Top Equipment Vendors/suppliers for Oil and gas Industry

I am working on a study in which I need to identify top vendors/suppliers for the following equipments for oil and gas industry. If someone knows the top vendors and suppliers for all or any one equipment please can you tell me and why do you think they are the top supplier

Mass transfer columns

​Absorbers
​Adsorbers
Separators

Filters

Splitter (liquid-liquid separator)


Coalescer (Within 3 Phase Sep)

Flotation Units
Heat Exchangers


Air Cooled

Cryogenic

Shell & Tube

Plate (PCHE)

Plate-Fin
Heaters


Fired heaters

Indirect Fired Heaters

Direct Fired Heaters

Electric heaters

Waste heat recovery units


Regards

Coolwater