Piping connected to machinery equipment

Dear Friends

API RECOMMENDED PRACTICE 686 in Chapter 6 (Piping)states in Para. 2.10.2 "Piping vents and drains shall be located in breakout spools on the inlet and outlet piping to the machine". Furthermore,Pressure measurement connections required with isolation valves are to be installed in spool as shown in Fig B3. My question is why those vents, drains or pressure connections have to be in spool and not tapped directly in the pipe (by installing boss, nipple, isolation valve and then the pressure gauge)

Thanks

Khaled Received on Fri Apr 27 16:32:00 2007