stvvalves

  There are many different   types of valves   available for different applications. With so much choice it can be difficult to decide which valve is most suitable for your application. In this article, STV Supplies explores the merits of ball valves versus globe valves. WHAT IS THE MAIN DIFFERENCE BETWEEN BALL AND GLOBE VALVES? The main difference between ball and globe valves is the way they close. Ball valves have a stem and ball, which turns horizontally, and are commonly referred to as “rotational” valves. Whereas, globe valves have a stem and plug, which strokes linearly, and gives them their other name of “stroke” valves. Ball valves are best suited to applications requiring on/off control without pressure drop. While globe valves excel at regulating flow. HOW DOES A BALL VALVE WORK? Ball valves are designed with a ball inside the valve. A ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball (called a “floating ball”) to cont...

  Ball Valves A valve is a device that controls, regulates, or directs the flow of a fluid, by closing, opening, or partially obstructing one or more passageways. Ball valves are a type of quarter turn valve that controls flow. They serve as more effective alternatives to similar valves, like butterfly valves and gate valves.  Note that ball valves are not the same thing as “ball check valves.” While the two have similar names, ball check valves are designed differently and serve a different purpose. Applications The goal of ball valves is to regulate fluid flow. They can do so in a number of ways. They can regulate some types of low flow valves, provide backflow prevention for valves with a swing check component, isolate systems, and provide gear operators with complete shut-off capabilities. Because they are available with either manual or motorized controls, ball valves can provide their services to applications in a wide variety of settings. Mostly, ball valves are used fo...

  Check valves play a critical role in preventing backflow and protecting sensitive equipment, pipes, pumps, and compressors. However, check valves can’t function at their best if they aren’t installed properly. Mistakes in installation can manifest in valve leakage or failure, compromising the integrity of the entire piping system.  Swing check valves, double-door check valve, or silent spring-assisted axial flow check valves, all control flow through a slightly different mechanism. Swing valves use a disc that swings in and out of the fluid stream while double-door valves use springs to close two “doors” to stop the flow. Spring-assisted axial flow valves use a disc and stem design and incorporate compression springs to close the valve before the fluid flow has reversed its flow direction. This is important because the quick closing nature of the axial flow design drastically reduces the possibility for water hammer—a dangerous malfunction where sudden pump shut down or an a...

  Check valves   prevent backflow in a piping system. Also known as   non-return valves   or NRV, these mechanisms ensure that the valve closes if the fluid flow passing through the pipe reverses. Ensuring unobstructed flow, a check valve can automatically close when pressure decreases. They are found in many industries with applications in mining, natural gas, and water. Check valve purchases typically take into consideration line size, pressure class, working pressure, flow rate, and media gravity and temperature. Some of the most common types of check valve include: Ball Double Door Lift Piston Stop Check Swing Tilting Disc Read more about the different varieties of check valve types below. Ball Check Valves The Ball Check Valve replaces the disk device often used to prevent flow with a ball that relies on gravity. Under pressure from the flow, the ball will lift up out of the pipe outlet. When low pressure lessens sufficiently, the ball falls back into ...

  Valves are an essential part of any piping system in the oil and gas industry. Valves help regulate the flow of materials to and from machinery and equipment. This makes them integral in the many different kinds of functions and applications. Valves in the oil and gas industry have to work with liquids, gasses, viscous materials, and corrosive mediums.  At any given time, a single factory may have a number of different kinds of valves installed, each performing a different function. Valves in oil and gas factories can be used to start and stop the flow. Some valves can also be used to regulate the flow according to the pressure and velocity requirements. This article features a list of common valves used in the oil and gas industry, along with their function, pros, and cons.  What Types of Valves are Used in the Oil and Gas Industry? There are a number of different processes that take place inside and oil and gas factory. Each of those processes requires different kinds...

Trim of Valves THE REMOVABLE AND REPLACEABLE VALVE INTERNAL PARTS  that come in contact with the flow medium are collectively termed as  VALVE TRIM . These parts include valve seat(s), disc, glands, spacers, guides, bushings, and internal springs. The valve body, bonnet, packing, et cetera that also come in contact with the flow medium are not considered valve trim. A Valve's trim performance is determined by the disk and seat interface and the relation of the disk position to the seat. Because of the trim, basic motions and flow control are possible. In rotational motion trim designs, the disk slides closely past the seat to produce a change in flow opening. In linear motion trim designs, the disk lifts perpendicularly away from the seat so that an annular orifice appears. Valve trim parts may be constructed of assorted materials because of the different properties needed to withstand different forces and conditions. Bushings and packing glands do not experience the same forc...