers against fitting schedules, equipment drawings and repeat part numbers.
The product range includes:
- SS 321H male and female connectors
- SS 321H compression elbows
- Run tees and branch tees
- Straight and reducing unions
- Bulkhead fittings
- Gauge and transmitter adapters
- Burner-control tubing connections
- Custom NPT and BSP adapters
- Extended-body connectors
- Drawing-based replacement fittings
SS 321H is used for furnace equipment and high-temperature components, while UNS S32109 tubing is also used in boiler superheater and reheater applications.
OEM requirements may involve non-standard thread lengths, special body dimensions, metric-to-imperial connections or fittings carrying the equipment manufacturer’s part number. Arrotop can manufacture standard and custom UNS S32109 tube fittings for heater equipment in small or repeat production quantities.
Share the tube OD, wall thickness, fitting type, thread standard, drawing, quantity and material certificate requirements for quotation.
Request a Quote for SS 321 / 321H Instrumentation Tube Fittings
Arrotop supplies SS 321 and SS 321H Instrumentation Tube Fittings for furnace equipment, refinery heaters, petrochemical units, heat exchangers, exhaust systems, thermal-processing plants and welded instrument lines. For a quotation, share the required fitting type, SS 321 or SS 321H grade, tube OD and wall thickness, thread type and size, operating pressure and temperature, process medium, quantity, drawing or sample, material certificate requirements and delivery schedule. Arrotop manufactures and exports standard, custom and replacement UNS S32100 and UNS S32109 ferrule tube fittings from Mumbai, India, for domestic and international requirements.