FIELD: medicine.SUBSTANCE: group of inventions relates to medical equipment, namely to needleless access connectors. Needleless access connector with positive pressure displacement includes case with female Luer connector base with male Luer connector and valve element with proximal end, which creates sealing in case, membrane element and distal end, fastened to base for membrane element ventilation. Base and valve element are connected to each other to create unit, the largest diameter of which is smaller than internal diameter of case. Base contains Y-shaped ventilation channel from membrane element to distal end of base. Y-shaped ventilation channel contains triangle-shaped deviations. In the second version needleless access connector with positive pressure displacement includes case, which has first Luer connector at proximal end base, which has second Luer connector at distal end and valve element with proximal end, which creates sealing in first Luer connector, and distal end, which is fastened to base in such a way that surface of valve element is located in fact at the same level with base surface. Valve element contains membrane element, separated from channel for flowing medium stream between first Luer connector and second Luer connector, and valve element and base determine air channel, connecting membrane element with atmosphere. In accordance with the third version of implementation of needleless access connector with positive pressure displacement distal end of valve element is fastened to proximal end of base by means of lockable latch. Air channel from membrane element of valve element contains single hole, axially located inside base section, forming part of latch. Method of assembling needleless access connector includes stages of fixation of distal end of valve element to proximal end of base, creating second sealing between valve element and base, separating membrane element from channel for flowing medium stream between first and second Luer co
