압력 에너지화

하중 제어를 위한 단면 및 벽 두께 설계

내부, 외부 및 축 방향 압력에 사용 가능

재료 범위 (합금 X750, 718, Waspaloy 및 기타 이국적인 금속)

도금 및 코팅: 은, 금, PTFE (기타 가능)

온도 범위: -273°C에서 730°C (-460°F에서 1350°F)까지

압력 범위: 중간 진공에서 2,000 bar (29,008 PSI)까지

누출 범위: 약 ≤ 25 cc/min @ 50 psig 질소 인치당 직경에서 ≤ 1 x 10-4 std.cc/sec 공기. 실제 누출 속도는 씰 하중, 표면 마감 및 표면 처리에 따라 달라집니다.

선택적 기능

마찰 저항 코팅 가능

맞춤형 형태 및 크기 가능

석유 및 가스:다운홀 드릴링/MWD

산업용 터빈:연료 시스템/노즐

밸브: 본체/보넷, 백 시트 씰링

항공우주/우주:터보펌프, 연료 시스템, 노즐/인젝터, 극저온

자동차:터보차저, 배기

초록:

산업의 급속한 발전으로 인해 오토바이, 자동차, 중장비 트럭, 기계 및 장비와 같은 분야에서 가스의 수요와 공급이 급격히 증가했습니다. 중장비 트럭에서 가스를 사용하기 위해서는 안전성과 효율성을 달성하고 운전의 편안함과 안전성을 보장해야 합니다. 따라서 이 기사는 중장비 트럭 가스 출구에서 금속 V-링의 적용을 소개하며, 가스 출구에서 V-링의 설계, 제조 재료, 제조 공정 및 적용 원리를 포함합니다. 동시에 V-링의 성능을 테스트하고 분석하여 중장비 트럭 가스 시스템에서의 우수한 성능을 입증하고, 산업에 더 많은 선택지를 제공합니다.

키워드:

메탈 V자형 링; 중량 트럭; 가스 시스템, 가스 배출구; 응용 프로그램

일, 소개

국가 환경 보호 정책의 점진적인 도입과 함께 물류 산업은 연료 절약 및 환경 보호를 달성하기 위해 LNG(액화 천연 가스)의 사용으로 점차 이동하고 있습니다. 동시에 물류 산업의 경쟁이 점점 치열해지고 있으며, 중량 트럭의 운영 안정성, 편안함 및 안전성은 제품에 대한 더 높은 요구 사항을 제기하고 있습니다. 그 결과, 중량 트럭 가스 수출의 안정성은 물류 산업에서 관심의 뜨거운 주제가 되었습니다. 이 문제를 해결하기 위해 금속 V-링이 중요한 솔루션이 되었으며 점점 더 많이 적용되고 있습니다.

이.금속 V-링의 설계 및 제조

메탈 V-링은 V자형 탄성체와 유사한 구조 형태를 가진 밀봉 구조 구성 요소입니다. 외부 힘이 링에 작용하거나 "V" 굽힘 각도가 변화할 때, V-링은 특정 범위 내에서 압력을 형성하고 이를 주변 밀봉 영역으로 전달합니다.

중형 트럭의 가스 시스템에서 V-링의 가장 중요한 점은 안정적이고 신뢰할 수 있어야 한다는 것입니다. 가스 시스템의 적용에서 V-링의 설계 및 제조는 신뢰할 수 있는 품질을 보장하기 위해 표준을 엄격히 준수해야 합니다.

V링의 디자인은 조립 과정에서 좋은 밀봉을 보장하기 위해 다양한 중형 트럭의 요구 사항에 따라 조정되어야 합니다.

금속 V-링을 제조할 때는 고품질 금속 재료를 사용해야 합니다. 일반적으로 아연 도금 강판, 스테인리스 강판, 경질 알루미늄, 황동, 티타늄 합금 등의 재료를 사용할 수 있습니다. 그 중 316L 스테인리스 스틸은 우수한 내식성을 가지고 있으며 화학, 항공우주, 식품 및 제약 산업에 적합합니다. 또한 중형 트럭 가스 시스템의 일반적인 제조 재료이기도 합니다.

삼,금속 V-링의 제조 과정

금속 V-링의 제조 과정은 그 품질에 직접적인 영향을 미칩니다. 일반적으로 제조 과정에는 절단, 성형 및 성형과 같은 여러 단계가 포함됩니다.

1. 절단

금속 V-링 생산의 첫 번째 단계는 좋은 제조 재료를 선택하는 것입니다. 그런 다음, 다양한 요구 사항과 장비 구조에 맞는 해당 금형을 개발하고, 절단을 위해 절단, 금형 개방 또는 슬리브 분해 방법을 사용합니다.

2. 형성

절단 후, 금속 판은 금형의 요구 사항에 따라 엄격하게 형성됩니다. 먼저, 보드의 중앙을 비우고 원형 링의 기본 모양을 형성하기 위해 정량적인 펀칭이 필요합니다. 그런 다음, 금형을 통해 가장자리를 구부리고 눌러 최종 "V" 개방 모양을 형성합니다.

3. 형성

소위 성형은 V-링의 추가 기계 가공을 의미하며, 이를 표준 형태와 크기로 만들고, 이후 가공, 열처리 및 표면 처리와 같은 과정을 통해 가공 및 보강하는 것을 말합니다.

네 번째,가스 수출에서 금속 V-링의 적용

금속 V-링은 주로 가스 시스템의 밀봉에 사용되며, 가스가 새지 않도록 보장하고 밀봉하기 어려운 상황에서 좋은 역할을 합니다.

응용 원리: V자형 링의 내부는 V자형이고 외부는 원형으로, 탄성 구조에 속합니다. 외부 압력이 V링에 작용할 때, V링은 수축하고 압력이 사라지면 원래 상태로 돌아갈 수 있습니다. 또한, 밸브와 결합하는 과정에서 V링은 밀봉의 신뢰성을 보장합니다.

오,성능 테스트 및 분석

중량 트럭 가스 시스템에서 금속 V-링의 성능을 검증하기 위해 성능 테스트가 수행되었습니다. 실험 테스트 결과 금속 V-링은 우수한 신뢰성과 안정성을 가지고 있으며, 여러 번의 압축 및 감압 과정에서도 지속적으로 밀봉 성능을 유지할 수 있습니다. 또한, 압력을 견디는 능력이 상대적으로 강하며, 고강도 압력에서도 밀도를 보장할 수 있습니다.

육,결론 및 전망

중량 트럭 가스 시스템에서 금속 V-링의 적용은 중요한 기술이며, 그 신뢰성과 안정성이 검증되었습니다. 앞으로 산업 발전과 기술 진보에 따라 이 기술은 생산 품질을 더욱 향상시키고 전체 차량의 신뢰성과 안전성을 개선할 것입니다.

고급 생물 의학 밀봉의 새로운 영역을 열다! 상하이 라이도(Spring-Reinforced Metal C-형 밀봉 링)가 의료 장비의 신뢰성을 재구성하다.

생명 의학 분야에서 고급 의료 장비의 모든 정밀한 작동은 환자의 생명, 건강 및 치료 효과에 매우 중요합니다. 상하이Raido's painstakingly developed spring - reinforced금/은 도금된 금속 C자형 밀봉 링이상적인 선택으로 떠올랐습니다. 고급 밀봉 생물 의학에서 그들의 뛰어난 성능. 고급 맞춤형의료 CT 시스템및 기타고급 의료 응용 프로그램, 그들은 엄격한 요구 사항을 충족하고 장비의 안정적인 작동을 보장합니다.

Our스프링 - 보강된 금속 C자형 밀봉 링 자랑하는 네 가지 핵심 장점. 그들의고온저항력이 뛰어나 극한 온도에서 신뢰할 수 있는 작동을 가능하게 합니다.최대 750°C. Whether in고온 - 온도 장기 운영에 의해 생성된 환경CT 장비 or고온 - 온도 양성자 치료 시스템의 조건으로, 그들은 항상 밀봉 성능을 유지하고 안정적인 장비 작동을 보장할 수 있습니다.고압 저항동일하게 인상적이며 최대 1500 바, 견고하고 신뢰할 수 있는 밀폐를 제공하여 CT 장비 under 고압조건, 장비 작동에 대한 모든 우려를 제거합니다. 내식성 또한 과소평가할 수 없습니다. 특수 내식성 재료로 제작되었으며 처리되었습니다.금/은 도금, 그들은 여전히 의료 장비에서 일반적으로 발견되는 산과 알칼리와 같은 가혹한 화학 환경에서 오랜 시간 동안 사용될 수 있으며, 장비 유지 관리 비용과 교체 빈도를 크게 줄입니다. 초고진공 밀봉 성능은 하이라이트입니다. 뛰어난 누출률 1×10⁻¹⁰ Pa·m³/s 이하, 그들은 극도로 높은 정밀도와 안정성을 유지할 수 있습니다.초고진공 응용 프로그램, 양성자 치료 시스템의 가속기와 같은 주요 구성 요소를 위한 안정적이고 신뢰할 수 있는 작업 환경을 조성하여,X - 선관, 그리고 CT 이미징 장비의 탐지기I'm sorry, but it seems that there is no text provided for translation. Please provide the text you would like me to translate into Korean.

이 밀봉 링은 생물 의학 분야에서 광범위한 응용 프로그램을 가지고 있습니다. 양성자 치료 시스템의 경우, 이는 가속기 및 주요 구성 요소의 정확성을 보장하는 데 핵심이며, 양성자 빔의 정밀한 전송 및 초점을 보장하고 암 치료의 효과를 향상시키는 데 도움을 줍니다. InCT 이미징 장비, 그것은 주요 구성 요소의 신뢰성을 효과적으로 향상시킵니다.X - 선관 및 감지기는 외부 간섭을 줄이고 이미징을 더 선명하게 하며 진단을 더 정확하게 만듭니다. 또한, 이는 또한 적합합니다.고급 의료 장비 such as MRI 시스템 and방사선 영상 도구. 외부 자기장 간섭을 저항하거나 액체 누수를 방지하는 것과 관계없이, 그것은 쉽게 처리할 수 있으며, 밀봉 요구 사항을 완전히 충족합니다.고급 의료 장비.

상하이 라이도는 항상 혁신에 의해 추진되어 왔으며 생물 의학 분야에 더 나은 밀봉 솔루션을 제공하기 위해 최선을 다하고 있습니다. 우리의 선택은 스프링 - 보강된 금속 C자형 밀봉 링 의료 장비의 신뢰성과 안정성을 보호하기로 선택하는 것을 의미합니다. 생명 의학 분야에서 밝은 미래를 만들기 위해 함께 손을 잡읍시다!

Stainless steel 316L metal O-rings are critical sealing components in melt filters. Their application is highly compatible with the process characteristics and operating requirements of melt filtration, playing an irreplaceable role in ensuring stable equipment operation, filtration efficiency, and product quality. This article provides a detailed analysis from the aspects of application background, core functions, compatibility analysis, practical application scenarios, and precautions: 

## I. Application Background: Operating Characteristics and Sealing Requirements of Melt Filters  

Melt filters are widely used in industries such as plastics, chemical fibers, rubber, food, and pharmaceuticals. They are primarily used to filter impurities, gel particles, or unmelted substances from molten materials (e.g., polymer melts, resins, food melts) to ensure the quality of subsequent processing (e.g., spinning, film extrusion, injection molding). Their core operating characteristics impose stringent requirements on sealing components: 

1. **High-temperature environment**: Melt temperatures typically range from 150°C to 400°C (e.g., polyester melts at approximately 280–300°C, nylon melts at 240–260°C), with some engineering plastic melts reaching even higher temperatures. 

2. **High-pressure conditions**: Materials must maintain a certain pressure (usually 0.5–3 MPa) during filtration to drive the melt through the filter medium, avoiding pressure fluctuations that could destabilize flow rates. 

3. **Medium properties**: Melts are mostly viscous polymer materials, some containing trace corrosive additives (e.g., antioxidants, flame retardants). Additionally, sealing materials must not contaminate the melt (especially in food and pharmaceutical fields). 

4. **Frequent disassembly needs**: Filters require regular replacement of filter elements. Sealing components must withstand repeated mechanical stress from disassembly and quickly restore reliable sealing after each operation. 

## II. Core Functions of Stainless steel 316L metal O-rings  

In melt filters, Stainless steel 316L metal O-rings are mainly used for static sealing of critical interfaces such as **filter body and end cover, filter cavity and flange, and inlet/outlet joints**. Their core functions include: 

1. **Preventing melt leakage**: Through rigid metal sealing and interference fit, they block high-temperature, high-pressure melt from seeping through sealing gaps, avoiding material waste, equipment contamination, and safety hazards (e.g., burns from contact with high-temperature melt). 

2. **Ensuring stable filtration pressure**: Seal failure can cause pressure loss, affecting melt flow rate through the filter medium and filtration efficiency. The high strength and deformation resistance of stainless steel O-rings maintain stable system pressure. 

3. **Avoiding medium contamination**: Stainless steel (e.g., 316L) has excellent chemical inertness, does not react with melts, and does not release impurities at high temperatures, meeting cleanliness requirements in food, pharmaceutical, and other fields. 

4. **Adapting to frequent maintenance**: Compared to rubber or non-metallic seals, stainless steel O-rings offer better wear resistance and fatigue resistance, retaining sealing performance after multiple disassembly cycles, thus reducing maintenance frequency and costs. 

## III. Compatibility Analysis of Stainless steel 316L metal O-rings  

### 1. Material Compatibility: Meeting High-Temperature and Corrosion Resistance Needs  

- **High-temperature stability**: Commonly used 304 and 316 stainless steels can operate stably below 400°C for long periods. Their melting points (1300–1400°C) are much higher than the operating temperatures of melt filters, preventing softening, aging, or failure due to high temperatures (rubber seals typically age above 200°C and cannot withstand long-term high temperatures). 

- **Corrosion resistance**: 316 stainless steel, containing molybdenum, exhibits stronger resistance to trace acidic/alkaline additives, moisture, or residual solvents in melts. It is particularly suitable for filtering engineering plastic melts with corrosive components (e.g., PVC, fluoropolymers). 

### 2. Structural and Sealing Principle Compatibility: Addressing High Pressure and Surface Defects 

- **Interference sealing of solid structure**: Stainless steel 316L metal O-rings have a solid circular cross-section. During installation, they form an interference fit with the seal groove, undergoing slight elastic deformation under preload to fill micro-scratches and roughness defects on the sealing surface, creating an initial seal. As system pressure increases, melt pressure further compresses the O-ring, enhancing contact stress on the sealing surface (the "self-tightening seal effect"), which adapts to the high-pressure conditions of filters. 

- **Reliability of metal-to-metal sealing**: Compared to the "elastic sealing" of rubber O-rings, the "metal-to-metal" sealing of stainless steel O-rings is more resistant to extrusion—they are less likely to be damaged by extrusion through gaps under high pressure, making them particularly suitable for high-pressure sealing of large-diameter interfaces such as filter end covers. 

### 3. Mechanical Performance Compatibility: Withstanding Disassembly and Long-Term Use 

- **High strength and fatigue resistance**: Stainless steel has high tensile strength (approximately 520 MPa for 304 stainless steel), making it resistant to plastic deformation or fracture under repeated preload from disassembly. Its service life is much longer than that of non-metallic seals, reducing the cost of frequent replacements. 

- **Dimensional stability**: Stainless steel has a low thermal expansion coefficient (approximately 17×10⁻⁶/°C), resulting in minimal dimensional changes under high-temperature conditions. This maintains a stable interference fit, preventing increased sealing gaps and leakage due to thermal expansion and contraction. 

## IV. Practical Application Scenarios and Typical Cases  

1. **Plastic extrusion melt filters**:  

   In PE and PP film extrusion production lines, melt filters remove impurities from raw materials to ensure film transparency. Stainless steel O-rings are used for flange sealing between the filter housing and filter cartridge, withstanding melt temperatures of 200–300°C and pressures of 1–2 MPa to prevent production interruptions and material waste caused by melt leakage. 

2. **Chemical fiber spinning melt filters**:  

   In polyester and nylon spinning processes, melt purity directly affects yarn quality (e.g., breakage, fuzz). 316 stainless steel O-rings provide sealing for high-precision filters, not only withstanding 280°C temperatures but also avoiding melt contamination and spinning defects due to their clean, non-leaching properties. 

3. **Food-grade melt filters**:  

   In filtering food melts such as chocolate and syrup, compliance with FDA and other food contact standards is required. 304 stainless steel O-rings are non-toxic and non-migratory, and they withstand high-temperature disinfection (e.g., steam cleaning), adapting to hygiene requirements in the food industry. 

## V. Application Precautions  

1. **Sealing surface processing precision**: Stainless steel O-rings require high surface roughness of the sealing surface (typically Ra ≤ 1.6 μm). Surface scratches or depressions can cause seal failure, so the processing quality of seal grooves and flange surfaces must be ensured. 

2. **Preload control**: Insufficient preload leads to poor initial sealing, while excessive preload may cause over-deformation of the O-ring or damage to the sealing surface. 

3. **Material selection**: 304 stainless steel is suitable for general conditions, while 316L stainless steel is preferred for corrosive media or high cleanliness requirements. Avoid use in extremely corrosive environments containing sulfur or chlorine (special coatings or alloy materials may be required). 

4. **Installation and maintenance**: Avoid scratching the O-ring with sharp edges during installation. Regularly inspect the sealing surface for wear or corrosion, and replace the O-ring promptly if deformation or cracks are found. 

## VI. Conclusion  

FKM 고무 가스켓 

FKM (플루오로엘라스토머), 또한 플루오로고무로 알려져 있으며, 높은 플루오르 함량을 가진 합성 고무로, 플루오르화된 모노머로부터 공중합된 것입니다. 분자 구조 내의 많은 C-F 결합은 이 소재에 우수한 화학 저항성, 고온 저항성 및 노화 방지 특성을 부여합니다. 따라서 FKM 고무 가스켓은 엄격한 밀봉 성능 요구 사항이 있는 산업 현장에서 널리 사용됩니다. 다음은 핵심 성능, 전형적인 적용 시나리오, 장점 및 한계 측면에서의 자세한 소개입니다: 

## I. FKM 고무 가스켓의 핵심 성능 

FKM 고무의 분자 구조는 안정한 탄소-플루오르 결합에 의해 지배되며, 강한 화학적 비활성 및 우수한 물리적 및 기계적 특성을 특징으로 하며, 구체적으로 다음과 같이 나타납니다: 

### 1. 화학 저항성 

- **광범위한 중간 저항**: 대부분의 유기 용매(예: 케톤, 에스터, 에테르, 방향족 탄화수소), 강산(예: 황산, 질산), 강알칼리, 그리스, 유압유, 연료유(가솔린, 디젤, 항공유 포함) 및 부식성 가스(예: 염소, 플루오르)에 대해 강한 저항력을 가지고 있습니다. 팽창, 경화 또는 분해에 취약하지 않습니다. 

- **특수 환경에 대한 적응력**:강한 산화 환경(오존 및 과산화수소가 포함된 시나리오 등)에서 안정적인 성능을 유지할 수 있어, 강한 부식성 매체의 밀봉에 적용 가능한 몇 안 되는 고무 재료 중 하나입니다. 

### 2. 고온 저항 

- **장기 작동 온도 범위**:**-20℃~200℃** 범위에서 오랜 시간 동안 안정적으로 작동할 수 있습니다. 일부 고성능 등급(예: 퍼플루오로에테르 고무)은 260℃ 또는 심지어 300℃까지의 단기 온도를 견딜 수 있으며, 이는 일반 고무(예: EPDM 및 니트릴 고무)의 내열 한계를 훨씬 초과합니다. 

- **고온 안정성**: 고온 환경에서 부드럽게 하거나 흐르거나 분해되는 것은 쉽지 않으며, 낮은 압축 세트 비율(일반적으로 장기 고온에서 <30%)을 가지고 있어 밀봉 효과를 지속적으로 보장할 수 있습니다. 

### 3. 노화 방지 및 기후 저항 

- **노화 방지 능력**:산소, 오존, 자외선 및 기후 노화(예: 햇빛, 비 및 습도 변화)에 대한 강한 저항력을 가지고 있습니다. 장기간 사용 후 균열, 경화 또는 성능 저하가 발생하지 않으며, 서비스 수명이 일반 고무 개스킷보다 훨씬 깁니다. 

- **방사선 저항**: 일부 FKM 등급은 특정 방사선 저항성을 가지고 있으며, 저선량 방사선 환경에서 밀봉 요구에 사용할 수 있습니다. 

### 4. 물리적 및 기계적 특성 

- **밀봉 성능 및 탄력성**:좋은 탄성과 압축 복원력을 가지고 있어 밀봉면에 밀착할 수 있습니다. 진동이나 압력 변동이 있는 작업 조건에서도 신뢰할 수 있는 밀봉을 유지하고 누수 위험을 줄일 수 있습니다. 

- **마모 저항 및 강도**: 표면 경도가 적당하고, EPDM보다 마모 저항성이 우수하며, 인장 강도와 찢어짐 강도가 높아 특정 기계적 스트레스에 적응할 수 있습니다. 

## II. FKM 고무 가스켓의 전형적인 적용 시나리오 

위의 우수한 특성을 바탕으로, FKM 고무 가스켓은 밀봉 성능, 온도 저항 및 내식성에 대한 요구가 매우 높은 산업 분야에서 주로 사용됩니다: 

### 1. 석유화학 및 정밀화학 산업 

- 반응기, 저장 탱크, 파이프 플랜지 및 밸브의 밀봉에 사용되며, 다양한 부식성 매체(예: 산-염기 용액, 유기 용매, 촉매) 및 고온 작업 조건(예: 증류 및 중합 공정)에 적응합니다. 

- 석유 추출 장비(예: 시추 플랫폼 씰), 정유 공장 파이프라인 및 열교환기의 밀폐에 적응하여 원유, 중유 및 다양한 정제 부산물로 인한 부식에 저항합니다. 

### 2. 자동차 및 운송 

- 자동차 엔진 시스템:고온 부품(연료 분사 시스템, 기어박스 및 터보차저 등)의 밀봉에 사용되며, 엔진 오일, 고온 냉각수 및 연료로 인한 장기적인 침식에 견딥니다. 

- 신에너지 차량:배터리 냉각 시스템 및 모터 씰에 적응하고, 냉각제(예: 에틸렌 글리콜 용액) 및 고온 환경에 저항하며, 전압 저항 및 절연 요구 사항을 충족합니다. 

- 항공우주:항공기 엔진 연료 시스템, 유압 시스템 및 고온 파이프라인의 밀봉에 사용되며, 고고도 저온, 지상 고온 및 항공 연료와 같은 열악한 환경에 적응합니다. 

### 3. 기계 제조 및 산업 장비 

- 고온 기계:산업용 용광로, 건조기 및 증기 파이프라인용 밀봉 개스킷과 같이 지속적인 고온 및 열 사이클 충격을 견딥니다. 

- 유압 및 공압 시스템: 고압 유압 장비 및 공압 밸브의 밀봉에 사용되며, 유압유 및 압축 공기의 장기적인 영향에 저항하고, 고온에서 노화 및 고장이 발생하기 쉽지 않습니다. 

### 4. 전자 및 반도체 산업 

- 반도체 제조 장비:에칭 기계 및 이온 주입기의 밀봉 구성 요소와 같은, 불화수소(HF) 및 염소와 같은 부식성 가스를 견디고 고온 공정 환경을 견딥니다. 

- 전자 부품 밀봉:고온 전자 장비(예: 전원 모듈)의 방수 및 방진 밀봉에 사용되며, 장비 작동 중 고온 환경에 적응합니다. 

### 5. 식품 및 제약 산업 (특정 등급) 

- FDA(미국 식품의약국) 또는 USP(미국 약전) 기준을 충족하는 식품 등급 FKM 가스켓은 고온 멸균 장비(예: 증기 멸균기) 및 식품 가공 기계의 밀봉에 사용할 수 있습니다. 이들은 고온 증기 및 세정제의 부식에 견디며, 무독성이며, 유해 물질을 방출하지 않습니다. 

## III. FKM 고무 가스켓의 장점과 한계 

### 장점 

- **극도로 강한 화학 저항성**:대부분의 산, 알칼리, 용매 및 부식성 매체에 적응하며, 일반 고무보다 훨씬 넓은 적용 범위를 가집니다; 

- **탁월한 고온 저항성**: 200℃ 이상의 고온 산업 시나리오의 요구를 충족하며 오랜 시간 사용할 수 있습니다; 

- **노화 방지 및 긴 서비스 수명**:우수한 오존 및 자외선 저항력, 야외 또는 장기 사용 시 고장이 쉽지 않으며, 유지 관리 비용을 줄입니다; 

- **높은 밀봉 신뢰성**:좋은 탄성 및 압축 반발력으로 진동 및 압력 변동 조건에서 효과적인 밀폐를 유지할 수 있습니다. 

### 제한 사항 

- **제한된 저온 성능**:일반 FKM은 -20℃ 이하에서 경화되고 탄성을 잃는 경향이 있으며, 저온 밀봉 성능이 감소합니다(특수 저온 등급을 선택해야 하며, 이는 더 비쌉니다); 

- **높은 비용**: 원자재의 가격은 EPDM 및 니트릴 고무와 같은 범용 고무의 가격보다 훨씬 높아 저비용 및 비가혹한 작업 조건에서 밀봉 요구에 적합하지 않습니다; 

- **극성 용매에 대한 제한**:비교적 대부분의 매체에 저항력이 있지만, 몇 가지 강한 극성 용매(예: 저분자 케톤)에서 팽창 위험이 있을 수 있으므로 사전 호환성 테스트가 필요합니다; 

- **어려운 처리**: 가황 성형 공정은 높은 요구 사항이 있으며, 온도와 시간을 정밀하게 제어해야 합니다. 그렇지 않으면 성능에 영향을 미칠 수 있습니다. 

## IV. 선택 고려사항 

- **매체 호환성 확인**:사용 환경의 특정 매체(예: 산, 알칼리, 용매 유형)에 따라 제조업체가 제공하는 화학 저항 데이터 시트를 통해 호환성을 검증하거나 실제 테스트를 수행하십시오; 

- **온도 범위 일치**: 작업 조건의 장기 사용 온도와 단기 피크 온도를 명확히 하고, 온도 저항 수준에 해당하는 FKM 등급(예: 일반 FKM 또는 퍼플루오로에테르 고무)을 선택하십시오; 

- **저온 요구 사항 고려**:작업 조건이 저온 환경(예: -20℃ 이하)을 포함하는 경우, 개조된 저온 FKM 또는 퍼플루오로에테르 고무를 선택하여 가스켓의 경화 및 고장을 방지해야 합니다; 

- **비용과 성능 간의 균형**: 비고온 및 비강한 부식 환경에서는 비용 성능이 더 높은 고무(예: EPDM 및 니트릴 고무)를 선호할 수 있습니다. FKM은 열악한 작업 조건에 더 적합합니다. 

## 요약 

"화학 저항성, 고온 저항성 및 노화 방지"라는 세 가지 핵심 장점을 가진 FKM 고무 가스켓은 열악한 환경에 대처하기 위해 산업 밀봉 분야에서 "고급 솔루션"이 되었습니다. 이들은 석유화학, 자동차 및 반도체와 같은 높은 수요의 시나리오에서 특히 필수적입니다. 비용이 상대적으로 높지만, 그들의 초장기 서비스 수명과 신뢰할 수 있는 밀봉 성능은 장비 유지 관리의 위험을 크게 줄일 수 있어 고가 장비 밀봉을 위한 이상적인 선택입니다.

Raido Spring-Energized Hollow Metal ORings: Innovative Sealing Solution​

The newly launched spring-reinforced metal hollow Oring (also referred to as spring energized metal oring seals) by Raido is an innovative upgraded product developed based on the basic hollow metal oring seal. As a high-performance sealing component with unique structural design and outstanding functionality, it combines the advantages of traditional spring-energized hollow metal orings while achieving significant upgrades in sealing performance and working condition adaptability. Below is a comprehensive detailed introduction:​

1. Structural Features​

1.1 Core Structural Design​

The traditional spring-energized hollow metal oring is typically formed by bending a thin-walled seamless tube into a circular shape, with its two ends butt-welded to create a hollow interior. Raido’s upgraded product inherits this hollow structure while elevating it with a key innovation: high-performance elastomers (springs) are precisely installed in the inner cavity. Through the elastic support of the springs, the product forms a unique composite sealing structure of "metal skeleton + elastic compensation" — the metal hollow body serves as a rigid skeleton to ensure structural stability and resistance to extreme conditions, while the embedded springs provide continuous elastic force, addressing the limitations of traditional sealing components.​

1.2 Material Matching​

To maximize performance, Raido scientifically matches materials for the metal body and springs:​

• Metal body: Options include stainless steel, high-temperature alloys, and other materials, selected based on specific application requirements (e.g., corrosion resistance, high-temperature tolerance);​

• Springs: Made of special elastic alloys, ensuring excellent elasticity, fatigue resistance, and compatibility with the metal body to avoid issues like galvanic corrosion.​

2. Performance Advantages​

Building on the inherent strengths of traditional spring-energized hollow metal orings, Raido’s product achieves further breakthroughs in sealing efficiency and durability:​

2.1 High Elasticity and Superior Recovery Capacity​

Like traditional models, the embedded springs enable the oring to quickly rebound after significant compressive deformation, effectively compensating for wear, thermal deformation, or assembly errors that could degrade sealing performance. This ensures long-term stability even in dynamic working environments.​

2.2 Enhanced Sealing Reliability (Key Innovation)​

A standout advantage of Raido’s design is its ability to address sealing surface defects. When the sealing surface has minor scratches, unevenness, or other flaws, the springs generate continuous and uniform compensating force through their own elasticity. This force pushes the metal body to closely fit the sealing surface, effectively offsetting various defects on the surface, greatly reducing leakage risks, and delivering far better sealing performance than traditional hollow metal orings (which often fail to seal properly on imperfect surfaces).​

2.3 Strong High-Pressure Resistance​

The "metal skeleton + spring" structure significantly improves pressure collapse resistance. While traditional spring-energized hollow metal orings can handle pressures up to 40MPa (with some ultra-high-pressure models reaching over 100MPa), Raido’s product, through precise regulation of spring strength, can withstand extreme pressure conditions ranging from ultra-high vacuum to a maximum of over 200MPa. It maintains reliable sealing whether under internal or external pressure, making it suitable for ultra-high-pressure scenarios.​

2.4 Low Compression Set​

During long-term use, the product exhibits minimal compression set — the metal body retains its shape stability, and the springs do not lose elasticity due to fatigue. This ensures consistent sealing performance over time, reducing equipment maintenance and replacement costs caused by seal failure.​

2.5 Excellent Adaptability to Harsh Environments​

The metal body itself provides inherent resistance to high/low temperatures and corrosion, and when combined with the reinforcing effect of the springs, Raido’s oring excels in extreme environments:​

• It easily copes with temperature ranges from an ultra-low -196℃ (matching the low-temperature tolerance of traditional models for cryogenic media like liquid oxygen/liquid nitrogen) to an ultra-high temperature above 1000℃ (surpassing the high-temperature limit of some traditional models). It maintains stable sealing performance even during high-low temperature alternating cycles;​

• The corrosion-resistant metal body (e.g., stainless steel, high-temperature alloys) and compatible springs ensure resistance to strong corrosive media such as acids, alkalis, seawater, and radioactive substances, avoiding seal failure due to corrosion.​

3. Application Scenarios​

Leveraging its "extreme condition adaptability" — a core advantage of spring-energized hollow metal orings — Raido’s product is widely applicable in high-end fields with stringent sealing requirements, replacing ordinary rubber orings (poor resistance to high/low temperatures and corrosion) and simple metal orings (poor low-pressure sealing and no wear compensation). Key application areas include:​

3.1 Extreme Temperature Conditions​

• Low-temperature fields: Sealing for liquid oxygen/liquid nitrogen storage tanks, valves in LNG (liquefied natural gas) transmission pipelines, and low-temperature propellant systems in aerospace (temperatures as low as -196℃ to -270℃);​

• High-temperature fields: Sealing for boiler flue dampers, gas turbine shaft ends, automotive exhaust treatment systems, observation windows of industrial kilns, and high-temperature components in aerospace (temperatures up to 600℃ to over 1000℃).​

3.2 High/Low Pressure and Vacuum Conditions​

• High-pressure fields: Sealing for high-pressure cylinder pistons in hydraulic systems, high-pressure wellheads of oil drilling platforms, pump bodies of high-pressure water jets, and ultra-high-pressure valves in high-end equipment (pressures ranging from 20MPa to over 200MPa);​

• Vacuum fields: Sealing for semiconductor vacuum coating machines, vacuum drying oven doors, and aerospace vacuum chambers (vacuum degree up to 10⁻³Pa to 10⁻⁵Pa).​

3.3 Strong Corrosion Conditions​

• Chemical industry: Sealing for inlet/outlet valves of hydrochloric acid/sulfuric acid storage tanks, electroplating tanks, and pesticide production equipment;​

• Marine engineering: Sealing for seawater desalination equipment and hydraulic systems of offshore platforms (resistant to seawater corrosion);​

• Nuclear industry: Sealing for cooling systems of nuclear reactors (resistant to corrosion from radioactive media and high-temperature water);​

Metal Corrugated Reinforced PTFE envelope Gasket (TEFLON + STAINLESS STEEL) Product Description

The metal corrugated  reinforced PTFE envelope Gasket is a composite sealing component that combines the excellent chemical stability of polytetrafluoroethylene (TEFLON) and the high-strength support of stainless steel. With its unique "corrugated  structure + double-layer material" design, it becomes an ideal sealing solution for harsh working conditions in chemical, petroleum, pharmaceutical and other industries.

I. Core Materials: Scientific Integration of Dual Advantages

1、Surface Layer: Polytetrafluoroethylene (TEFLON)

As the direct contact layer of the sealing surface, PTFE material has the characteristic of "the king of corrosion resistance" — it can withstand an extreme temperature range from -200℃ to 260℃, and has no chemical reaction with strong acids (such as hydrochloric acid, sulfuric acid), strong alkalis (such as sodium hydroxide), strong oxidants and various organic solvents, completely solving the leakage problem of traditional gaskets caused by corrosion. At the same time, its ultra-low friction coefficient (only 0.04) can reduce the wear of the sealing surface, and its non-stick surface can avoid medium residue, meeting the cleanliness requirements of the food and pharmaceutical industries.

2、Base Material: Stainless Steel

The corrugated tooth base made of 304 or 316L stainless steel provides strong structural support for the product. The high-strength property of stainless steel (tensile strength ≥ 520MPa) can resist compressive deformation under high-pressure working conditions, while the corrugated tooth design compensates for minor unevenness of the flange surface through the "elastic buffer layer" effect. Even in scenarios with vibration or temperature fluctuation, it can still maintain stable sealing specific pressure, avoiding sealing failure caused by excessive rigidity of the base material.

II. Structural Design: Sealing Innovation of Corrugated Tooth Technology

The product adopts a composite structure of "stainless steel corrugated tooth base + PTFE coating". The peak-valley spacing of the corrugated  is precisely calculated (conventional tooth height: 0.2-0.5mm, tooth pitch: 1-3mm), forming multiple sealing cavities:

• When the flange bolts are tightened, the PTFE surface layer will produce "stepwise deformation" with the compression of the corrugated tooth structure. While filling the flange gap, the peak of the corrugated  forms line contact sealing with the flange surface, greatly improving the sealing specific pressure;

• The corrugated tooth structure of the stainless steel base can effectively disperse pressure, avoiding cold flow phenomenon of PTFE caused by excessive local stress, and prolonging the sealing life;

• The overall structure has both flexibility and rigidity, which can adapt to slight misalignment of the flange during installation, reducing installation difficulty.

III. Performance Characteristics: Core Advantages for Harsh Working Conditions

1.    Wide Temperature Range Sealing: Maintains stable sealing performance in the range of -200℃ (cryogenic working condition) to 260℃ (high-temperature working condition), suitable for scenarios such as refrigeration equipment and high-temperature reaction kettles;

2.       High-Pressure Resistance: Relying on the support of the stainless steel base, it can withstand a maximum working pressure of 30MPa, meeting the sealing needs of oil pipelines and high-pressure valves;

3.       Chemical Inertness: The PTFE surface layer has no corrosion or swelling to almost all chemical media (except molten alkali metals and chlorine trifluoride), suitable for chemical acid-base transportation pipelines;

4.       Long-Term Stability: The corrugated tooth structure reduces the cold flow and creep of PTFE, and the attenuation rate of sealing performance is less than 5% during long-term use (conventional service life: 3-5 years);

5.       Environmental Compliance: The material meets the standards of FDA (U.S. Food and Drug Administration) and RoHS (EU Restriction of Hazardous Substances), and can be used in fields such as food processing and drinking water treatment.

IV. Application Scenarios and Installation & Maintenance

(I) Typical Application Scenarios

• Chemical Industry: Flanges of acid-base storage tanks, feed inlets of reaction kettles, sealing end covers of chemical pumps;

• Petroleum Industry: Valves of oil transmission pipelines, manholes of crude oil storage tanks, sealing surfaces of oil-gas separators;

• Pharmaceutical Industry: Pharmaceutical liquid transmission pipelines, aseptic reaction tanks, sealing doors of freeze dryers;

• Energy Industry: Cooling systems of nuclear power plants, high-temperature steam pipelines of thermal power plants, production equipment for photovoltaic silicon materials.

(II) Installation and Maintenance Points

1. Before installation, clean the flange surface, remove oil stains, impurities and residues of old gaskets to avoid affecting the sealing effect;

        2.  When tightening the bolts, adopt the "diagonal step-by-step tightening" method to ensure uniform force on                    the gasket, avoiding damage to the PTFE surface layer due to local over-tightening;

        3.   If slight leakage occurs after long-term use, properly retighten the bolts (retightening torque shall not exceed                10% of the initial torque) without replacing the new gasket;

        4.  When the medium temperature exceeds 200℃, it is recommended to check the sealing status every 6 months to ensure no deformation of the corrugated tooth structure.

Through "material complementarity + structural innovation", the metal corrugated  reinforced PTFE envelope Gasket perfectly solves the pain point of traditional gaskets being "corrosion-resistant but not pressure-resistant, or pressure-resistant but not corrosion-resistant". It has become a high-end product with both reliability and adaptability in the modern industrial sealing field, providing safe and long-term sealing guarantees for various harsh working conditions.

PTFE (Polytetrafluoroethylene) envelope gaskets, also known as "PTFE encapsulated gaskets," are widely used in industrial sealing applications due to PTFE’s excellent chemical resistance, non-stick properties, and high-temperature stability. Their core design involves a PTFE outer "envelope" that encapsulates a softer, more compressible inner core (e.g., rubber, graphite, or fiber), combining PTFE’s corrosion resistance with the core’s sealing flexibility. 

Below is a detailed classification of PTFE envelope gaskets based on core material, PTFE envelope structure, and application-specific designs, along with their key characteristics and use cases.

 1. Classification by Inner Core Material  

The inner core is critical for achieving effective sealing (since pure PTFE is relatively rigid and prone to creep). Different core materials tailor the gasket’s compressibility, temperature resistance, and cost. 

 2. Classification by PTFE Envelope Structure  

The design of the PTFE outer layer affects the gasket’s sealing performance, installation ease, and resistance to "cold flow" (PTFE’s tendency to deform under pressure over time). 

 2.1 Full Envelope (Standard Type)  

Design: The PTFE sheet fully wraps the inner core, with the edges of the PTFE sealed (e.g., by heat welding or mechanical crimping) to prevent the core from leaking or being exposed to the medium. 

Advantages: Maximum protection of the core from corrosive fluids; suitable for full-face flange sealing. 

Limitation: Slightly lower compressibility than partial envelope types (due to full PTFE coverage). 

Use Case: Most industrial applications (chemical tanks, pipelines, pumps) where the medium is aggressive.

 2.2 Partial Envelope (Exposed Core Type)  

Design: The PTFE envelope covers only the sealing face (the area in contact with the flange) and the outer perimeter of the core; the inner bore (hole) of the gasket leaves the core partially exposed. 

Advantages: Higher compressibility (since less PTFE restricts the core’s deformation); easier to install in tight spaces. 

Limitation: The exposed core may be vulnerable to corrosion if the medium is highly aggressive. 

Use Case: Low-to-moderate corrosion environments (e.g., water treatment, HVAC systems) where compressibility is prioritized.

 2.3 Reinforced Envelope (Anti-Creep Type)  

Design: The PTFE envelope is reinforced with a thin layer of inert material (e.g., glass fiber, carbon fiber, or metal mesh) embedded in the PTFE matrix. 

Advantages: Significantly reduces PTFE cold flow and creep; maintains sealing integrity under long-term pressure or temperature cycles. 

Limitation: Higher cost than standard PTFE envelopes. 

Use Case: High-pressure/high-temperature applications (e.g., steam turbines, chemical reactors) where creep resistance is critical.

 3. Classification by Flange Type & Shape  

PTFE envelope gaskets are customized to match common flange designs, ensuring proper fit and sealing. 

 4. Specialized PTFE Envelope Gaskets  

These are engineered for niche industries with strict requirements (e.g., food safety, ultra-purity, or extreme environments). 

 4.1 FDA-Compliant Gaskets 

Design: Uses food-grade PTFE (e.g., PTFE meets FDA 21 CFR Part 177.1550) and inner cores (EPDM, Silicone) certified for food contact. 

Use Case: Food & beverage processing (dairy, brewing), pharmaceutical manufacturing (drug synthesis), and cosmetics production.

 4.2 High-Purity (Ultra-Clean) Gaskets  

Design: Made with virgin PTFE (no additives) and a core of high-purity graphite or PTFE foam. The envelope is polished to minimize particle shedding. 

Use Case: Semiconductor manufacturing (ultra-pure water systems), laboratory equipment, and biotech (cell culture reactors).

 4.3 Low-Temperature Gaskets  

Design: Inner core of low-temperature-resistant materials (e.g., silicone rubber, expanded PTFE) to maintain flexibility at -200°C to -50°C. 

Use Case: Cryogenic applications (LNG storage, liquid nitrogen pipelines).

 Summary of Key Selection Factors  

To choose the right PTFE envelope gasket, consider: 

1. Medium Properties: Corrosiveness (dictates PTFE grade and core material). 

2. Operating Conditions: Temperature (graphite core for high temp; silicone for low temp) and pressure (reinforced envelope for high pressure). 

3. Flange Type: Full-face vs. ring-type, standard vs. custom shape. 

4. Industry Standards: FDA, ASME, or ISO compliance (for regulated sectors like food/pharma). 

By aligning these factors with the classifications above, you can ensure optimal sealing performance and long service life.

Detailed Introduction to CIPP Type Double-Stage Single-Liner Metal Seal

1. Core Design and Performance Advantages of the Product

The CIPP Type Double-Stage Single-Liner Metal Seal has become a preferred sealing solution for extreme environments, thanks to its double-stage multi-layer metal composite structure. This structure fundamentally ensures the reliability and effectiveness of the seal under harsh conditions such as high temperature, ultra-high vacuum, and high-energy particle beam radiation, providing stable sealing support for high-demand industrial scenarios.

Its innovative proprietary knife-edge design is a major highlight. It not only accurately compensates for deviations in flange flatness, significantly improving installation convenience and ensuring a secure fit between the seal and the flange but also enhances sealing performance while simplifying the installation process. This makes the overall sealing operation more efficient and reliable, effectively reducing construction difficulty and time costs.

2. Groundbreaking Performance Compared with Traditional Seals

In terms of requirements for flange surface roughness, traditional seals usually require the flange surface roughness (Ra) to be controlled between 0.2-0.4, which imposes extremely high demands on flange machining accuracy. However, the CIPP Type Double-Stage Single-Liner Metal Seal launched by Sonkit breaks this limitation. Even if the flange surface Ra value is as high as 0.8-1.6, it can still achieve effective sealing. This greatly reduces the strict requirements for flange machining and lowers the early-stage machining costs of equipment.

At the same time, the knife-edge design of this seal also significantly reduces the demand for bolt preload. This advantage not only reduces the load on the bolts, extending their service life but also lowers the risk of seal failure caused by improper preload control during installation, further improving the stability of the sealing system.

In terms of leakage rate control, professional test verification shows that the leakage rate of the system using Sonkit's CIPP Type Double-Stage Single-Liner Metal Seal can be reduced to 1E-11 mbarl/s. This value far exceeds the original design requirement of 1E-10 mbarl/s, representing a qualitative leap in sealing performance and providing strong technical support for scenarios with high sealing requirements.

3. Typical Application Scenarios

With its outstanding performance, the CIPP Type Double-Stage Single-Liner Metal Seal is widely used in high-end fields with extremely strict sealing requirements, including:

1.       Fusion Reactors: As a key sealing component for fusion reactions, it needs to maintain sealing integrity under extreme working conditions to ensure the safe and stable operation of the reactor. The double-stage multi-layer structure and low leakage rate characteristics of this seal perfectly meet its requirements.

2.       Tokamak Devices: Tokamak devices have complex structures and require highly specialized and precise sealing solutions. This seal can adapt to their complex design while meeting special needs such as plasma confinement and neutron radiation resistance.

3.       Ultra-High Vacuum Applications: In ultra-high vacuum environments, seals need to maintain excellent sealing performance for a long time. The ultra-high vacuum adaptability of this product makes it an ideal choice for such applications.

4.       Laser and Radio Frequency Guidance Systems: These systems have strict requirements for the reliability and stability of seals. This seal can ensure that the system is not disturbed by the external environment during operation, safeguarding guidance accuracy and system performance.

4. Adaptation to Core Performance Requirements in Application Scenarios

1.       Adaptation to Extreme Operating Temperatures: The seal assembly can always maintain structural and sealing integrity within a wide temperature range of -50°C to 350°C. Whether it is material stability in low-temperature environments or deformation resistance in high-temperature environments, it can meet the usage requirements of extreme temperature scenarios.

2.       Guarantee for Plasma Confinement: In scenarios involving plasma confinement such as Tokamak devices, the seal can operate reliably in strong magnetic fields, effectively blocking external interference, ensuring plasma confinement effects, and providing a stable sealing environment for relevant experiments and production processes.

3.       Neutron Radiation Resistance: For scenarios such as fusion reactors that need to withstand neutron radiation, the sealing system can be exposed to neutron radiation environments for a long time without a decline in sealing performance or leakage caused by radiation, ensuring the long-term safe operation of equipment.

4.       Adaptation to Ultra-High Vacuum Environments: In ultra-high vacuum application scenarios, the seal has excellent vacuum retention capability and can maintain stable sealing performance in ultra-high vacuum conditions for a long time, avoiding the impact of seal failure on the vacuum environment.

5.       Adaptability to Complex Structures: Facing equipment with complex structures such as Tokamak devices, this seal, relying on its highly specialized design and precise manufacturing process, can perfectly adapt to the complex structure of the equipment, ensuring reliable sealing in complex installation environments.

A Tri-Clamp Gasket, also known as a tri-lobe gasket or sanitary gasket, is a type of sealing gasket specifically designed for sanitary connections. Below is a detailed introduction to it:

- **Structural Design**: A Tri-Clamp Gasket is typically used in conjunction with clamp fittings. Its assembly consists of two clamps, one gasket, and two pipe fittings. The gasket is placed between the connecting surfaces of the two pipe fittings, and the clamping force of the clamps compresses the gasket, thereby forming a tight, leak-free sealed connection.

- **Material Types**:

    - **EPDM (Ethylene Propylene Diene Monomer)**: It has an operating temperature range of -20°F to 300°F (approximately -29°C to 149°C). It offers excellent high-temperature resistance and good tolerance to animal and vegetable oils, ozone, steam, water, and oxygenated solvents. It is suitable for applications involving CIP (Clean-in-Place) disinfectants like Oxonia and ozonated water.

    - **FKM/Viton (Fluorocarbon Rubber)**: Its operating temperature range is -30°F to 400°F (approximately -34°C to 204°C). It has higher chemical resistance than most elastomers and excellent compatibility with strong acids. However, it is not recommended for continuous use in SIP (Sterilize-in-Place) procedures.

    - **PTFE/Teflon (Polytetrafluoroethylene)**: With an operating temperature range of -100°F to 500°F (approximately -73°C to 260°C), it boasts extremely strong chemical resistance. Nevertheless, it is not advisable for use in scenarios with frequent large temperature fluctuations, as it lacks memory and may experience a "cold flow" phenomenon.

    - **Silicone Rubber**: Its operating temperature range is -40°F to 450°F (approximately -40°C to 232°C). It exhibits chemical resistance to various common chemicals, including acids, alkalis, and steam, but has only average tolerance to oils.

- **Application Fields**: Tri-Clamp Gaskets are widely used in industries with extremely high sanitary requirements, such as the food, dairy, beverage, biotechnology, and pharmaceutical industries. They are used to seal clamp connections in sanitary piping systems, ensuring that the connections between pipes, valves, pumps, and other process equipment are sanitary, preventing product contamination, and guaranteeing product quality and safety.

- **Performance Advantages**:

    - **Good Sanitary Performance**: It has a smooth, non-porous surface without layered grooves or protrusions, which makes it difficult for bacteria to grow and dirt to accumulate. It complies with relevant sanitary standards and certifications such as FDA and USP Class VI.

    - **Reliable Sealing Performance**: Under the clamping force of the clamps, it can form an excellent sealing effect, effectively preventing the leakage of liquids or gases and ensuring the normal operation of the system.

    - **Easy Installation**: No special tools are required; installation and disassembly can be quickly completed using clamps, facilitating the maintenance and cleaning of equipment.