SNLEE manufactures pump in sub which is designed to facilitate ease access for pumping fluids into the well or bleeding of lubricator pressure. It is normally placed below the Wireline Valve and above the Pump head.
The Pump-In Sub gives you a 2 in. 1502 port to bleed-off well gases and fluids from your pressure control stack. It also gives you an inlet to equalize equipment and add helpful fluids that can change viscosity or remove damaging crystal formations from your equipment.