Glossary of Terms
|
| Click on a term to view its definition |
 |
|
|
Bubble-tight Sealing - |
Air leakage between the internal sealed ports of a valve in either the energized or de-energized position is undetectable in a 5 second soap bubble test.
 back to top |
Current Drain - |
The amount of current (expressed in amperes) that flows through the coil of a solenoid valve when it is energized.
back to top
|
Continuous Duty - |
A rating given to a valve that can be energized continuously without overheating.
back to top
|
Cv Factor - |
The Cv factor of a valve is the quantity of 60F water, expressed in gallons per minute, which will flow through a valve with a one PSI pressure drop. Spartan Cv factors for solenoid valves are listed for each series in the catalog.
back to top
|
Cycle - |
The normal opening of a closed valve and then closing is one complete cycle.
back to top
|
Cycle Rate - |
The number of times a valve can open and close in a given time frame.
back to top
|
Dead-End Gas Service - |
A condition in which a valve is energized but has no cooling fluid flowing through it because of a dead-end line (a cylinder pressurized for a long period).
back to top
|
Drip-Proof - |
See NEMA classifications.
back to top
|
Dust-Tight - |
See NEMA classifications.
back to top
|
Duty Cycle - |
The longest time that a valve is energized, followed by the shortest time that it is de-energized. Expressed in percent = ON / (ON + OFF)
back to top
|
Explosion-Proof Construction - |
A solenoid valve constructed to meet the specifications of Underwriter's Laboratories, Inc. for operation in hazardous locations. See NEMA classifications also.
back to top
|
Flow - |
The movement of fluid created by a pressure differential.
back to top
|
Flow Capacity - |
The amount of fluid a valve will pass under given temperature and pressure conditions in gallons per minute or cubic feet per minute as measured at the outlet port. Cv is a measure of flow capacity.
back to top
|
Flow-Rate - |
The amount of fluid that passes a given point at a given period of time.
back to top
|
Floating Bottom or Top Seal - |
A plunger assembly construction in 2-way and 3-way valves in which the seal is movable against a spring within the plunger.
back to top
|
Flux Plate - |
A magnetic steel plate used in the magnetic circuit of a solenoid valve to help carry magnetic flux from the enclosure to the sleeve assembly. A flux plate is required on valves with non-metallic body material.
back to top
|
General Purpose Valve - |
Valves suitable for application indoors under normal atmospheric conditions. See NEMA classifications.
back to top
|
Intermittent Duty Coil - |
A valve coil not designed for continuous duty but which will perform satisfactory for a specified duty cycle.
back to top
|
ISO 9000 - |
International standard of quality.
back to top
|
Heat Rise - |
The difference between the stabilized temperature of the solenoid coil when energized and de-energized in a constant ambient temperature. As current flows through a coil, heat is generated. The coil temperature rises until the coil enclosure dissipates heat as fast as it is generated, and the temperature stays at a stabilized level.
back to top
|
Insert - |
A material used in the plunger assembly to seal an orifice.
back to top
|
| Insert Materials - |
|
Buna-N - |
A soft synthetic rubber which has excellent compatibility characteristics for most air, water and light oil applications up to the 180F - 200F range.
|
|
Ethylene -
Propylene
(EPDM) |
A soft synthetic rubber which is suitable for water above 180F and steam under 50 PSI. EPDM has a wide range of fluid compatibility but cannot be used with petroleum based fluids or fluids so contaminated (such as lubricated air).
|
|
Kel-FR** - |
A combination of carbon and halogens which yields a colorless material that is exceptionally stable, temperature resistant, chemically inert, and a true thermo plastic. The Kel-FR** plastic is an extremely versatile material and is impervious to the action of corrosive chemicals and highly resistant to most organic solvents.
|
|
Nitrile - |
See Buna-N.
|
|
Teflon* - |
A synthetic material used for many semi-corrosive and corrosive media. It is virtually indestructible by any fluid, and its temperature resistance makes it especially suitable for steam application. TeflonR* has excellent lubricating characteristics. It is not recommended for vacuum service.
|
|
Viton* - |
A soft fluorocarbon insert material, developed primarily for handling hydrocarbons and high temperatures. VitonR* is the standard seal materials in most Spartan Scientific general purpose direct poppet 2-way and directional 3-way valves. |
back to top |
Leakage, External - |
The leakage between the internal part of the valve and the external part of the valve. Spartan valves are bubbletight.
back to top
|
Leakage, Internal - |
The leakage between the internal sealed ports of a valve in either the energized or de-energized position. Leakage rate is normally closed described in cc (cubic centimeters) per minute or as bubbletight.
back to top
|
Manual Override - |
A mechanical device that permits manual opening of normally closed valves or closing of normally open valves.
back to top
|
Metering - |
A mechanical device that permits manual adjustment of fluid flow through a valve. Speed control.
back to top
|
NEMA CLASSIFICATIONS -
(Solenoid Enclosures) |
|
Type 1: |
General Purpose - Enclosures are intended for indoor use, primarily to prevent accidental contact of personnel with the enclosed equipment in areas where unusual service conditions do not exist.
|
|
Type 2: |
Drip-Proof - Enclosures are intended for indoor use to protect the enclosed equipment against falling non-corrosive liquids and falling dirt.
|
|
Type 3R: |
Rainproof and Sleet Resistant (Ice Resistant) - Enclosures are intended for outdoor use to protect the enclosed equipment against rain, sleet and external ice formation.
|
|
Type 4: |
Watertight and Dust-Tight - Enclosures are intended for indoor or outdoor use to protect the enclosed equipment against splashing water, seepage of water, falling or hose-directed water and severe external condensation.
|
|
Type 4X: |
Watertight, Dust-Tight and Corrosion-Resistant - Enclosures have the same provisions as Type 4 enclosures and are corrosion-resistant.
|
|
Type 6: |
Submersible - Enclosure protected against entry of water during occasional temporary submersion at a limited depth.
|
|
Type 7: |
Explosion-Proof - Designed to be used in a hazardous atmospheres classified as Class I, Groups A, B, C or D, as defined by NEC (National Electric Code). The explosion-proof enclosure must be able to withstand an internal explosion and prevent the ignition of atmospheric gases which may be caused by the shorts or sparks occurring within the enclosures. Additionally, the external enclosure temperature must be low enough as to not ignite a surrounding flammable atmosphere.
|
|
Type 9: |
Class II, Division I, Group E, F or G - Enclosures are intended for indoor use in the atmospheres and locations as defined as Class II, Division I or Division II, and Group E, F or G in the NEC to prevent the entrance of explosive amounts of hazardous dust. If gaskets are used, they must be of non-combustible, non-deteriorating, vermin proof material.
|
|
Type 12: |
Industrial Use - Dust-Tight and Drip-Tight - Enclosures are intended for indoor use to protect enclosed equipment against fibers, filings, lint, dust and dirt; and light splashing, seepage, dripping and external condensation of non-corrosive liquids. |
back to top |
Port - |
An opening or passageway for the inlet or outlet of a fluid in a valve. The terminus of the port is threaded (NPT) to accommodate a line connection. A port designated with an NPTF indicates dry seal threads.
back to top
|
Port, Cylinder - |
A port which provides a passage to or from an actuator.
back to top
|
Port, Exhaust - |
A port which provides a passage to the atmosphere.
back to top
|
Port, In - |
A port which provides a passage from the source of fluid.
back to top
|
Port, Out - |
A port where the fluid leaves a two-way valve.
back to top
|
Port, Normally Closed - |
A port that is closed to fluid flow when the valve is de-energized.
back to top |
Port, Normally Open - |
A port that is open to fluid flow when the valve is energized.
back to top
|
Power Consumption - |
The number of watts a solenoid valve draws when energized.
back to top
|
Pressure - |
Force per unit area. Pressure is induced into a system by means of a pump, compressor or by gravity. Pressure may be expressed as pounds per square inch absolute (PSIA) or as pounds per square inch gauge (PSIG). PSIG is most often used for valve ratings and is 14.7 PSI greater than absolute pressure, when measured at sea level.
back to top
|
Burst Pressure - |
The maximum pressure that would not cause the weakest section of the valve to fail and cause external leakage when pressure is reduced back to rated pressure. Depends on the individual valve construction. For most valves it is at least 5 times rated pressure.
back to top
|
Pressure, Differential (Drop) - |
The difference in pressure measured between two given points. (P1 - P2).
back to top
|
Maximum Operating Pressure -
Differential (MOPD) |
The maximum difference in pounds per square inch between the pressure at an inlet port and the pressure at an outlet port at which a solenoid valve will operate.
back to top
|
Minimum Operating -
Pressure Differential |
The minimum difference in pounds per square inch between the pressure at an inlet port and the pressure at an outlet port required for proper operation of the solenoid valve. The minimum operating pressure must be maintained throughout the operating cycle of pilot-operated valves to ensure proper shifting from the closed position to the open position or vise versa. Note: 2-way and 3-way pilot-operated valves will start to move to their normal positions when the pressure falls below the minimum operating pressure. Direct acting valves do not require a minimum pressure to operate.
back to top
|
Proof Pressure - |
The maximum pressure the valve may be exposed to without suffering any damage. It does not have to be capable of operating at this pressure. For most valves it is at least 1-1/2 times the rated pressure. (This is a non-destructive test).
back to top
|
Response Time - |
The length of time required for an operating mechanism of a valve to move from the fully closed to the open position, or vice versa. Response time will vary according to pressure, fluid, voltage and system. It also varies with type of valve (direct operated or pilot operated). For specific valves, consult factory with complete application details.
back to top
|
Spring-Loaded - |
The term used to indicate that the valve has a plunger return spring. A spring-loaded plunger permits the valve to be mounted in any position without causing malfunction.
back to top
|
Temperature Range - |
Spartan Scientific valves are equipped with high quality coils suitable for continuous energization. The permissible coil temperature, as measured by the change in resistance method, is 155C for Class F and 180C for Class H.
back to top
|
Vibration and Shock - |
Most valves will resist 10 G's or more
back to top
|
