Needle valves are extremely important to applications where precise adjustments of flow are necessary. They can protect delicate instrumentation from sudden surges of media by controlling flow and are perfect for processes where a small flow rate is desired. In this article, we will be answering the question ‘what does a needle valve do’ and discussing the various high-quality needle valves available from Fluid Controls.
The needle valve is akin to most other valves in the fact that it is responsible for the safe and effectual operation of industrial equipment and processes. The construction of a needle valve enables it to effectively control the rate of flow within a pipeline. In some cases, needle valves are imperative to a system, as they protect delicate equipment such as gauges. The main function of a needle valve is to safeguard equipment from potential surges of media that occur under vast amounts of pressure, relieving the risk of damaging equipment and processes.
The construction of a typical needle valve includes a tapered pin that gradually opens a space for fine control of flow. This flow is then controlled and regulated with a spindle. A needle valve has a relatively small orifice with a long, tapered seat, and a needle-shaped plunger on the end of a screw which fits the seat exactly. As the screw is turned and the plunger is retracted, flow between the seat and the plunger is possible. However, until the plunger is completely retracted, the fluid flow is significantly impeded.
Here at Fluid Controls, we supply a vast range of high-performance needle valves, all of which are from the Parker catalogue of products. Below are just some of the top-quality needle valves that are available at Fluid Controls.
Parker’s PV Series of rising plug and gauge/root valves have a screwed bonnet design with bonnet lock plates and are available with a variety of seat and seal materials. These needle valves provide a straight through flow path in two orifice sizes, utilising a non-wetted upper stem and a non-rotating lower stem in conjunction with a tapered seat for positive shut-off and long seat life, even in high particulate media.
Parker NP6 needle valves are designed with packing below the stem threads and a two-piece stem. The packing below the threads protects the flow stream from thread lubricant contamination or washout, and also protects the stem threads from potentially damaging effects to the media. The two-piece stem produces a non-rotating lower stem for superior, repeatable sealing and reduced packing wear.
Parker V Series needle valve specifications allow for a leak tight shut-off and regulation of fluids in process, power and instrumentation applications. With a wide variety of port sizes and styles, temperature capabilities ranging from -54 °C to 232 °C (-65 °F to 450 °F) and pressures to 345 bar (5000 psig), V Series needle valves provide the utmost in flexibility when designing miniaturised tubing or piping systems.
For more information on the function of a needle valve or to discuss needle valve specifications for your application, contact us today on 0118 970 2060 or email fluid@fluidcontrols.co.uk for more information.