Free engineering calculators and unit convertersceo@instrumentationblog.in
Control Valve · Glossary

What is Valve Packing?

stem sealControl Valve

Valve packing is the seal around the valve stem that stops process fluid leaking out while allowing the stem to move.

Advertisement

Valve Packing Explained

PTFE packing has low friction for clean, moderate temperatures. Graphite handles high temperatures but has more friction. Live loaded packing uses springs to keep the seal tight as it wears.

Packing friction is a main cause of stiction, so tightening packing to stop a leak can spoil control.

Advertisement

Calculators for Valve Packing

CalculatorActuator Thrust CalculatorFree online calculator with formula and worked example.

Free Downloads

Free downloadControl Valve Datasheet Template in Excel with Cv CheckFree download in Excel and PDF.Free downloadControl Valve Stroke Test ProcedureFree step by step procedure, Word and PDF.

Frequently Asked Questions

What is Valve Packing?

Valve packing is the seal around the valve stem that stops process fluid leaking out while allowing the stem to move.

What is low emission packing?

Packing designed and tested to limit fugitive emissions, for example to ISO 15848 classes.

Why check stroke after repacking?

New packing changes friction, which affects calibration and response.

You May Also Like

Learn more on the blog

Control valve passing causes

A practical guide on instrumentationblog.in with more detail on valve packing and how it is applied on real plants.

Read Full Article

Related Terms

Valve termValve StictionValve stiction is static friction that makes a valve stick, then jump, instead of moving smoothly,…Valve termValve ActuatorA valve actuator is the device that produces the force or torque to move a valve, using air pressure,…Valve termValve TrimValve trim is the set of internal parts in contact with the flow that control it, such as the plug, seat,…

More Control Valve Terms

Valve termVolume BoosterA volume booster is a pneumatic relay that copies the positioner output at much higher air flow, to…Valve termControl ValveA control valve is a power operated valve that varies flow in response to a signal from a controller, to…Valve termFlow Coefficient (Cv)Flow coefficient Cv is the flow of water in US gallons per minute through a valve with a pressure drop of…Valve termKv Flow FactorKv flow factor is the flow of water in m³/h through a valve with a pressure drop of 1 bar; it is the…Valve termValve CharacteristicValve characteristic is the relationship between valve travel and flow coefficient, such as linear, equal…Valve termInstalled CharacteristicInstalled characteristic is the actual relationship between valve travel and flow once the valve is in…

All control valve terms · Full glossary A to Z

Advertisement