NACE - National Association of Corrosion Engineers. : NACE are an association of technical engineers that write and publish papers relating to all aspects of corrosion and have written specific valve standards for valve corrosion in particular for valves for sour gas service.
NBR seals : NBR is an elastomer seal material (Nitrile Buna Rubber) or referred to as Butadiene Acrylonitrile which is found in most valves as a standard or general purpose sealing material. NBR will work up to +80°C possibly +100°C for a short time. NBR withstands ageing well with good abrasion resistance but poor resistance to sunlight (UV rays). NBR has good resistance to Aliphatic Hydrocarbons, Petroleum, Fuels, Mineral Oil, Vegetable and Hydraulic Oil, Alcohol and many Acids. NBR has poor resistance to Ozone, Acetone, Methyl ethyl Ketone, Chlorinated Hydrocarbons, Ethers and Esters.
Needle Valve : A needle valve is typically a small compact valve with an internal needle or tapered point that can move into or away from a small sealing orifice offering variable flow control for metering applications.
NEMA - National electrical Manufacturers Association : NEMA classification which is a set of guidelines for electrical equipment, such as degrees of ingress and ATEX protection as used for solenoid valves. Can be converted to IP65 see IP protection.
Non Destructive Testing : A valve pressure, function or flow test that does not damage or destroy the valve being tested.
Normally Closed Solenoid Valve : Normally closed refers to the normal state of the solenoid valve in the fail safe (electrical power off) position of the valve as Closed. So without power the valve is "normally closed" preventing the flow of media through the valve.
Normally Open Solenoid Valve : Normally open refers to the normal state of the solenoid valve in the fail-safe (electrical power off) position of the valve as Open. So without power the valve is "normally open " allowing the flow of media through the valve.
Norsok Standard : NORSOK standards are used by the Norwegian Petroleum Industry to unsure a cost effective yet prudent safety levels for all offshore and onshore petroleum industries and processes.
NPS - Nominal Pipe Size : Indicates the port size of a valve which can be used for matching valves sizes connection onto other pipelines or valves.
NPT - National Pipe Tapered Thread : NPT thread is an American standard tapered thread standard.
NRS - Non Rising Stem : A typically multi turn valve those stem is threaded into the valve gate, the stem will turn but not rise from the valve body. Non rising stem threads are exposed to the media inside the valve body.
OCMA - Oil Companies Materials Association : Association of British Oil Companies that have written standards for fire safe testing of valves.
OD - Outside Diameter : OD or outside diameter is the measured external diameter of a circular pipe or tube.
Opening Time : The opening time of a valve is the time required typically from 20 milliseconds to 5 seconds for a valve to move from the fully closed position to the fully open position. Note that solenoid valves open much faster than actuated valves.
Operation : Solenoid valve operation is the way the solenoid valve is designed to operate. This can be direct acting, assisted lift or servo assisted.
Operating Time : The measured time required for a valve to move from the fully closed position into the fully open position, or the time for an actuated valve to move from one extreme position into the fully opposite position.
Operator : A mechanical device that converts electrical energy into mechanical motion, sometimes referred to as a solenoid armature. An operator can also be a device that converts pneumatic, hydraulic or electrical energy into mechanical force or motion.
Orifice size : The orifice of a solenoid valve is given as the internal diameter in mm or inches of the valve sealing face where the media passes through and is controlled by a piston or diaphragm sealing against it. A valve with a 25mm orifice will typically offer high flow of media than a valve with a smaller orifice of say 20mm.>
O Ring : An O ring is a circular round sealing ring typically an NBR, FKM or EPDM elastomer seal that has a circular cross section.
Oxygen cleaned : See degreased