DO I REALLY NEED A TRUE CONTROL VALVE?

DO I REALLY NEED A TRUE CONTROL VALVE?

In many cases, the question is, “Do you really need a true control valve?”  When designing an applicationto regulate theprocess. This control application may vary in conductivity, temperature, pressure, flow and pH. For this reason, traditional wisdom, you need a good control valve for your piping solution. In this content we suggest generally a variety of different glove type of control valves. Usually made with very precise diaphragm or piston actuator. Typically, these actuators are connected to a linear ball valve, which embodies the traditional model of a true control valve. However, in many cases, Mainly because of the possibility of having this traditional glove type valve, to replace the valve solution, they think it is useless to implement. Since there are different project controls that require valves and piping, we will present some simple examples with a variety of requirements and performance to provide cost-effective solutions.Kp-LOK tubing valves and fittings

Simple flow control scheme

In a basic flow control application, the digital display in the base flow valve with installed digital and hand style can be used manually. This simple and subtle arrangement requires manual operation downstream of the installed digital flowmeter (DFM) valve. You can see that this collection looks shabby, but it is reasonable and valid in static conditions. However, if the inlet pressure and back pressure on the downstream side of the valve are heavily modified, this setting is considered an invalid and polished alternative.

Second solution to why you should use a valve

The next step in sequence control is to perform a flow meter by using a 4-20 mA signal to a programmable logic controller (PLC) or a distributed control system (DCS). Program the PLC or DCS at a predetermined rate. The PLC or the DCS sends a signal to the quarter turn device, for example with a rack and pinion drive and an electro-pneumatic V-position pneumatic ball valve. This problem-checking method provides a better solution than the “simple flow control solution” described above. Indeed, it is possible to manage different inputs and counterpressures. The middle layer of the flow control devices 10 to 15: because it does not only have a coverage ratio, these differences, or fast pressure connections, never vibrate or are too fast. (Note: the ratio of the maximum capacity defined as the minimum capacity ratio is the ratio of the valve or the working range of the device) 10-15: 1 setting, 30 °, 60 ° is selected, the degree of the ball. Indeed, the wide opening ratio can be reduced by the valve. This approach provides an affordable flow control solution and an effective “middle way”.

True control and real flexibility

The real control valve consists of a ball valve (or piston) with an electro-pneumatic positioner. Manufacturers supply these glove valves with different decorative features. Among them, linear and equivalent pruning is the most popular. In general, the same percentage balancing characteristics are obtained when a high precision downshift ratio is required at the lower end of the flow zone and the valve requires a wide range of inlet pressure and outlet pressure. Instead, in general, linear adjustment features are introduced for flow control when the process variable remains relatively constant and the valve must operate with similar accuracy over its operating flow range.

DO I REALLY NEED A TRUE CONTROL VALVE?

This valve provides the best flow control or range setting over previous solutions. This typical flow control loop consists of a flowmeter (various types) that can send an output signal of 4 to 20 mA to the PLC or DCS. The PLC or DCS provides a 4-20 mA signal to the linear glove valve, which is adjusted to maintain precise flow control on the pressure side of the valve. This configuration is usually the most expensive, but especially when exposed to different input pressures and back pressures, it is the most accurate. However, as with all valves, this installation capability is limited, and even with this final layout, the process can still be disputed. Yes, this valve can correspond to a 100: 1 reduction ratio. However, it has a limited response and response to sudden changes in process conditions. For this reason, each valve technician will ask various questions about the expected performance of a given control valve loop.

The control valve solution that is best for your application?

In the early stages of valve specification processing, a significant area must be considered, i.e. the time required to search for the real conditions of the control valve process and to evaluate the accuracy required for the control. We can show the control valve shown in the piping and equipment diagram and asks “How much control is needed and what conditions must be provided for the valve?” In many cases, such as the automatic ball valve one of the corner appliance solutions can offer enough versatility and accuracy for the application.