Control flow and pressure with AVK Needle Valves

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16 February 2022
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AVK Needle valves enable engineers to finely control and regulate water flow and pressure. The innovative AVK design for flow optimization ensures a reduced pressure loss.

The precision is achieved through the fine movement of the shaft, which enables the gearbox to move the piston tube in sliding motion towards opening or closing position, depending on the requirements from the control system.

AVK has a wide range of needle valves made from high-quality materials. Needle valves, sometimes referred to as plunger valves, can be used with high differential pressure. The AVK needle valves are available in sizes DN80 to DN2000 in PN10, 16, 25, 40, 64 and 100. Our needle valves are therefore also recommended for regulation in large diameter pipes and at high pressures.

When to use needle valves?
•Flow control
•Pressure regulation
•Pump start
•Turbine by-pass
•Reservoir inlets
•Air regulation

The needle valves can be manually actuated or can be controlled by electrical, hydraulic or pneumatic actuation.

Main features and benefits
•One-piece body construction
•Stainless steel internal parts and fasteners for a long life of the valve
•All ductile iron parts coated with min. 250 µm fusion bonded epoxy
•Shaft sealing with double O-rings
•Main seal in the no-flow zone at the valve outlet
•4-6 guide rails ensure very low vibration
•Gaskets in thermoplastic PUR for high resistance to abrasion
•Pressure balance in chamber inside for low operating torque
•Symmetric flow path with annular flow cross section in any open position
•Internal body shape is optimized to give a low head loss in fully open position

State-of-the-art design
AVK needle valves are straight-way type control valves and are designed with a one-piece body construction and an. Our needle valves require very low operating torques, as the piston is always in hydraulic balance with equal force on both sides at all valve positions. This feature facilitates the operations of all actuators and significantly reduces actuator and gearbox costs.

High quality and long lifetime
Our needle valves have a long lifetime due to all internal and moving parts in stainless steel and the body is completely protected by fusion bonded epoxy coating. Also, the sealings make up a long-life system and high-performance seal, located in no-flow zone, is easily replaceable without disassembling the valve from the pipeline. The needle valves are equipped with a special and innovative gasket for a perfect and bidirectional seat. All gaskets are located safely in the no-flow zone. In addition, the compact piston has 4-6 replaceable bronze guides to ensure very low vibration.

Strict quality control is performed on all AVK needle valves using static and dynamic test benches. Quality parameters are carefully checked by our highly qualified personnel.

Dedicated software for accurate size calculation
Each valve is set according to relevant selection criteria for its specific application. Therefore it is necessary to provide the necessary information concerning hydraulic data (flow and pressure), installation design and requested operation when placing an order or quotation. This ensures that the needle valve has an optimum performance for the requested installation. Using our special sizing calculation software, a fluid and cavitation report can be provided under the requested hydraulic conditions. The report guarantees a cavitation free valve.

AVK has made a selection of optional extras for actuation and cavitation prevention. The current operating data is entered per valve, after which the valve operates without cavitation, even at major pressure differences.

Upon request we can provide needle valve solutions for custom designed control configurations:
•Worm gear box and handwheel
•Electric actuator
•Hydraulic brake and lift unit
•Double acting hydraulic piston
•Simple acting hydraulic piston
•Double or single acting pneumatic actuator

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AVK Industrial Nederland BV