Founded in 1980 by Adelino da Silva Matos and Edite da Silva Costa Matos, CITERGAZ, headquartered in Albergaria-a-Velha, Aveiro was born from the company A. Silva Matos - Indústria Metalúrgica Lda, headquartered in Sever do Vouga. Initially, A. Silva Matos was dedicated to stainless steel constructions for the food industry. However, it evolved in other directions, thanks to the established strategy, later to be designated as A. SILVA MATOS, METALOMECÂNICA S.A. In 1989, A. Silva Matos, Metalomecânica SA, through a joint venture with CITERGAZ, SA (France), gave rise to CITERGAZ - Caldeiraria e Manutenção Lda. (Portugal), which was used to manufacture gas mini-tanks. . In 1990, CITERGAZ - Caldeiraria e Manutenção Lda. Started to produce liquid fuel tanks and pressure tanks. This year, A. Silva Matos, Metalomecânica S.A. is certified by IPQ, according to ISO 9002, becoming the 1st company in its sector to obtain such a distinction and, three years later, obtains TUV Sudwest certification. In 1994, CITERGAZ becomes a public limited company. In 1995, A. Silva Matos, Metalomecânica SA acquires the shares of CITERGAZ SA (France), which is now renamed CITERGAZ, Caldeiraria e Manutenção Lda .. Still during this year, Citergaz is certified by IPQ, according to ISO 9002. In 2003, CITERGAZ, Caldeiraria e Manutenção Lda. Made the transition from its Quality Management System to ISO 9001: 2000. In 2007, due to the creation of Holding A. Silva Matos SGPS., CITERGAZ becomes a public limited company again. In 2012, a restructuring of the company appears, and the implementation of a Quality Management System begins with the NP EN ISO 9001: 2008 Standard, independently from the Group. In August 2017, the transition to the new edition of the Quality standard, ISO 9001: 2015, was completed. This certification recognizes the organization's efforts to ensure the conformity of its products, the satisfaction of its customers and continuous improvement.