Features of Valfonta Pneumatic Control Valves
In manufacturing plants, it is often necessary to use compressed air control to obtain and maintain the required parameters for steam, gas or liquids. For example, due to the location in remote points of production, where it is difficult to provide a reliable power supply, as well as in places where it is forbidden to use standard electric actuators according to explosion hazard rules, or it is not possible to protect the actuator from exposure to liquids in the event of an accident, or high response is required when regulating the temperature in technological process. In these cases, pneumatically actuated temperature and pressure regulators are used.
OPEKS ENERGOSYSTEMY successfully solves similar production problems with the help of the VALFONTA range of valves manufactured in Spain. The equipment of the VALFONTA company has established itself as reliable and high quality, and the use of these valves together with the electro-pneumatic positioner in the processes of temperature and pressure control in many enterprises has confirmed in practice the high accuracy of maintaining the set parameters (temperature, pressure).
The body of the VALFONTA C1 control valve can be made of the following materials:
- ductile iron GJS-400-18-LT (0.7043);
- bronze RG-10 (EN-1982 CuSn10-CC480K);
- carbon steel GP240GHN (1.0619);
- stainless steel CF8M (1.4408).
The ability to use a wide variety of materials allows the valves to be used in a variety of technological processes and industries, such as pharmaceutical and chemical plants, refineries, food processing and many others.
Installation of control valves can be carried out both on horizontal and on vertical sections of pipelines, with the actuator located up or down relative to the valve. Also, having in the arsenal different designs of protective caps and stem materials, the valves can be used to regulate media with temperatures up to +350 ºC. Valve working pressure class: PN25, PN40. All valves are supplied as standard with a flange connection and a B1 face (according to EN1092-1). On an individual basis, it is possible to supply valves with BSP or NPT, BW, SW threaded connections.
Control can be proportional, proportional integral or open / closed. The design of the valve actuator allows for easy reversal of the direction of the actuator (normally open or normally closed) without removing the valve from the pipeline. The valve actuator regulates the parameters of the media with high precision, and the diaphragm allows the pneumatic actuator to operate in the range from 1.2 to 4.2 bar overpressure, which is created by the control compressed air.
The main characteristics of the pneumatic actuator model C1:
- Body - steel 1.0335 with epoxy coating;
- EPDM diaphragm + mesh reinforced (NBR on request). Working temperature from -20ºC to +70 ºC;
- Permissible overpressure of air up to 4.2 bar (1/4 ”BSP-F connection);
- 4 types of actuator depending on the adjustable pressure range: AP230, AP295, AP350 and AP430;
It is possible to expand the functionality of the control valve due to the following additional options: electro-pneumatic positioner 4-20 mA, air filter, manual wheel mounted on the top of the pneumatic actuator, all-stainless steel construction of all elements, solenoid valve, emergency position sensors and others.
VALFONTA manufactures control valves in the range of diameters DN15 - DN100 (up to DN150 on request). With these valve diameters, the K v is between 3.5 and 130 m3 / h.
The principle of operation of a valve with a positioner is to maintain a consistent stem position relative to the control pressure. By installing the positioner on the control valve, the mismatch between the command air pressure and the position of the stem, which can form due to natural frictional forces during the movement of the stem and plunger, is also removed, it becomes possible to organize accurate feedback and automate the regulation process, provide for the possibility of dispatching.
One of the main advantages of Valfonta pneumatically actuated valves is their competitive cost and high quality workmanship compared to similar products from other manufacturers.