In software engineering(machine learning) train means:
in machine learning (= the study of creating computer systems that can improve their own ability to carry out tasks by analyzing new data), to create or improve a computer representation of a system or process by supplying it with data.
Reference:
https://dictionary.cambridge.org/dictionary/english/train
Also check this website for suggested translations:
https://www.almaany.com/ar/dict/ar-en/train/

وحدة تسلسلية
خط مسلسل من العمليات

for LP separator only where Train 1 is completed while Train 2 and 3 will be completed before end of April بالنسبة لعازلة الغاز المسال فهو فقط عند اكتمال وحدة التسييل رقم 1 بينما وحدة التسييل رقم 2 و3 فمن المنتظر اكتمالهم قبل نهاية شهر ابريل

Also known as a liquefaction unit. In the context of the midstream oil & gas sector, a train consists of various components to process, purify, and convert natural gas to liquefied natural gas (LNG). They are called trains because of the sequential arrangement of the equipment used to process and liquefy natural gas.
https://content.next.westlaw.com/Glossary/PracticalLaw/Ia493...

وخط كبس واحد one compressor train:
https://www.arab-oil-naturalgas.com/natural-gas-compressor-s...

(Gas Treating. Units). ﺜم ﻴﻨﻘل اﻟﻐﺎز اﻟﻨﻘﻲ إﻟﯽ وﺤدات اﻟﺘﺴﻴﻴل. Liquefaction Units. و اﻟﺘﻲ. ﻴﻤﮐن ﺘﺼﻤﻴﻤﻬﺎ ﻟﺘﺴﻴﻴل. LNG.
https://www.researchgate.net/profile/Shuker-Sankor/publicati...

--------------------------------------------------
Note added at 2 hrs (2023-11-19 13:00:38 GMT)
--------------------------------------------------

plant=unit=train = وحدة/منظومة/محطة/خط تسييل
Natural gas is converted to a liquid in a liquefaction plant, or “Train”. An LNG Train performs four main processes: 1) Pretreatment. Remove dust and slug (water and condensate) along with hydrogen sulfide (H2S) and mercury (Hg).
https://cameronlng.com/lng-facility/lng-and-liquefaction/#:~...