Incoloy is from the family of super alloys. Incoloy alloys have a nickel-iron-chromium composition that provides good strength and resistance to carburization and oxidation when exposed to high temperatures. Thus, it is used to make various products. In this blog, we will learn more about one such Incoloy product i.e. Incoloy 825 needle valve.
WHAT IS INCOLOY 825?
It is nearly identical to alloy 800 but has better aqueous corrosion resistance. From cryogenic to medium-high temperatures (5400C), it has good mechanical properties and can be significantly strengthened by cold working. The important alloying elements in Incoloy are nickel (38%-46%), iron and chromium (19.5%-23.5%) but in Incoloy 825 Needle valves there are additions of molybdenum, copper and titanium which add to the advantages of Incoloy 825.
Molybdenum (2.5%-3.5%): Improves hardenability and strength at elevated temperatures
Copper (1.5%-3.0%): Enhances chemical properties by increasing resistance against corrosion.
Titanium (0.6%-1.2%): Adds to the strength and resistance to corrosion and also provides lightness to the steel as it’s density is less than half that of steel.
WHAT IS INCOLOY 825 NEEDLE VALVE?
Valves are devices that control the flow and pressure within a system or process. A Needle valve is a type of valve that is used to precisely control the flow rate of clean gases or fluids. It features a sharp-pointed ‘needle-shaped’ plunger and a small port which gives them their name. The austenitic steel Alloy 825 Needle Valves has excellent corrosion resistance, strength, and improved general and localized corrosion.
- Construction of Needle Valve: In a pipeline, needle valves are used to start, stop, and regulate the flow rate. They have a long, tapered needle-like point at the valve stem’s end (i.e. plunger). The position of the plunger is also controlled by a hand wheel or a small handle located on the plunger in these valves. The plunger of the valve fits into the seat. A needle valve’s unique design allows it to precisely and accurately control the amount of fluid that passes through it.
APPLICATIONS OF INCOLOY 825 NEEDLE VALVE
- They are suitable for use on gas bleeder lines.
- Hydraulic & pneumatic power systems.
- Used in flow metering systems.
- In automatic combustion control systems that require precise flow regulation.
- Used in constant pressure pump governors to decrease the impacts of pump discharge pressure fluctuations.
ADVANTAGES OF NEEDLE VALVES
- Accurate flow control.
- Requires less space (smaller in size).
- Suitable for throttling purposes.
- In water heating systems, they’re used as bleed valves.
- It is easy to turn on and off.
DISADVANTAGES OF NEEDLE VALVES
- Substantial pressure loss due to high restriction of fluid flow.
- Can be used mostly for low flow rates as the passage flow between the seat and needle is small.
- The needle can be easily damaged if the fluids have floating solids.
- Can’t easily make out the position of the valve by examining the handle position.
- Due to excessive turning force the needle can be damaged while shutting off the seat.