Company Overview and Professional Strength
Ningbo Donghang Sealing Co., LTD is a professional sealing product enterprise that integrates research and development, production, and sales. The company is located in Cixi City, Zhejiang Province (with its annual report registered in Yinzhou District, Ningbo City), and has over 20 years of experience in seal production. It is committed to providing customers with "zero leakage" flange connection sealing solutions, which can cope with harsh working conditions such as ultra-high temperature, ultra-high pressure, or strong corrosion.
The legal representative of the company is Gao Jiefeng. According to the 2021 annual report, the number of employees who pay social security is 5. It is a professional and efficient technology-based enterprise. The company participates in industry exhibitions all year round, with booth number E1922 in 2025 and E1776 in 2026.
Qualification certification and quality assurance
Ningbo Dongheng Seal Co., Ltd. has a sound quality management system and has passed:
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ISO9001Quality Management System Certification
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ISO14001Environmental management system certification
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ISO45001Occupational Health and Safety Management System Certification
In terms of industry qualifications, the company holds a special equipment testing form certificate and a seal GC professional certification (valid from 2024-2026). Its "non-metallic composite reinforced gasket" product complies with national standards, and the special equipment type test certificate number isTSX 77101002520230503。
Main product system
Basic sealing products
| Product Name | Characteristics and Applications |
|---|---|
| Metal wrapped gasket | Made by winding V-shaped/W-shaped stainless steel strips with non-metallic fillers, it has good elasticity and is suitable for static sealing parts such as pipelines, valves, heat exchangers, etc. with drastic temperature and pressure changes |
| Graphite composite gasket | Made from pure graphite board or high-strength graphite composite board, it has good compression resilience and high strength, and is commonly used in pressure vessels, pumps and other equipment |
| metal ring gasket | Made by CNC lathe machining solid metal, suitable for high temperature, high pressure, high corrosive working conditions, high pre tightening pressure |
| PTFE gasket/packing material | PTFE gaskets have strong corrosion resistance; Pan root packing is used for filling dynamic or static seals |
| Metal toothed pad | The surface has concentric tooth shaped grooves with good sealing performance, commonly used in high-pressure working conditions |
Special material products
For harsh working conditions such as ultra-high temperature, ultra-high pressure, or strong corrosion, the company has a stock of commonly used special materials that can be directly processed into the above-mentioned seals:
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Monel (Monel)
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Inconel
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Hastelloy alloy
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Titanium (Ti)
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Zirconium (Zr)
Industry Application Fields
The company's products are widely used inMechanical, chemical, metallurgical, electrical, marine, food, aerospace, pharmaceutical, electronic, automotiveWaiting for multiple industries.
6 technical advantages of PTFE gaskets compared to traditional sealing strips
PTFE (polytetrafluoroethylene) gasket is the core product in the company's PTFE gasket product line. Compared to traditional rubber seals, PTFE gaskets have the following significant advantages:
1. Excellent chemical corrosion resistance
PTFE gaskets can withstand almost all known chemical media (including strong acids, strong bases, aqua regia, and various organic solvents), with a pH range of 0-14. Traditional rubber sealing strips have limited performance in terms of oil and solvent resistance, and some materials are not resistant to acid and alkali corrosion.
2. A wider range of operating temperatures
PTFE gaskets can be used in-180 ℃ to+260 ℃Long term stable operation within a wide temperature range. The use temperature range of traditional rubber sealing strips is relatively narrow (EPDM rubber: -60 ℃~+150 ℃; chloroprene rubber: -30 ℃~+120 ℃), and PVC material is prone to brittleness at low temperatures.
3. Extremely low friction coefficient and non stickiness
PTFE has the lowest friction coefficient among known solid materials (about 0.04), extremely low surface tension, and is not easily adhered to any substance. Traditional rubber strips have a high coefficient of friction on the surface and are prone to adhesion with the contact surface.
4. Excellent anti-aging and service life
PTFE has excellent anti-aging performance, and is not susceptible to aging and embrittlement caused by ultraviolet, oxygen, ozone and other environmental factors. Traditional rubber sealing strips (especially PVC materials) are prone to plasticizer migration during use, which can become hard, brittle, and lose elasticity over time.
5. Good flexibility and compression resilience
PTFE gaskets that have undergone special processing have good flexibility, compression resilience, and creep resistance, and can be embedded in micro cracks and damaged areas to achieve repair and sealing. especially suitable forSealing of non-metallic devices (such as brittle materials such as glass, ceramics, graphite, plastics, etc.)。
6. Clean and non-toxic, suitable for the food and pharmaceutical industry
PTFE material is physiologically inert, non-toxic, and does not contaminate any substances it comes into contact with. It can be widely used in industries such as food, medicine, and electronics that require high cleanliness. Traditional low-end PVC products may contain halogens and heavy metal stabilizers, which are not conducive to environmental protection and hygiene requirements.
Summary of advantages and disadvantages comparison
| comparative dimension | PTFE gasket | Traditional sealing strip (rubber type) |
|---|---|---|
| Corrosion resistance | Resistant to almost all chemical media (pH 0-14) | Partially oil resistant, acid and alkali resistant, with limitations |
| Operating temperature | -180℃～+260℃ | -60 ℃~+150 ℃ (varies depending on the material) |
| coefficient of friction | Extremely low (0.04), with good self-lubricating properties | High and prone to adhesion |
| Aging resistance | Excellent, long lifespan | Easy to age, become hard and brittle |
| flexibility | Good, capable of embedding micro cracks | general |
| cleanliness | Non toxic, meets food and pharmaceutical grade requirements | Low end PVC containing halogens/heavy metals |
| Applicable fields | Chemical, pharmaceutical, food, electronics, aerospace, etc | Building doors and windows, automobiles, general machinery, etc |
Selection Recommendation
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Scenario for selecting PTFE gaskets: Strong corrosive media, extreme temperature conditions, clean environments for food and medicine, non-metallic brittle equipment connections
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Scenario for selecting traditional sealing stripsBuilding door and window sealing within the conventional temperature range, automotive waterproofing and dust prevention, general mechanical shock absorption and sound insulation
