Service manifold and special elbow for tank blanketing and venting valves

A service manifold comprising:

• a substantially linear main pipe having an entry and an exit at opposite ends thereof and an auxiliary pipe extending internally into said main pipe intermediate of said entry and said exit, said auxiliary pipe having a 90.degree. bend forming an inner arc and an outer arc portion, a first end extending through an opening in the wall of said main pipe, said first end having a shank of enlarged outer diameter relative to the diameter of said inner and outer arc portion and forming a junction therewith fixedly engaged in said opening, said enlarged outer diameter serving to reduce the arc of the bend and allow for a tight seating of the elbow in said opening and a stop on said outer arc abutting said wall and aligned with the said junction of said enlarged outer diameter and said outer arc.