Sealing arrangement for syringe

A syringe for use in a drug infusion system, the syringe comprising:

• a barrel having a tapered front end, a rear end, and a cylindrical wall defining an outer surface and an inner surface, the rear end of the barrel being open, and the front end of the barrel including an orifice;
• a plunger within the barrel, the plunger including a continuous contact surface at a front end of the plunger, a rear end of the plunger having an outer cylindrical surface including a tapered outer surface at the rear end of the plunger, a deflectable tab, a blind bore having an inner cylindrical wall portion defining a continuous even cylindrical surface extending from an entrance of the blind bore to a plunger seat, a front seal gland extending circumferentially around the plunger between the front end of the plunger and the rear end of the plunger, and a rear seal gland extending circumferentially around the plunger between the front seal gland and the rear end of the plunger, the tapered outer surface increasing in diameter from a surface of the rear seal gland to the rear end of the plunger;
• a front o-ring positioned in the front seal gland, and creating a gas-tight seal between the inner surface of the barrel and the plunger;
• and
• wherein the front o-ring is sized to maintain the gas tight seal through a temperature change within a temperature range of −25° C. to 40° C.