AIGI Environmental Inc.
AIGI 29 High-Temperature/High-Pressure Valve Packing
AIGI 29 is a heavy-duty valve packing of nickel-wire-reinforced flexible-graphite yarn, jacketed in knitted nickel wire and coated with special blocking agents for enhanced sealability. The combination of graphite's extreme temperature resistance and the nickel wire's outstanding extrusion resistance makes it the natural choice for high-temperature, high-pressure steam valves. Its chemical resistance extends its reach into refinery and petrochemical valve service as well.
Product Benefits
- Two failure modes solved: At severe steam conditions, ordinary packing fails in two ways: the material degrades in the heat, or it extrudes through the gland clearances under pressure. AIGI 29 answers both.
- Extreme heat capability: Flexible graphite shrugs off extremely high temperatures.
- Locked against extrusion: The nickel-wire reinforcement and knit jacket lock the rings in place against extrusion even at very high pressures.
- Tight shut-off: The special blocking-agent coating seals the fine leak paths through the braid, giving tight shut-off on valves where fugitive steam or chemical leakage is costly or hazardous. The result is a packing that can be trusted on the most demanding valves in the plant.
Where It's Used
- High-pressure steam valves: Its home ground is high-temperature, high-pressure steam valves; main steam, boiler and turbine-loop valves in power plants are classic examples.
- Refinery and petrochemical valves: It also seals valves handling aggressive media in refineries and chemical and petrochemical plants.
- Broad chemical resistance: Graphite's chemical resistance spans the full acid-to-alkali range.
Good to Know
- Valves only: This is a dedicated valve packing, engineered for static and slow-moving stems rather than rotating shafts; for pump-and-valve general service the wire-free AIGI 28 from the same graphite family is the usual companion.
- Careful installation pays: The nickel-wire construction makes the rings firm, so correct ring sizing and careful seating pay off at installation.
- Black graphite colour: The packing is black and, like all graphite products, is best kept away from services where colour purity of the media matters.
- Combination ring sets: In critical valves it is common practice to combine such wire-jacketed rings with softer graphite rings to balance extrusion resistance and sealability.
