SIET SpA

SIET S.p.A. — whose full registered name is Società Informazioni Esperienze Termoidrauliche S.p.A. — is an independent Italian testing, calibration, and certification laboratory headquartered at Via Nino Bixio 27/C in Piacenza, Emilia-Romagna. Founded in 1983, the company has accumulated more than four decades of specialised experience in thermo-fluid-dynamic and mechanical testing of components and systems destined for energy-production plants, industrial process installations, and fluid-distribution networks. SIET also serves as an accredited calibration centre (laboratorio metrologico) and operates as an accredited product and management-system Certification Body, making it a rare single-source partner for testing, measurement traceability, and third-party conformity assessment. Its international recognition — including inspections by the U.S. Nuclear Regulatory Commission and collaborations with major global reactor developers — underlines its status as one of the world's most capable thermal-hydraulic experimental facilities.

The core laboratory testing service at SIET covers a wide range of industrial components subjected to thermo-fluid-dynamic and mechanical qualification regimes. Components routinely tested include industrial valves (valvole industriali), hydraulic disconnectors (disconnettori idraulici), thermostatic valves (valvole termostatiche), shell-and-tube and helical-coil heat exchangers (scambiatori di calore), piping and fittings (tubazioni e raccordi), sealing devices (dispositivi di tenuta), and automotive components. For heat exchangers, SIET performs characteristic-curve testing covering head-to-flow-rate, power-to-flow-rate, and efficiency-to-flow-rate relationships across water/water, water/steam, air/water, and air/oil configurations. Tests are conducted under prototypic fluid temperatures, pressures, and flow rates, with data used to validate thermal-performance models and to support component qualification and certification programmes.

The metrological and calibration division holds ACCREDIA accreditation (accreditation number 00124, scope LAT) under ISO/IEC 17025, providing traceable calibration services across a uniquely broad set of physical quantities: pressure, temperature, flow rate, dimensional quantities, electrical quantities, force and torque, mass, volume and density, acoustic noise, time, humidity, and velocity. The laboratory is listed in the Italian public-administration e-procurement portal (MePA), making its calibration services accessible to government and regulated-industry clients. For quantities beyond the core accredited scope, SIET additionally provides reference-traceable calibration services, ensuring that industrial customers can satisfy regulatory and quality-management requirements for their entire instrument fleet from a single supplier.

SIET is widely recognised as a world leader in experimental research for the nuclear power sector. The company operates high-pressure, high-temperature experimental loops — referred to as simulatori di impianti nucleari — capable of replicating the thermohydraulic conditions inside light-water and advanced reactors. Specific research capabilities include steam-separator testing, passive safety-system verification (circuiti a circolazione naturale), jet-pump performance mapping, rod-bundle (fascio di barre) heat-transfer experiments, and water-purification (potabilizzatore d'acqua) system development. A landmark project was the full-scale testing of NuScale Power's helical coil steam generator (HCSG) at SIET's Piacenza facility, conducted at prototypic operating conditions to validate thermal-performance codes and assess flow-induced vibration behaviour. SIET has also carried out ENEA-commissioned passive-cooling system tests for advanced Generation III+ reactors, working alongside ENEA's Nuclear Safety and Sustainability Division and Politecnico di Milano.

Beyond testing and calibration, SIET operates as a multi-scope Certification Body accredited by ACCREDIA under scheme PRD (product certification) and MS (management system certification). The certification division issues third-party product conformity certificates and management-system certificates, including in information-security management (ISO/IEC 27001) following a successful transition to the updated accreditation standard ISO/IEC 27006-1:2024. The combination of in-house test execution, traceable measurement, and independent certification under one roof allows SIET to support the full qualification lifecycle — from development prototype through regulatory submission — without requiring clients to engage multiple bodies.

SIET's engineering and training division leverages the technical-scientific competencies built over decades of experimental work. Services include design and supply of custom experimental plant and didactic test benches (banchi di prova didattici), thermo-fluid-dynamic computational analysis (calcoli termofluidodinamici), measurement-uncertainty evaluation, instrumentation management, and technical training courses. These offerings allow industrial clients and academic institutions to commission bespoke experimental infrastructure or to outsource complex modelling tasks to SIET's engineering team, extending the lab's value well beyond conventional testing services.

SIET holds ACCREDIA accreditation (number 00124) across four scopes — LAT (calibration), LAB (testing), PRD (product certification), and MS (management-system certification) — and is certified to ISO 9001 for its quality management system. The laboratory has undergone inspections by the U.S. Nuclear Regulatory Commission, attesting to the rigour of its test protocols and data-quality practices in safety-critical applications. Ownership by Italian national bodies including ENEA (the Italian National Agency for New Technologies, Energy and Sustainable Economic Development) further anchors SIET within the national and European energy-research ecosystem. With its combination of rare large-scale experimental loops, broad ACCREDIA accreditation, and more than 40 years of documented expertise, SIET S.p.A. represents a highly credible and technically authoritative testing partner for clients in the energy, industrial-process, nuclear, and advanced-engineering sectors.