Needle Valves

What is a needle valve?

First of all, lets know about the basics of a needle valve. It comprises of a tapered pin which is used to slowly open some space so that the flow can continue in a fine manner. This flow can be regulated and controlled by the help of a spindle.

Working and operation of needle valves

The working of needle valve is basically for the efficient and secure operation of industrial machines. Their function is to control the fluid flow rate happening inside a pipeline. They can either work automatically or manually.

  • In manual needle valves, there is a handwheel that controls the distance between seat and plunger. In one direction of handwheel, the plunger opens the valve and thus fluid starts flowing. In other direction of handwheel, the plunger will close the valve and reduce the flow rate.
  • In the automatic needle valves, they are connected with an air actuator or a hydraulic motor which can produce an automated response for closing or opening the needle valve. The position of plunger will be adjusted by actuator or motor based on the external performance data and timers (data gathered while monitoring the machines).
    Both the manual and automated needle valves have the ability to provide accurate flow rates.

Function of Needle valves

The needle valves are used in a live process plant. Between a block and bleed function, the needle valves are used so that the maintenance operations can attain positive isolation. Needle valves work perfect in a low- pressure system or with the non- hazardous fluids and any other non- critical processes. The plunger inside the valve is shaped like a needle and is a threaded small port. It allows the accurate regulation of flow in applications where flow rate is lesser. The needle valves work perfectly in the applications involving flow- metering. Moreover, they are also vital in maintaining a regulated and consistent flow rate.

Types of Needle Valves

The needle valve manufacturers design them in a wide range of sizes. The size ranges are 1/8’’,3/8’’, 1/4’’, 3/4’’, 1 inch,8mm. The stem tips of these valves are also of different types like the soft seat, v- stem or the regulating ones which work very well for various applications that involve the pneumatic and hydraulic systems. The material used in manufacturing needle valves is always a high quality 316 stainless steel and the alloy 400. The needle valves are designed exactly for the required system compatible perfectly with the temperature and flow.

Kp-Lok offers different types of needle valves mentioned as follows:

  • NVFF Series Integral Bonnet Needle Valves

  • These needle valves have a usual temperature rating of -65o F to 450o F and a pressure rating up to 5000 psi. The integral bonnet needle valves have one-piece body and are generally available with both angled and straight patterns. Easy mounting standard is gained by the panel mounting nut.

  • NVMF Series Bar Stock Needle Valves

  • These needle valves are available in various materials and pressure rating up to 10000 psi. They can be adjusted externally, have wear compensation and absolutely unique stem packing. These properties render the screwed bonnet needle valves to offer worry- free service life in most of their gaseous and liquid applications.

  • 90- degree needle valve(angle needle valve)

  • They are used to make sure that fluid turns to 90 degrees after passing through the valve and then passes through the orifice acting as seat. There is a rod with the seat and the tip of this road is shaped like a cone. These valves are basically used to manage the real gaseous and liquid flows.

  • NVFF Series High Pressure Needle Valve

  • The Kp-lok high pressure needle valve is engineered to handle heavy duty use in tough conditions. This high pressure needle valve boasts a premium quality bonnet and stem with a superior packing arrangement. The valves are manufactured for manual operation in varying temperatures. Rugged construction ensures fail-safe operation under extreme pressures.

  • NVFF Series Double Block and Bleed Needle valve

  • The Double Block and Bleed needle valve serve you efficiently and save space to eliminate the need for complicated and multi-valve systems. The Kp-lok double block and bleed valves are designed to sustain pressures up to 20,000 PSI at 72°F. It is primarily constructed out of 316 stainless steel, but these the valves can be produced from other machine-able alloys to meet specific requirements.

  • Other types

  • There are other types of needle valves too that comprise of high pressure,high temperature, double block and bleed needle valve and many others.

    Needle valve composition

    The needle valve contains the male and female NPT in the end connection, some tube fittings and the ISO threads which range from 1/8‘’ to 1’’. The end connection is available in the carbon steel, stainless steel, alloy 400 and brass. The temperatures that needle valve needs to withstand is almost 1200o F and the pressure rating can go up to as much as 10,000 psi. The needle valve solution can surely fix the problem out of your system. The needle valves are generally made up of bronze, brass, alloy 400 and stainless steel.

    Applications of needle valves

    Basically, the purpose of needle valves is to control the flow rate and prevent any sort of damage happening to the delicate gauges due to sudden pressure surges of gases and liquids. Needle valves find applications in the systems that employ less viscous and light in weight materials having lesser flow rates. The needle valves can be applied to oxygen and high temperature service depending on materials used.

    They are used in

    • Chemical processing
    • Low pressure hydraulic systems
    • Other liquid and gas services

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