Cast Steel Low Pressure/Forged Steel/Bellows Sealed Globe Valve

What Are Globe Valves Used For?   Otherwise known as control valves, the role of globe valves is the regulation of flow media. In addition, globe valves have also great sealing capabilities. This also makes it a great device for sealing off water. Applications for globe valves include:Fuel oil pipeline systemsTurbine sealsHeater drain systemsTurbine lube oil systemsChemical feed systemsWater systems that need regulated flowHow Do Globe Valves Work?   Water faucets are the best example to show how globe valves work. Turning on the faucet means raising or lowering the stem, depending on the design. Water then comes out of the faucet. When turned to the other direction, say, turned off, the raised gate is lowered or the lowered gate is raised.The number of turns affects the volume of water that goes out of the faucet. Similarly, by controlling the wheel of the valve, a certain volume of gas or liquid passes through the valve. A fully turned on globe valve means the flow rate is at its maximum. On the other hand, a fully turned off globe valve means sealing of the valve.     Why Choose Globe Valves?     Good throttling capability   Can be a shut-off and on valve   More variants in terms of body design, disks and bonnet attachment styles   Can be a stop-check valveConsiderations When Buying Globe Valves   #1 Valve Size LimitationsThere is a limitation to the valve diameter because of the internal pressure of the flow media. Globe valve manufacturers limit the size to Nominal Pipe Size (NPS) 12 or Nominal Diameter (DN) 300. Beyond these ranges, when under pressure, the valves may not open or close easily. #2 Valve TrimsWhen dealing with throttling and high pressure that is beyond 200 psi, valve trims tend to fail. In situations like this, it is better to request a specialized valve trim.#3 P-T RatingP-T rating refers to the rating of the highest pressure and temperature ratio the valve can handle in relation to the metal material.As temperature increases, the capability of the body to handle pressure declines. In addition, the seat material and design determine the overall rating.Most globe valve manufacturing companies use the overall rating dictated by ANS, ie. the body pressure rating at 100°F.#4 Medium TypeThe medium type is one of the most important considerations when buying a globe valve. There are many kinds of media which may or may not be suitable for certain valve designs.For example, slurries are not suitable medium as they are heavier and contain larger components that could be left behind. These, in turn, can damage the disks. Furthermore, such viscous material can create a huge pressure drop.#5 MaterialMedium that flows in the valve correlates with the material used in making the valve. Is the material used corrosive-resistant? How concentrated is the flow material? Will it be a flowing media condition? Or is it going to stop the media from flowing? Answers to these questions directly affect the lifespan of the valve. #6 Compliance With Industry StandardsBy following and meeting industry standards, it maintains the integrity of the valve as well as provide safety assurance.These would include certifications and standards given by the following: The American Society of Mechanical Engineers (ASME) American Petroleum Institute (API) The Manufacturers Standardization Society (MSS) of Valve Fittings Industry StandardsInformationASME B16.34Valves, Flanged, Threaded and Welding EndASME B16.10Face to face and end to end valve dimensionsASME B16.11Forged Fittings, Socket Welding and ThreadedASME B16.25Butt Welding EndsASME B16.5Pipe Flanges and Flanged FittingsAPI 623Steel Globe Valves - Flanged and Butt Welding Ends, Bolted BonnetAPI 598Valve Inspection and TestingMSS SP-25Standard Marking System for Valves, Fittings, Flanges, and UnionsMSS SP-42Corrosion Resistant Gate, Globe, and Check ValvesMSS SP-61Pressure Testing of ValvesGlobe Valve Types By Body Design   There are three main body designs for globe valves. Each has unique designs suitable for particular applications.T(Tee) Pattern Globe ValveThis is the most common design. Its distinct feature is the Z-shaped diaphragm and that the seat lies horizontal and perpendicular to the stem.This position allows low flow coefficient but high-pressure loss. As a result, it is very suitable for throttling applications not concerning with the pressure drop.Angle Pattern Globe ValveThis pattern is an offshoot of the Tee Pattern. Instead of linear motion, fluid passes through the globe valve in a 90° turn. This allows for a low flow rate that is suitable for pulsating flow applications. As a result, it prevents sedimentation.Y (Wye) Pattern Globe ValveIn contrast to the previous two patterns where the stem is upright, the Y (wye) pattern has a slanted 45° stem. This type of pattern has a lower pressure drop than the previous two.When fully opened, the flow of the media is more straight, hence the low-pressure drop. The wye design, or Y style, is more common in a