Metal winding gasket is a sealing washer is used widely at present, as the recovery best gaskets semi metallic gasket, by V or W shaped steel strips with various fillers and alternatewinding, high temperature, high pressure and adapt to the use of ultra low temperature and vacuum conditions, by changing the metal winding gasket material combination, can solve the problem of chemical corrosion of various media of gasket.
Metal winding gasket structure density can according to different requirements to lock force production, to strengthen the body and accurate positioning, spiral wound gasket is provided with a ring and outer ring reinforced metal,using internal and external steel ring to control its biggest compaction degree, do not ask high-precision sealing surfaceof flange on the gasket contact.
Metal winding gasket main purposes: excellent resiliencemetal winding gasket pressure thermal cycling and vibrationof the piping system is automatically adjusted, particularly applicable to load uneven, joint force is easy to relaxation,where the temperature and pressure change periodically,shock or vibration. The original is the static sealing flange connection valves, pumps, heat exchangers, towers, manhole, hand hole, widely used in petrochemical, machinery, electric power, metallurgy, shipbuilding, medicine, atomic energy and space sectors.
In the metal winding flange gasket design for easy installation, according to the size of the gasket, peripheral bonding 2~8 positioning belt, make positioning buckles in flange holes, to prevent the installation gasket shiftor fall off, save the auxiliary materials and working hours. Generally divided into the following types:
Metal Spiral Wound Gasket:
(1) basic metal winding gasket
(2) with outer ring metal winding gasket
(3) with inner metal winding gasket
(4) with inner and outer ring metal winding gasket
(5) for a heat exchanger (ribbed) metal winding gasket
(6) shaped metal winding gasket
Metal winding gasket (basic) using high-quality SUS304,SUS316 (“V” or “W” shape) metal belt and material and other alloys, graphite, asbestos, non asbestos PTFE soft material such as overlapping spiral wound together, at the beginningand end of the metal belt is fixed by spot welding.
1 Metal Spiral Wound Gasket Metallic Materials
A. with a thickness of 0.15mm~0.25mm and 08F, 0Cr13, 0Cr18Ni19Ti, 0Cr18Ni9Ti, 00Cr18Ni10, 0Cr18Ni12Mo2Ti, 00Cr17Ni14Mo2, 201, 304, 316, cold rolled strip, or determined by both sides.
B. metal belt type V or type W narrowband pre forming, the surface should be smooth, clean, should not be rough,cracks, scratches, pits and rusty stain.
C. stainless steel hardness value HV ≤ 200
D. general strip width is 3.2mm, 4.5mm, 8mm, W strip typecan be more thick.
2 Metal Spiral Wound Gasket Non Metallic Materials
A non-metallic filler for special asbestos tape, flexible graphite belt, Teflon tape, non asbestos fiber, ceramic fiber and mica tape. With the thickness of 0.3-1.0mm.
B. asbestos ignition loss must be ≤ 25%
C. non 100PPM chloride content ≤ metal belt
D. all kinds of medium and the kinds of non – metal bandrecommended the use of temperature and pressure
E. general strip width is 3.2mm, 4.5mm, 8mm
3 Metal Spiral Wound Gasket inner and outer ring Materials
Commonly used with 304SS, 316LSS, 321SS, 347SS, carbon steel, titanium, copper