The metal spirally-wound gasket adopts high-quality SUS304 or SUS316 ("V" or "W"shape) metal strips, other alloy materials and some flexible materials like graphite, asbestos, PTE and non-asbestos, which are overlapped and wound spirally with each other. The metal strips are fixed on the initial and terminal ends by means of spot welding. The metal spirally-wound gasket has the best resilien ce among the semi-metal hermetic gaskets. Its structural density can be made subject to different locking forces. Also the internal and external steel rings can be used to control its maximum compaction. It's not demanding for the surface precision of the flange sealing surface contacting the spirally-wound gasket. It's especially applicable for such occasions as uneven load, slack joint, periodical changes of temperature and pressure, impact or vibration. It's an ideal static seal element for flange connection in valves, pumps, heat exchangers, towers, manholes,handholes and so on.
Application scope of spirally-wound gasket:
Sealing of flange connection in pipelines, valves, pressure containers, condensers, heat exchangers, towers, manholes, handholes and so on in such industries as petroleum, chemical engineering, metallurgy, electricity, shipping and machinery.
Type of metallic wrapping pad:
Type | Section shape | Code name | Thickness(mm) | | Basic wrapping pad |
| A | 3.2 | 4.5 | | Wrapping pad with inner ring |
| B |
| 4.5 | | Wrapping pad with outer ring |
| C |
| 4.5 | | Wrapping pad with inner and outer rings |
| D |
| 4.5 |
|
Structural material of metallic wrapping pad:
Filling | Steel band | Inner ring | Outer ring |
| Asbestos wrapping | SUS 304 | Carbon steel | Carbon steel |
| Graphite wrapping | SUS 316 | SUS 304 | SUS 304 |
| Teflon wrapping | SUS 316L | SUS 316 | SUS 316 |
|
| SUS 316L | SUS 316L |
| Filling | Temperature(ºC) | Max operating pressure(kg/cm2) |
| Asbestos wrapping | -200~550 | 250 |
| Graphite wrapping | -150~450 | 100 |
| Teflon wrapping | 240~260 | 100 |
The following table lists metallic materials for inner ring and wrapping:
Outer ring is often made from carbon steel subject to anti-corrosive treatment.
Flange type and form of wrapping pad:
Flange type | Spiral wound gasket form |
| Flat face flange(F.F) | Wrapping pad with outer ring only |
| Wrapping pad with inner and outer rings |
| Raised face flange(R.F) | Wrapping pad with outer ring only |
| Wrapping pad with inner and outer rings |
| Male and female flange(M & F) | Basic wrapping pad |
| Wrapping pad with inner ring only |
| Tongue and groove flange(T & F) | Basic wrapping pad |
| Wrapping pad with inner ring only |
| Flat and groove flange(F & G) | Basic wrapping pad |
| Wrapping pad with inner ring only |
Wrapping pad thickness tolerance:
Item | Thickness(mm) | Tolerances(mm) |
| Gasket thickness | 4.5, 3.2 | +0.2
-0.1 |
| Ring thickness | 3.0 | ±0.24 |
Key technical parameter of metallic wrapping pad:
Wrapping pad coefficient | m=2.5-4 |
| Wrapping pad service pressure | ≤25MPa |
| Wrapping pad service temperature | -196ºC-700ºC(Oxidizing medium no higher than 600ºC) |
| Wrapping pad minimum pretension specific pressure | y=68MPa |
The following table refers to tolerances for the diameter of wrapping pad (namely the nominal pipe diameters for the use of flange):
|
DIM(mm) | ANSI B16.5
BS1560(mm)
Mss sp-44 | API605 | Tolerances | Inner ring diameter
Pad inner diameter | <=600 | <=24" | >=26" and <=34" | ±0.5 | | >600 and <=800 | >24" and <=34 | >=36" and <=60" | ±0.9 | | >800 and <=1600 | >34" and <=60" |
| ±1.3 | | >1600 | >60" |
| ±1.6 | | Pad outer diameter | <=600 | <=24" | <=24" | ±0.9 | | >600 and <=160000 | >24" and <=60" |
| ±1.8 | | 1600 | >60" |
| ±2.2 | | Outer ring diameter |
|
| >1/2" and <=60" | ±0.9 | | <=600 | <=24" |
| 0-1.0 | | >600 and <=1000 | >24" and <=34" |
| 0-1.8 | | >1000 and <=1600 | >34" and <=60" |
| 0-2.2 |
|
Note: We also tailor products based on JIS, JPI or customer requirement
Ordering information: The following parameters should be specified during ordering for metallic wrapping pad
Example:
1. Type of metallic wrapping pad: A B C D
2. Flange standard: ASME B16.20
3. Pipe through diameter, pressure rating: 2"150Lbs
4. Material: inner ring SS316; metallic wrapping belt SS316; packing belt: graphite; outer ring; carbon steel
Product name | AISI | Hardness(HB/HV) | Temperature(°C) |
| 304 Stainless steel | 304 | 130~180 | -250~+550 |
| 316 Stainless steel | 316 | 130~180 | -100~+550 |
| 316L Stainless steel | 316L | 130~190 | -100~+550 |
Ningbo Gangtong Zheli Fasteners Co., Ltd is a manufacturer in China which mainly produces high strength fasteners and specializes in all kinds of hardwares. Founded in 2001, In the past ten years, it developed fast with its factory located in Ningbo Zhenhai Chemical industrial area and its headquarter /foreign sales department in Ningbo Jiangdong Eastern Business Centre. The factory now covers an area of approximately 15, 000 square meters, with monthly production capacity of 2000 tons. The company has its all-around research system, supply management, large-scale warehouse, metal fastener system, and advanced supply chain management technology with metal fasteners MRO-based integrated procurement distribution business, with annual sales over $15, 000, 000.
The company products consists of bolts & nuts assembled or separate, self tapping or drilling screws, lag screws, threaded rod or studs, washers, which are made from both carbon steel and stainless steel. The products are exported to North America, Europe, Australia, Russia, Southeast Asia and Middle East and are strictly conform with DIN, ANSI/IFI, JIS, BS, ISO, GB specification, which are applied to architectural steel structures, brigdes, oil pipeline, machinery equipment, furniture, vessel, railway.
The company is firmly carrying out the ISO9001: 2000 to every process of production, from raw material analysis, process inspection, to finally approve before shipment, we never stop focusing on achieving a super quality level. Quality is the life of enterprise, strengthening quality awareness, cultivating quality attitudes, standardizing quality behavior, setting up quality ethos is our direction to make our customers satisfied. Once defective products are found by our customers, we will follow strictly the 8D report and ultimately solve the problem and improves it.
The company always carry forward the spirit of "Employee is footstone, customer first, technique expert, quality first". We welcome all of you from all over the world to join us for the win-win business partnership and friendship, welcome to China, welcome to Gangtong Zheli Fasteners!
