A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Safety Factor Is a factor applied to the nominal operating torque or thrust given by the valve manufacturer. Can be between 1.2 and 2.0 depending on application. Safety Relief Valve A quick-acting spring-loaded valve that opens (relieves) when the pressure exceeds the spring setting. It specifically opens proportionally with pressure increasing. Often installed on … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Ra (Roughness: Arithmetic Average Deviation) It is the arithmetic average of the absolute values of the profile deviations from the mean line of the roughness profile. Statistically very stable repeatable parameter good for random type surface such as grinding. Not a good measure of sealed surfaces. Reduced Port (Bore) See Venturi Valve. Regulator A … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y QEV (Quick Exhaust Valve) A one-way valve connected directly to the actuator cylinder. Having a large exhaust port, it allows fast dumping of air from the cylinder directly to atmosphere. Qualification Test Additional testing requirements are performed on a product to determine whether or not the product conforms to all of the requirements of … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y Potentiometer The principle of its operation is that a voltage gradient is generated across a resistive element which has a variable pick off point connected to the valve stem. As the stem moves, the voltage changes across the potentiometer to provide an electrical output of the valve position. Power Operator Powered valve operators are … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y OD (Outside Diameter) The measurement of the outermost diameter of a circular part. Operator A device which converts manual, hydraulic, pneumatic or electrical energy into mechanical motion to open and close a valve. Also called a Valve Actuator. O-Ring An elastomeric or synthetic seal ring of circular cross section. Operating Temperature A media temperature … Read more
A–B–C–D–E–F–G–H–I–J–K–L–M–N–O–P–Q–R–S–T–U–V–W–X–Y NACE International A professional organization for the corrosion control industry established in 1943 which publishes papers articles and standards on all aspects of corrosion and has written the definitive standard for valve materials for sour gas service. Formerly known as the National Association of Corrosion Engineers. www.nace.org National Pipe Thread A US standard for … Read more