Containing fluid leaks on additive pumps

An apparatus for an additive pump, comprising:

• an annular body with an outer surface having a distal section and a proximal section with a diameter that is smaller than the distal section and with threads for engaging with an additive pump, the annular body having a first through-bore forming a landing surface;
• and
• an elongate cylindrical body insertable into the first through-bore the annular body, the elongate cylindrical body having a second through-bore forming two open ends, the elongate cylindrical body having a shoulder between the two open ends, an annular detent spaced longitudinally apart from the shoulder, and annular grooves, one found on the shoulder and two others found on either side of the shoulder and spaced longitudinally apart from the shoulder by an amount that is greater than longitudinal spacing of the annular detent from the shoulder,
• wherein a part of the elongate cylindrical body with one of the annular grooves extends outside of the distal section with the elongate cylindrical body in contact with the landing surface.