MAXIFLEX SPIRAL WOUND
GASKETS
Maxiflex spiral wound gaskets have the ability to recover under the
action of fluctuating loads caused by process fluid pressure and
temperature changes, flange face temperature variations, flange
rotation, bolt stress relaxation and creep. The gasket sealing
element consists of a pre-formed metallic winding strip with layers
of a softer, more compressible sealing material which, during
compression, is densified and flows to fill imperfections in the
flange surfaces. The metal strip holds the filler giving the gasket
mechanical resistance and resilience.
Product Advantages
Maxiflex spiral wound gaskets combine the ease of sealing a graphite,
PTFE or mica filler with the strength afforded by a specially
profiled metallic, spring-like reinforcement. The sealing element is
manufactured by interleaving plies of alternating metallic winding
strip and filler to create a gasket that is robust and easy to
install. Maxiflex spiral wound gaskets create a very tight and
reliable seal suitable for high temperature and pressures and can be
manufactured to suit standard flanges and also custom-designed
vessels.
Maxiflex gaskets are capable of giving an excellent seal over a wide
range of flange surface finishes, but as a general guide we suggest
under general duties, a flange surface finish of 125-248
µin (3.2 - 6.4 µm)
Maxiflex Spiral Wound Gasket Construction
Several layers of specially formed continuous chevron-shaped metal
strips are spirally wound with alternate plies of soft filler strip
to make the gasket’s basic sealing element. The chevron profile
allows the gasket to act as a spring and the depth is carefully
controlled to give the sealing element the best compression and
recovery characteristics. Maxiflex spiral wound gaskets are
manufactured to specifications of ASME B16.20.
Computer controlled winding machines carefully monitor and adjust the
tension of the winding strips. A uniform density throughout the
product is produced. This provides the spring like action within the
gasket that resists buckling and maintains a seal even when subject
to fluctuating compressive loads.
Maxiflex Thickness After Installation
Spiral wound gaskets are manufactured in a number of standard thicknesses
which are designed to compress to a specific thickness to attain the
best sealing performance and adaptation to the flanges. The thickness is
measured to the metallic windings not to the filler.
Applications
- Spirals wound gaskets are widely used in piping and
pressure vessel flange connections, in medium to high
pressure and temperature duties.
- The sealing element of a spiral wound gasket is
manufactured from a preformed metallic strip in
combination with a soft filler material.
- Inner and / or outer rings can be incorporated to suit
the flange face design and application
parameters.
Dimensions
- The dimensional requirements for spiral wound
gaskets are provided in ASME B16.20
for various flange standards.
- Gaskets are also available to meet the dimensional
requirements of other flange standards, such as EN
or JIS.
- Custom sized gaskets can be produced from customer
supplied information.
- Three standard sealing element thickness options
are available, i.e., 0.125", 0.175" and 0.250".
Other thicknesses are available on request.
Materials
- Sealing element winding strip: Austenitic and
duplex stainless steel grades as well as other
exotic alloy steels.
- Sealing element filler material: Flexible
graphite, PTFE and mica.
- Custom sized gaskets can be produced from customer
supplied information.
- Three standard sealing element thickness options
are available, i.e., 0.125", 0.175" and 0.250".
Other thicknesses are available on request.
Style R -
Sealing element only
- Wide choice of materials for filler and
metallic strip
- Suitable for high pressure and high
temperature applications
- Recommended flanges: tongue and groove, male
to female and flat face to recess in
vessels, valves and pumps
- General and critical duties
Style CR -
Sealing element with outer ring
- Solid metal outer ring used as a centering
device and compression stop
- Used mainly on raised face and flat face
flanges
- Wide choice of material for filler and
metallic strip
- General duties
Style CRIR -
Sealing element with inner and outer
ring
- Solid metal inner and outer rings
- Suitable for high pressure and high
temperature applications
- Standard spiral wound gasket for raised face
or flat flanges
- Prevents turbulence and erosion damage to
flange
- Prevents damage to the gasket bore and inner
windings
- Inner ring acts as a heat shield and
corrosion barrier
- Wide choice of material for filler and
metallic strip
- General and critical duties
Style RIR -
Sealing element with inner ring
- Solid metal inner ring
- High pressure and high temperature
capability
- Male to female flanges in vessels, valves
and pumps
- Wide choice of materials for filler and
metallic strip
- General and critical duties
Style HTX -
Style RIR with inner ring and centralizing
overwind
- A combination of inner and outer rings
- The inner ring could have pass bars or carry
either a metal clad or soft gasket with pass
bars
- Manufactured to customer designs
- Wide choice of materials for filler and
metallic strip
- Manufactured with thin outer windings to
create stable, large diameter gaskets for
narrow heat exchanger applications
Maxiflex Pro -
Style CRIR with Maxiprofile inner
ring
- High integrity, dual seal gasket specially
designed for service in highly critical,
corrosive applications where sealing
performance is of paramount importance
- Recommended for use in highly aggressive
chemical applications