MIRAB at a glance
MIRAB was founded in 1979 in Tehran and during the early activity in the old works produced special and taylor made industrial parts for railway infrastructure, automobile industries, water supply and energy sectors.
MIRAB spread its wings technologically in 1980′ s with the advent of water supply, wastewater treatment and fire protection industries, with the introduction of Industrial Valves and the original product lines were abandoned.
Having increased in production, MIRAB transferred its operation to Shams-Abad Industrial Zone which could guarantee future development.
With more than 40 years’ experience, as well as focusing on constant research in high performance
MIRAB HEAT EXCHANGER
along with the competitiveness of the quality and price, MIRAB has developed significant innovative technologies in design and fabrication of AIR-COOLED Heat Exchanger (ACHE) and finned tubes and MIRAB HEAT EXCHANGER Company has been established in 2019 which can offer product to power generation plant industries now.
On a more technical note, the complete service starting from thermal and mechanical engineering to complete manufacture, including design, inspection and quality control and all manufacturing segments such as FIN-Forming, Sub-Assembly and Brazing, Brazing Investigation and Evaluation, Assembly and Welding, Weld NDT, Pneumatic and Final Leak Test, Top-Level Assembly, Cleaning and Shipment guarantees MIRAB supplies for the best performance and efficiency.
Fin-Forming
The forming of fins is a serious technological challenge. If you are seeking for a high-accuracy fin production, solid performance, combined with the
terms of economics and high speed production the most modern machine shall be employed in order to ensure the quality of forming of coated aluminum strip.
Sub-Assembly and Brazing
Fin brazing of single row heat exchanger tubes is performed in a brazing furnace with controlled protective atmosphere (Typically Nitrogen). Typical brazing furnaces operate in a continuous way whereas furnace with batch operation are only used for special application with low rate production aspects.
In order to achieve Word Class brazing quality and specification, all process steps such as drying flux
suspension, pre-heating, flux and aluminum brazing alloy melting, brazing, static cooling down, controlled cooling down and forced cooling down shall be designed and performed in accordance with Word Class Engineering Concepts and High-Precision Brazing Time-Temperature Chart, paired with High-Tech CAB Furnace.
Brazing Quality Control and Inspection
The finned tube will be inspected non-destructive and on randomly selected Fin/ Tube destructive as follows, in order to insure that quality and performance of brazing completely meets concepts of engineering documents and technologies:
a) Visual inspection of fin bonding;
b) Visual examination of fin shape;
c) Spatula test;
d) Fin pull test;
e) Fin/ Tube burst test;
f) Fin/ Tube cross section visual examination after machining;
e) Metallographic analysis in order to perform following evaluations and investigations:
– Dimension of brazed fillet;
– Dimension and distribution of shrinkage;
– De-lamination of bonding;
– Si-Al phase distribution;
– Thickness of inter-diffusion zone between silicon and aluminum;
– Thickness of brittle Fe-Al inter-diffusion zone.
Tube bundle Assembly and Welding
There are many reasons involved why we can certify the execution of all Tube bundle assembly and welding in all respects of most stringent quantity and performances some of which are finest raw material, very modern welding machines, high-end equipment and facilities with a combination of reliable engineering knowledge, verified welding technologies and qualified personnel.
Although literally strict rules and regulations are imposed by quality control inspectors, each welder
Pneumatic and Final Leak Test
In order to investigate and evaluate welding quality Weld NDT such as visual test and liquid penetration test will be carried out before the pneumatic test.
All tube bundles are 100% pneumatically tested based on engineering specifications and procedures, particular attention is dedicated to final Pneumatic test of tube bundles as well.
operators and/or assembly technicians, in view of his necessary and required qualification level in employment category, are in charge of checking visually and dimensionally the component.
It goes without saying that all applicable welding techniques in pressure vessel manufacturing such as SMAW, GMAW and GTAW in related and defined welding positions are running in MIRAB HEAT EXCHANGER Weld Shop based on verified WPS(s)
by qualified welders.
Furthermore, during test and in compliance with QC test instructions, so accurate inspections and monitoring are there that they can ensure zero leakage of tube bundles when all Fin-Tubes and Base Tube-End Plate weldment are monitored individually.
Top level Assembly, Final Cleaning and Tube Bundles Shipment
Concluding the process is final cleaning step where all tube bundles are cautiously cleaned, coated, final assembled and fully protected from dust or dirt while end plates are immediately blocked. After this occurs, tube bundles packed in special packing frames are ready for shipment to the site.
