What is the correct order of sequence for fittings surrounding a steam trap?

The correct order of sequence for fittings surrounding a steam trap is important for optimal operation and maintenance of the steam system. In the answer provided, starting with the isolation valve allows for easy maintenance and servicing of the steam trap without having to drain the entire system. Placing the strainer next ensures that any impurities or debris in the steam are filtered out before they can reach the steam trap, which helps prevent clogs and ensures efficient operation.

Following the strainer, a union is appropriate as it provides a means for connecting and disconnecting the steam trap from the piping system without cutting or disturbing the pipes. After the union, the steam trap is installed to allow for the automatic drainage of condensate while preventing the escape of steam. Lastly, including a possible check valve helps maintain the functioning of the steam trap by preventing backflow, which can disrupt the trap’s operation.

Overall, this sequence promotes efficiency, ease of maintenance, and the integrity of the steam system, making it the best choice among the options.