司达行于1991年在香港成立，专业供应欧美原产密封件，从客户需求出发，以坚持发展密封件专业， 成为市场最佳选择为质量方针，为顾客提供选型导向、设计建议、安装指导、使用说明、故障排除等服务。 司达行代理产品有英国赫来特(HALLITE)液压密封件、奥地利DMH的密封件加工中心和原材料、意大利伽匹(GAPI)O形圈、土耳其KASTAS液压气动密封件及意大利FP骨架油封，加上其他著名品牌的现货库存品种超过5万项，数量超过2千万件。至今在整个大中华地区合共营运20家公司，员工超过200多人。 司达行于2002年引进奥地利DMH公司的密封件加工中心SEAL MASTER，并开始在区内推广有关设备及材料，至今在大中华市场、南韩及东南亚地区售出超过60台设备，最大加工直径1.5米。DMH和司达行在香港合资的司玛士达亚太有限公司于2010年11月份在香港成立，对亚太区内客户提供即时供货服务，并且在广州和宁波设立技术支援及培训中心，提升服务品质。 司达行以独立的经营概念作市场定位，不作恶性竞争，以客户的最大利益作为业务考虑，发展简单有效的合作关系，以大自然物竞天择的原则作为争取市场手法，构成对市场的吸引力。巨大的现货库存量，配合人员对行业及产品的经验，能为用户彻底解决每项密封问题，建立稳健、可靠、正派、守信的公司形象。
2016年3月，司达行获得香港民航处颁发的零部件制造批准书（HPMA），成为首家能够进入航空供应链的香港制造商。由于HPMA的申请门槛十分高, 整个申请过程历时差不多三年。是次通过民航处批准的零部件，是一款安装于民航客机机舱洗手间内的防虹吸阀的密封圈，可安装于中国内地、香港和澳门注册的飞机内。 2017年6月司达行取得航空工业品质管理系统认证，包括AS9100, AS9120 及ISO9001。这表示司达行的管理系统、产品设计、生产过程和质量保证都达到国际航空工业水平。 司达行致力研发和生产品质好、性价比高的航空零部件，盼望能为大中华的航空零部件市场提供更多和更好的选择。公司也在考虑为一些不影响适航安全的产品申请HPMA。 有关未来的发展动向，司达行正在建立一个ISO/IEC17025实验室，方便日后进行各种产品研发和质量检测的工作。此外，司达行也在计划申请美国联邦航空管理局(FAA)HPMA，从而扩展美国的航空市场
SEALTECH was founded in 1991 in Hong Kong specialized in supplying Seals and O-rings originally manufactured from Europe and America. Our mission and objectives are customer satisfaction and quality priority. We are aiming at being the top-class seals specialist in the region as well as the best and large selection of O-rings in the market. We supply O-rings, seals with our total sealing solution. Our services are including customer consultation for choosing the right seals, seals design suggestion, instruction for installation and usage and troubleshooting. We are currently qualified as the HPMA by Civil Aviation Department, The Government of the Hong Kong Special Administrative Region and distributor for HALLITE from The UK, DMH from Austria, GAPIand FP from Italy, and KASTAS from Turkey. Sealtech currently holds stock of more than 50,000 items including hydraulic seals, pneumatic seals,O-rings, oil seals and machine seals. Up to date, Sealtech has 20 branches in Great China with more than 200 staffs. Our large volume of stock ensures we stay competitive for all enquiries, no matter how large of small. In 2002, DMH seals machine known as Seal Master was first introduced to Sealtech Group. Until now, there are more than 60 machines are being installed where the largest diameter of seals could be manufactured up to 1500mm. DMH and Sealtech established a joint venture called- ‘Seal Master Asia Pacific Limited (SMAP)’ in November 2010 in Hong Kong. It aims to provide Just-In-Time services to customers in Asia Pacific by setting up technical support and training centres in Guangzhou and Ningbo, Mainland China to provide better services to customers. Our market positioning is to be the leader of the industry. We encourage benign competition. Interest of our customers to be our business focus. And a long-term partnership relationship with our customers is our company policy. Sealtech has built up its large inventory on top of our competency personnel to the industry. We are the industry partner for solving any seals’ problem.We are a stable, reliable, decent, trustworthy corporate.
In March 2016, Sealtech.com Aviation Seals Mfg. Ltd (SCAS) successfully obtained the Parts Manufacturing Approval (HPMA) issued by the Hong Kong Civil Aviation Department (HKCAD) and became the first Hong Kong manufacturer that can be able to enter the aviation supply chain. Due to the high threshold for HPMA applications, the entire application process lasted almost three years. The part approved by the HKCAD is an O-ring placed in an anti-siphon valve installed in a toilet of civil aircraft cabin. The O-ring can be installed in any aircrafts that registered in China, Hong Kong and Macau. In June 2017, SCAS obtained the Aviation Industry Quality Management System Certification, included AS9100, AS9120 and ISO9001. This means that the management system, product design, production process and quality assurance of SCAS has reached the international level of aviation industry. In order to provide more and better choices for aviation industry in the Greater China region, SCAS is committed to develop and produce high cost performance HPMA parts. Moreover, SCAS is applying HPMA for non-critical parts as well. Regarding future developments, SCAS is setting up an ISO/IEC17025 laboratory to facilitate product development and quality testing. In addition, SCAS is planning to apply for the US Federal Aviation Administration (FAA) HPMA to expand the US aviation market.