A solenoid valve is a combination of two basic functional units. A solenoid (electromagnet) with its plunger (core) & a valve containing an orifice, in which a disk is positioned, either to allow or to prevent the flow of the medium being controlled. In the main, solenoid valves are covered by the following types of operation.
Direct Acting Asco Solenoid Valves
In a direct acting Asco Solenoid Valve, the solenoid plunger (core) is mechanically connected to the valve disk and directly opens or closes the orifice, depending upon whether the solenoid is energized or de-energized. Operation is independent of line pressure or rate of flow and the valve will operate from zero pressure to its maximum rated pressure.
Pilot Operated Solenoid Valves
This type of valve incorporates a pilot and bleed orifice and utilizes the line pressure for operation. When the solenoid is energized the pilot orifice is opened and pressure is released from the top of the diaphragm to the outlet side of the valve. This results in an unbalanced condition which causes the line pressure to lift the diaphragm and open the main orifice. When the solenoid is de-energized the pilot orifice is closed and full line pressure is applied to the top of the diaphragm via the bleed orifice, thereby providing a seating force to close the main orifice.
External Pilot Operated Solenoid Valve
This valve is usually of diaphragm or piston operated construction, equipped with a three-way solenoid pilot valve. The pilot valve alternatively applies pressure to or exhausts pressure from the diaphragm or piston for the operation of the main valve. Line pressure or a separate source of pressure can be utilized to operate the pilot valve. The simple two-way valves briefly described above form the majority of solenoid valves used in the industry. Other more complex types in use include three-way and four-way valves, manually and electrically reset valves and a wide variety of special valves.
Actuation Valve & Control are the leading suppliers of Asco Solenoid Valves in the UK. Asco Numatics offer a comprehensive range of fluid power, control and pneumatic solutions for a wide range of industries and applications. Many years of process expertise and experience has lead to industry-leading innovations which has, in turn, enabled Asco to offer an unrivalled amount availability, reliability and cost-effective solutions with over 50,000 Solenoid Valves within the range.
We recognise the importance of safety, reliability and availability in the automation of process valves and have positioned ourselves favourably to be able to offer an extensive scope of supply from stock for all of our Actuated Valves. Incorporating Safe Area IP65, Intrinsically Safe & Explosion Proof designs from the 551 series of Asco Solenoid Valves we can cover all bases of specification. All of our Namur Asco Solenoid Valves are available for 3/2 Spring Return & 5/2 Double Acting Actuators and come complete with Manual Override, avoiding any complications that may arise from any on site power failures. Pressure ranges are suitable for 2-10 Bar Filtered, Lubricated/Non-Lubricated and Dry Compressed Air for the SCG551A001MS, LISC551B201 & NFETG551B301SL. Anodized Aluminium Bodies complete the design features with NBR & Polyurethane Seals accommodating temperature ranges of -25 to 60 DegC.