Stainless seamless precision tubing is used in Instrumentation and hydraulic systems, which is manufactured to conform to ASTM A269 standard, standard sizes contain 3/8”, 1/4“, 1/2″, and 3/4″ in outside diameter and 0.028″, 0.035″, 0.049″, 0.065″ in wall thickness. ASTM A269 Instrumentation tubing finished in smooth bright annealed surfaces and with strict requirements for deviation in diameter and wall thickness to reduce the risk of leakages when connecting tubes with single or twin ferrule couplings.
Instrumentation tubes are stainless, duplex, nickel tubes with mostly relatively thinner walls. The majority of diameter for instrumentation tubing varies within 1.5 mm OD to 60 mm OD. on random lengths of 6 meters or coils up to 1000 meters long without welds.
Instrumentation Tubes are important components in hydraulic and instrumentation systems to protect and partner with other components, devices or instruments to secure the safe and trouble-free operations of oil and gas plants, petrochemical processing, power generation and other critical industrial applications.
Stainless Steel and Nickel alloy Instrumentation Tubing Specifications
The standard tolerances specifications for stainless steel are according to ASTM A 269/A 213/A 632 & EN 10216-5 TC1, ISO 1127 D4/T3. For duplex, nickel & titanium alloys are according to ASTM A 789/B 163/B 165/B 407/B 423/B 444/B 622/B 677 & B338.
Instrumentation Tubing Sizes And Dimensions
Stainless steel Instrument tubing comes in a wide variety of sizes, Outside diameter ranges from 0.125″ to 2″, and 0.012 to 0.25 inch in wall thickness, tubing length can be straight, also in coil, short lengths can be cut for structural purposes, and they are bendable when required, inch sizes are following.
- Outside diameter: 1/8″, 1/4″, 3/8″, 1/2″, 3/4″ (3.18, 6.35, 9.53, 12.7, 19.05 mm)
- Wall thickness: 0.028″, 0.035″, 0.049″, 0.065″ (0.71, 0.89, 1.24, 1.65 mm)
Stainless Steel Grades
Tubes are produced in accordance with either customer-specific specifications or an internal specification that meets the industry standards for 300 series austenitic stainless steel. Final applications for medium and high-pressure tubes are where higher strength and corrosion resistance are important.
The chemical composition of the material must conform to current ASTM A213-A269 specifications for the following grades: Type 304/304L and 316/316L (Type 317/317L to ASTM A213 only)
- TP304, UNS S30400, ASTM A269
- 304L, UNS S30403, ASTM A269
- TP316L, UNS S31603, ASTM A269
- TP321, UNS S32100, ASTM A269
- UNS S31803/S32205, ASTM A789
- 904L, UNS N08904, ASTM A269
- 254 SMO, UNS S31254, ASTM A213
Conditions And Surface
Commonly, hydraulic instrumentation tubing is annealed to conform to standard solution temperature, then has a pickling passivated surface, deburring tubing ends to insert in fittings.
The tubing surface should be free of scale and clean. In some cases, to achieve a higher clean and smooth surface, bright annealing is required, both in seamless tubing and welded tubing.
Tolerance And Accuracy
The tubes we manufacture and deliver for hydraulic and instrumentation systems are noted for their quality and low lifecycle costs. Hydraulic instrumentation tubing should be of consistent quality, high corrosion resistance, high surface smoothness and close dimensional tolerances reducing the risk of leakages and ovality, eccentricity and controlled hardness required for superior performance. When tubing is bent, tolerances are controlled strictly to connect pipe fittings tightly.
Hydraulic and instrumentation tubing are tested according to the standards as follows.
| Standard | Tests Chemical Analysis | Tensile | Hardness | Flattening | Flaring | Corrosion | Hydrostatic |
|---|---|---|---|---|---|---|---|
| EN 10216-5 TC1 | S | S | – | S | S 1) | – | T |
| ASTM A269 | S | – | S | – | S | – | T |
| ASTM A213 | S | S | S | S | S | – | T |
| ASTM A789 | S | S | S | – | S | – | T |
| ASTM B668 | S | S | – | – | S | – | T |
| ASTM A632 | S | S | – | – | S | – | T |