CONSTRUCTION
Valve body
Main part of the valve with all ports and main seats.
Core
Plugnut of soft-magnetic stainless steel moved by magnetic forces (flux generated by the coil).
Shading coil
Ring (typically copper), inserted in the core side surface of the plugnut, to limit vibration of the core in case of AC powered coils.
Core tube
Stainless steel tube, closed at one end of the core tube, installed to improve the magnetic flux of the solenoid coil upon energisation.
Coil
Electrical part of the valve consisting of a spool wound with insulated copper wire creating a magnetic flux when energised.
Plugnut
Stationary core, pressed in the closed end of the core tube, installed to improve the magnetic flux of the solenoid coil upon energisation.
Solenoid
Assembly of the electro-magnet, non comprising moveable parts.
Solenoid enclosure
Metal housing around the coil for electrical and mechanical protection, as well as protection against ingress of water or dust.
Core
Plugnut of soft-magnetic stainless steel moved by magnetic forces (flux generated by the coil).
Shading coil
Ring (typically copper), inserted in the core side surface of the plugnut, to limit vibration of the core in case of AC powered coils.
Core tube
Stainless steel tube, closed at one end of the core tube, installed to improve the magnetic flux of the solenoid coil upon energisation.
Core-spring
Spring, which keeps the core in fixed position, when the coil is de-energised.
Bonnet
Screwed plug or bolted cover on the valve body on which the core tube with inner parts is fitted.
Disc, valve disc
Sealing material on the core or disc-holder which shuts off the seat orifice.
Disc-holder
Valve part, actuated by the core, in which the sealing disc is inserted.
Disc spring
Spring in the disc-holder which provides a positive closing action to the disc.
Seating or valve seat
Specially formed border of the main valve.
Main orifice
Principle passage between inlet and outlet of the valve.
Bleed-orifice or bleedhole
Permanently open, small orifice or channel, mostly located in the diaphragm or piston of pilot operated valves to allow the inlet flow to pressurise the top side of the diaphragm or piston.
Pilot orifice
Orifice located in the centre of a diaphragm or a piston of pilot operated valves, opened or closed by the core.
Solbase assembly
Assembly of core tube, plugnut and bonnet.
Maximum Operating Pressure Differential (PS)
The maximum operating pressure differential is the maximum differential pressure between the inlet and the outlet sides of the valve against which the solenoid can safely operate. If the pressure at the valve outlet is nog known, the conservative approach is to regard the M.O.PD. as the supply pressure.
Minimum Operating Pressure Differential
The minimum operating pressure differential is that which is required to open the valve and keep it open. For 2 way valves with floating piston or diaphragm, the valve will start to close below the minimum differential pressure.
For 3 and 4 way pilot valves the minimum operating pressure is measured between the pressure and exhaust ports and must be maintained throughout the operating cycle to insure complete transfer from one position to the other.
Note: Direct acting hung diaphragm or hung piston valves do not require a minimum operating pressure
Maximum Allowable Pressure
Line or system working pressure to which the valve may be safely subjected without causing damage to the valve if not exceeding the MOPD (according to EN-764).
Minimum Ambient Temperature
The nominal limitation of O°C is advisable for any valve that might contain moisture (wafer vapour). Where freezing water is not a factor, minimum ambients as low as -20°C/-25°C can be tolerated. In addition, special constructions are available for ambient temperatures down to -40°C.
Maximum Ambient Temperature (TS)
The nominal maximum ambient temperatures listed are based primarily on test conditions in determining safe limits for coil insulation. They are energised conditions and with maximum fluid temperatures existing in the valve.
Response time
This is the timelapse after energising (or de-energising) a solenoid valve until the outlet pressure reaches a specific percentage of its maximum steady value, the outlet being connected to a circuit having specified flow parameters. Response time depends on 5 factors:
1. Electrical supply: AC or DC.
2. Fluid handled by the valve, viscosity and pressure level
3. Type of operation: direct or pilot operated
4. Size of the moving parts of the valve mechanism
5. Circuit in which the time is measured.
Types of valves
2/2 (2-Way Valves)
Two way valves have one inlet and one outlet pipe connection. Valves are availablein either:
Normally Closed Construction
Normally Open Construction
Valve is closed when energised and open when de-energised.
Direct Acting Solenoid Valves
2 way solenoid valves has an inlet and an outlet connection in the valve body.
The operation, in both cases, depend only on the magnetic field produced by the coil.
This type of solenoid valve is able to work at zero pressure.
Assisted Lift Solenoid Valves
With these models the armature is mechanically attached to the diaphragms controlling the central pilot orifice and the stroke of the main seal.
This design allows the valves to work at zero differential pressure.
Pilot Operated Solenoid valves
Relies on a differential of pressure between input and output, the pressure at the input must always be greater than the pressure at the output for the valve to operate. Should the pressure at the output, for any reason, rise above that of the input then the valve would open regardless of the state of the solenoid and pilot valve.
3/2 (3-Way Valves)
Three way solenoid valves have three pipe connections and two orifices. When one orifice is open the other orifice is closed. These valves are commonly used to alternately apply pressure to and exhaust pressure from a diaphragm valve or single acting cylinder.
Three modes of operations are available:
Normally Open Construction
With the valve de-energised, the pressure port is connected to the cylinder port and the exhaust port is closed. With the valve energised, the pressure port is closed and the cylinder port is connected to the exhaust port.
Universal Construction
Allows the valve to be connected in either the normally closed or normally open mode. In addition, the valve may be connected to select one or two ports (selection) or to divert flow from one port to another (diversion).
4/2 and 5/2 (4-Way Valves)
Four way solenoid valves are generally used to operate double acting cylinders. These valves have four or five pipe connections - one pressure, two cylinder and one or two exhausts. In one valve position pressure is connected to one cylinder port; the other is connected to the exhaust. In the other valve position, pressure and exhaust are reversed at the cylinder connections.
Two types available:
1. Single Solenoid - This type of operation is used where automatic return of valve on electrical power failure is required.
2. Dual Solenoids - Dual solenoid valves are used where equipment must not change position when electrical power fails. Complete safety is guaranteed for personnel and equipment at all times.
Solenoids may be energized momentarily or continuously, depending upon the application.
Manual Reset Valves
The manual reset valve must be manually positioned (latched). It will return to its original position when the solenoid is energised or de-energised, depending upon the construction.
Four modes of operation are possible:
Electrically Tripped
Latched Open: Valve is opened manually and held open by the latch until tripped closed when the solenoid is momentarily or continuously energized.
Electrically Tripped
Latched Closed: The valve is latched closed by shifting the sleeve downward when the solenoid is de-energized. Upon energization, the core and attached trip stem are pulled upward to trip the lock. The return spring then opens the valve.
No Voltage Release
Normally closed: Valve is opened manually and held open by a continuously energized solenoid. Valve trips closed when the solenoid is de-energized and remains closed until manually opened.
No Voltage Release
Normally Open: The valve is latched closed by shifting the sleeve downward when the solenoid is energized. Upon deenergization, the core and spring trip the lock and open the valve.
NOTE: Most listed manual reset valves have a 3/2 way Universal (U) function allowing a choice for Normally Closed (NC), Normally Open (NO) or selection or diversion of flow.
Other possible models of operation are:
Flow through the valve at the users place by manually operating the valve (de-energized). Return to the rest position (energized); all the manual actions resulting in flow changes are only permitted in case the supply voltage is present. The two applicable function models are Normally Closed (NC) and Normally Open (NO).
