Everyday terms associated with solenoid valves from GC Valves and Components For Automation

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AC (or VAC)
- Alternating Current

AC Buzz or Hum - vibration associated with AC valves, the shading ring in intended to minimize hum, but ac rectification or dc voltage may be required to fully eliminate it

Back Pressure – condition where pressure on the outlet port exceeds the pressure on the inlet port; a check valve may be required because solenoid valves are not designed to hold back pressure

Body Material – standard GC Valves bodies are manufactured in Brass, Aluminum, Stainless Steel, Nylon and Noryl; CFA bodies include these materials and others used for scientific applications

BPT threads– British Pipe threads used in body ports available in both GC Valves and CFA products

Buna – see Nitrile (Buna is a proprietary blend)

Burst Pressure - The maximum pressure
which may be applied to a valve without causing external leakage

Coil – component incorporating copper wire winding which when energized provides the magnetic field which moves the valve plunger; standard CFA and GC Valves coils are fully encapsulated and operators incorporating them meet NEMA 4 or NEMA 4X specifications; the insulation material of the magnetic wire determines the rating:
- Most applications - Class F Coil – 155 degrees C
-  Hot Water, Steam and other high temperature applications - Class H Coil - 180 degrees C

Continuous Duty Coil -- a coil that can be energized continuously without overheating; standard CFA and GC Valves coils are rated for continuous duty

Holding Current -- expressed in amperes; indicates the amount of current flowing through the solenoid valves coil when
energized – source for product data, contact information and much more

Cycle Life --typical life expectancy expressed in cycles

Cv ( Flow Coefficient) -- The volume of water in US gallons per minute that flow through the valve with a pressure drop of 1 PSI

DC (or VDC) -- Direct Current

De-energized  -- the state of a valve where electrical current is not being applied to the coil

DIN Connector – international style tab coil with standardized connector system

Direct Acting – solenoid valve design utilizing the plunger to open and close the main orifice; direct acting valves do not require an operating pressure differential to operate

Diverting Operation – a single inlet and multiple outlets (used to refer to in-line 3-way valves and solenoid
valve manifolds

Duty Cycle – the percentage of the time that a solenoid valve is energized; most GC Valves and CFA solenoid valves are rated for 100% duty cycle (continuous duty)

Energized - valve is energized when current is supplied to the coil

Energy Efficient - Typical solenoid valves use 8 or 10 watt coils; new designs allow us to cut those values by 50% in many CFA designs

EPR, EPDM or Ethylene Propylene – an elastomer used with water, hot water, low pressure steam and other line fluids

Explosion Proof Housings –NEMA 7 available for most GC Valves products

Flow Coefficient (Cv) -- he volume of water in US gallons per minute that flow through the valve with a pressure drop of 1 PSI

Flow Direction -- the direction media must travel through the valve; the flow direction can be indicated by an arrow pointing from the inlet port to the outlet port or the words IN or OUT

Flow Rate -- volume flowing through valve: gallons-per-hour, gallons-per-minute, liters-per-hour etc.

Fluid or Media  – gas or liquid intended to be controlled by
the valve – source for product data, contact information and much more

GPM – gallons per minute

Heat Rise -- the increase in the coils internal temperature caused by self-heating

Inlet Port –  the “upstream” entrance to the valve from the source of the line fluid

Intermittent Duty Coil  – one that has a specified duty cycle; not used by GC Valves or CFA, Inc. for standard products

Latching Valve (or Magnetic Latching) – a permanent magnetic holds the valve in either open or closed position; valve is energized with a pulse to open and close; applied in battery powered applications and those where heat rise (heating the line fluid) is not acceptable

Leakage, External  -- unintended line fluid flow from inside the
valve to the outside

Leakage, Internal – unintended flow through the valve when closed

Line Fluid – gas or liquid intended to be controlled by the

Main Orifice -- opening through which media passes when flowing through a valve

Manifold (or Solenoid Valve Manifold) – assembly with
multiple inlets or outlets controlled by solenoid valve operators

Manual Override -  mechanical device that allows a manual opening/closing of the valve

Media - the liquid or gas that passes through the
valve; different media types include air and other gases, water, hot water, steam, chemicals, vacuum and combustible fluids

Media Isolated - a valve where a diaphragm or similar seal prevents the media from contacting the metallic elements of the operator; provided by CFA for scientific and high purity applications

Metering  or Metering  Pin - allows manual adjustment of fluid flow; typically found on an outlet port of a CFA or GC Valves solenoid valve or manifold

MOPD - Minimum Operating Pressure Differential -  pressure required between the inlet and outlet ports to open a pilot operated solenoid valve

Molded Coil (or encapsulated) -- the coil is encapsulated in epoxy or other suitable resin

NC - NormallyClosed – 2W NC – 2-way valves that are closed when de-energized (energize to open)

NEMA Housings – NEMA 4 or NEMA 4X for most GC Valves and CFA, Inc. solenoid valves; explosion proof NEMA 7 also available for most GC Valves products

Nitrile – the most common elastomer used in solenoid valves for air, water, oil and natural gas, and many other line fluids

NO – Normally Open – 2W NO – 2-way valves that are open when de-energized (energize to close)

No Lead - required in the US for drinking water by federal law starting in 2014; both GC Valves and CFA offer valves made from stainless steel and man made materials

Normally  Closed (NC) – closed when de-energized (energize to open)

Normally Open  (NO) -- open when de-energized (energize to close)

NPT threads -- National Pipe Thread is standard for ports in GC Valves and CFA products (other threads available)

​NSF 61 - If you manufacture, sell or distribute water treatment or distribution products in North America, your products are required to comply with NSF/ANSI Standard 61: Drinking Water System Components – Health Effects by most governmental agencies that regulate drinking water supplies.

Operator - electro-mechanical  component of solenoid valve including moving parts

Orifice - An opening through which media passes when
flowing through a valve. The orifice is opened and closed to control the flow of media through the valve

Outlet Port – a downstream exit from the valve which connects line fluid to the application

Oxygen Cleaned – hydrocarbons removed by special cleaning regimen

Pilot Operated Valve (also Servo Operated) - uses line pressure to open or close a diaphragm or piston. MIN OPD describes the minimum pressure differential at which these valves will fully open

Pilot Orifice
– The precise internal opening within the valve body which is controlled by the operator in pilot operated valves

Pinch Valve - A solenoid operated device
used to pinch flexible tubing for the purpose of controlling flow

Plating – most commonly the use of thin coatings of inert materials to protect magnetic grades of stainless steel inside the operator from external attack; can also be used on bodies and to protect solenoid valve components from external attack

Plunger -The moving component of a solenoid valve which
opens and closes an orifice.  GC Valves and CFA plungers incorporate soft seals that contact the orifice to shut off flow

Port – an external connection of the valve to the line media; may be Inlet or Outlet

Power Consumption - electrical energy (watts) supplied to the coil to maintain its operation.

Pressure Drop – reduction of pressure from inlet to out of valve; used in flow calculations

PSI - pounds per square inch; a measurement of pressure

PSIG -- PSI (gauge); Pressure referenced to ambient air pressu

Rectifier - An electrical device for converting alternating current to direct current

Response Time - The time it takes the valve's operating mechanism to move from closed to open or open to closed position

Rulon – a family of PTFE that exhibits an increased wear resistance over standard PTFE

SAE threads – commonly used in refrigeration, automotive and low pressure applications

SCFM -- The cubic feet of per minute of gas measured
at standard conditions (70° F and 14.7 PSIG - Sea Level)

SCFH  -- The cubic feet of per hour of gas measured at standard conditions (70° F and 14.7 PSIG - Sea Level)

Santoprene – a seal material preferred for diaphragms for NSF-61applications

Seal – the valve component that  stops the flow by sealing against a metallic seat or orifice

Seat –the metallic valve component that the elastomeric seal contacts to stop flow

Servo Operated Valve (also Pilot Operated) -- uses line pressure to open or close a diaphragm or piston; this design may require a minimum operating pressure differential to provide full flow

Shading Ring – the dissimilar metallic component pressed in the tube head of an AC valve to minimize the oscillation or hum associated with AC valves; typically copper, silver or aluminum

Soft  Seal - The elastomer or other non-metallic material at the end of the plunger that contacts an orifice

– preferred seal for steam and hot water applications

VAC - Alternating Current

Vacuum - a pressure less than atmospheric pressure

- Direct Current

- resistance to flow or "stickiness" of a fluid; high viscosity fluids may not be suitable for effective solenoid
valve operation

Viton – an FKM that is used for many general purpose
sealing applications; the standard seal in CFA direct acting valves and many GC Valves products

XTREME Valves – GC Valves product line used in air suspensions

Zero Operating Pressure Differential Design – normally refers
to diaphragm solenoid valves that require no pressure differential to fully open

Chuck Stevens

Northeast Region Manager - GC Valves, LLC.

724-772-8900                   fax 412-202-9616