KSPKNOWLEDGE SHARING PROGRAM

Topic- INSTRUMENT IMPULSE PIPING & TUBING

-:by:- Mohammad Zulfequar Ali Khan

Dy. Manager -Quality E&I(3.0 MTPA Blast Furnace Project, Nagarnar)

In Process industries the connection between Process piping and Field transmitter is done by either Impulse piping and Impulse tubing depending upon the nature of service.

Impulse Piping Types:- Stainless Steel Alloy Steel Carbon steel

Impulse Tubing Types:- Stainless Steel

IMPULSE PIPING & TUBING

Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, sulphur and oxygen.

There are more than 3,500 different grades of steel with many different physical, chemical, and environmental properties.

If the Eiffel Tower were to be rebuilt today, the engineers would only need one-third of the steel that was originally used.

Since 200 BC, many cultures have produced steel in one form or another. A British inventor, Henry Bessemer, is generally credited with the invention of the first technique to mass produce steel in the mid 1850s.

Steel is still produced using technology based on the Bessemer Process of blowing air through molten pig iron to oxidise the material and separate impurities.

Source: http://www.worldsteel.org/

STEEL- Some facts

Many elements and materials go through chemical reactions with other elements. When steel comes into contact with water and oxygen there is a chemical reaction and the steel begins to revert to its original form - iron oxide.

In most modern steel applications this problem is easily overcome by coating. Many different coating materials can be applied to steel. Paint is used to coat cars and enamel is used on refrigerators and other domestic appliances. In other cases, elements such as nickel and chromium are added to make stainless steel, which can help prevent rust.

Why does steel rust ?

COMPOSITION CAST IRON WROUGH IRON PLAIN STEEL HIGH STRENGTH

STEELSTAINLESS

STEEL

CARBON 3.50% 0.035% 1.350% 0.250% 0.080%

MANGNEESE 0.50% 0.075% 1.650% 1.650% 2.000%

PHOSPHORUS 0.13% 0.075% 0.040% 0.040% 0.040%

SULFUR 0.13% 0.100% 0.050% 0.050% 0.030%

SILICON 1.20% 0.100% 0.060% 0.120% 0.750%

NICKEL x x x 2.500% 8.000%

CROMIUM x x x 0.800% 18.000%

Steel Composition

Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12–2.0%.

"Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect

or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon0.60, copper 0.60.“

The term "carbon steel" may also be used in reference to steel which is not stainless steel.

Low carbon steel<0.3% carbon content Medium carbon steel Approximately 0.30–0.59% carbon content High-carbon steel (ASTM 304)Approximately 0.6–0.99% carbon

content. Ultra-high-carbon steel Approximately 1.0–2.0% carbon content.

CARBON STEEL

ALLOY:-A metal made by combining two or more metallic elements, especially to give greater strength or resistance to corrosion.

ALLOY STEEL:-is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. “Alloy steel" is the standard term referring to steels with other alloying elements in addition to the carbon. Common alloyants include manganese (the most common one), nickel, chromium,molybdenum, vanadium, silicon, and boron. Less common alloyants include aluminum, cobalt, copper, cerium, niobium, titanium,tungsten, tin, zinc, lead, and zirconium.

ALLOY STEEL

ALLOY STEEL GRADES & COMPOSITIONS

Grade P-5 P-9 P-11 P-22 P-91

Compositions %

Carbon 0.15 max 0.15 max 0.05 - 0.15 0.05 - 0.15 0.08 - 0.12

Manganese 0.30 - 0.60 0.30 - 0.60 0.30 - 0.60 0.30 - 0.60 0.30 - 0.60

Phosphorous, max 0.025 0.025 0.025 0.025 0.020

Sulfur, max 0.025 0.025 0.025 0.025 0.010

Silicon 0.50 max 0.25 - 1.00 0.50 - 1.00 0.50 max 0.20 -0.50

Chromium 4.00 - 6.00 8.00 - 10.00 1.00 - 1.50 1.90 - 2.60 8.00 - 9.50

Molybdenum 0.45 -0.65 0.90 - 1.10 0.44 - 0.65 0.87 - 1.13 0.85 - 1.05

stainless steel is a steel alloy with a minimum of 10.5% Chromium content by mass.

Stainless steels contain sufficient chromium to form a passive film of chromium oxide, which prevents further surface corrosion by blocking oxygen diffusion to the steel surface and blocks corrosion from spreading into the metal's internal structure.

Broadly use Stainless Steels in Process Industries are: SS:304, SS:316, SS:317, SS:321

STAINLESS STEEL

S.S. 304 304L 316 316L 317 321Carbon 0.08 0.03 0.08 0.03 0.08 0.08

Manganese 2.00 2.00 2.00 2.00 2.00 2.00

Silicone 1.00 1.00 1.00 1.00 1.00 1.00

Chromium 18/20 18/20 23/26 16/18 18/20 17/19

Nickel 8.0/12 8.0/12 10/14 10/14 11/15 9.0/12

Molybdenum     2.0/3.0 2.0/3.0 3.0/4.0  

Phosphorus 0.045 0.045 0.045 0.045 0.045 0.045

Titanium             5XC

Sulphur 0.03 0.03 0.03 0.03 0.03 0.03

SS- Chemical Compositions (Broadly use SS)

Welding is joining two pieces of metal by:◦ Heating to temperature high enough to cause softening or melting◦ With or without application of pressure

This is often done by melting the work-pieces and adding a filler material to form a pool of molten material (the weld pool) that cools to become a strong join and produce the weld.

Following are the best known welding methods: Shielded metal arc welding (SMAW) - also known as "stick welding", uses

an electrode that has flux, the protectant for the puddle, around it. The electrode holder holds the electrode as it slowly melts away. Slag protects the weld puddle from the outside world.

WELDING

Gas tungsten arc welding (GTAW) - also known as TIG (tungsten, inert gas), uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert shielding gas such as Argon or Helium.

GTAW

Gas metal arc welding (GMAW) - commonly termed MIG (metal, inert gas), uses a wire feeding gun that feeds wire at an adjustable speed and sprays an argon-based shielding gas or a mix of argon and carbon dioxide (CO2) over the weld puddle to protect it from the outside world.

GMAW

A welding joint is a point or edge where two or more pieces of metal or plastic are joined together. They are formed by welding two or more work pieces (metal or plastic) according to a particular geometry. Five types of joints referred to by the American Welding Society.

A butt weld is the most common and easiest to use. Consisting of two flat pieces that are parallel to one another. In this Bevel edge preparation is needed.

Edge welding joints, a groove type of weld, are placed side by side and welded on the same edge. They are often applied to parts of sheet metal that have edges flanging up or formed at a place where a weld must be made to join two adjacent pieces together.

Lap welding is formed when two pieces are placed atop each other while also over lapping each other for a certain distance along the edge. Considered a fillet type of a welding joint, the weld can be made on one or both sides.

A corner weld is a type of joint that is between two metal parts and is located at right angles to one another in the form of a L. As the name indicates, it is used to connect two pieces together, forming a corner. 

Tee joints considered a fillet type of weld, form when two members intersect at 90° resulting in the edges coming together in the middle of a component or plate. It may also be formed when a tube or pipe is placed on a baseplate.

WELDING JOINTS

PIPE FITTINGS Bevel edge Impulse Pipe fitting for Butt weld

Socket fitting for fillet/socket weld

IMPULSE TUBING:- The connection from process line tapping point to transmitter end can also be done through Impulse tubing. The most Common types of steel use for this piping are SS-304 and SS-316.

The dimensions are as follow:- OD for tube :

Size 6MM 12MM 20MM …… 35MM 38MM 42MM Tube Thickness :

Size 1.0MM 1.5MM 2.0MM …… 4MM 5MM 10.0MM

IMPULSE TUBE

THANKS