A device for delivering a medicament into the body of a patient by injection into or through the skin of a patient, comprising: a housing (110, 115) having a bottom surface adapted to contact the skin of a patient, and a top surface; an injection needle adapted for penetration of tissue, said needle having a lumen; a reservoir, disposed within said housing, comprised of a substantially rigid plate and a substantially flexible membrane bonded thereto, forming a chamber for containing said medicament, said reservoir having a body opening in said rigid plate, said body opening having a longitudinal axis, a reservoir end, a body end, and a reservoir port wherein said body opening is in fluid communication to said chamber via the reservoir port, and said body opening is in fluid communication to the lumen of the injection needle via a needle port disposed between said reservoir end and said body end of the body opening, wherein said reservoir is substantially cylindrical; a pressurizing system for pressurizing said chamber by compressing said membrane; and a valve disposed in said body opening having a reservoir seal for sealing said reservoir port and a body seal for sealing said body end of said body opening, and movable along said longitudinal axis, between a first and a second position within said body opening; characterized in that said valve is a soft member comprising a large diameter distal end including said body seal, a reduced diameter body extending from said distal end, and an enlarged proximal end extending from said reduced diameter body and including said reservoir seal; said body seal comprises radially projecting fins (225, 753, 1307, 1407, 1508, 1531) preventing microbial access to said body opening in said first position and said reservoir seal comprises detents or ribs (226, 754, 1307, 1407, 1506, 1532) sealing the medicament in the chamber in said first position; and the device further comprising a needle conduit having a manifold end and a needle port end, wherein the needle port end is in fluid communication with the needle port and the manifold end is in fluid communication with the lumen of the needle, and the manifold end is adapted to hold the needle. a housing (110, 115) having a bottom surface adapted to contact the skin of a patient, and a top surface; an injection needle adapted for penetration of tissue, said needle having a lumen; a reservoir, disposed within said housing, comprised of a substantially rigid plate and a substantially flexible membrane bonded thereto, forming a chamber for containing said medicament, said reservoir having a body opening in said rigid plate, said body opening having a longitudinal axis, a reservoir end, a body end, and a reservoir port wherein said body opening is in fluid communication to said chamber via the reservoir port, and said body opening is in fluid communication to the lumen of the injection needle via a needle port disposed between said reservoir end and said body end of the body opening, wherein said reservoir is substantially cylindrical; a pressurizing system for pressurizing said chamber by compressing said membrane; and a valve disposed in said body opening having a reservoir seal for sealing said reservoir port and a body seal for sealing said body end of said body opening, and movable along said longitudinal axis, between a first and a second position within said body opening; characterized in that said valve is a soft member comprising a large diameter distal end including said body seal, a reduced diameter body extending from said distal end, and an enlarged proximal end extending from said reduced diameter body and including said reservoir seal; said body seal comprises radially projecting fins (225, 753, 1307, 1407, 1508, 1531) preventing microbial access to said body opening in said first position and said reservoir seal comprises detents or ribs (226, 754, 1307, 1407, 1506, 1532) sealing the medicament in the chamber in said first position; and the device further comprising a needle conduit having a manifold end and a needle port end, wherein the needle port end is in fluid communication with the needle port and the manifold end is in fluid communication with the lumen of the needle, and the manifold end is adapted to hold the needle.