A pipe clamp for engaging around a circumferential joint between two axially adjacent combustion air pipes (20, 21) of an exhaust pipe system of a heating system, the pipe clamp having a contact ring for contacting circumferential surfaces of the two combustion air pipes and fixation means by means of which the contact ring can be braced around the combustion air pipes (20, 21), the contact ring having a first and a second free end portion (3, 4) for opening the contact ring for installation purposes, and an overlap section at the end of the first end portion overlapping a tongue at the end of the second end portion on the radial outside in the circumferential direction in the installed state, the overlap section overlapping the tongue in both axial directions (7, 8) in the installed state and having a contact surface (11, 12) on each of the two axial sides of the tongue in order to be supported on the outer circumferential surfaces of the combustion air pipes (20, 21) axially adjacent to the tongue on both sides of the joint by means of a respective contact surface (11, 12) characterized in that the fixation means have a buckle and a loop, each of which is assigned to a free end, the buckle and the loop comprising complementary locking means for locking the pipe clamp in different bracing positions, and that the loop extends substantially in the circumferential direction and that a first end of the loop is connected to the pipe clamp in the area of a free end portion of the pipe clamp and that the loop has an opposite locking end for being inserted into the buckle, wherein a deformation area, which is curved in the open state of the pipe clamp, is disposed between the two ends (29, 30), wherein the deformation area is elastically and radially deformable by applying a radial force, its curvature being at least partially reduced in the process, the locking end thus being movable away from the end which is connected to the pipe clamp when the deformation area is deformed. the contact ring having a first and a second free end portion (3, 4) for opening the contact ring for installation purposes, and an overlap section at the end of the first end portion overlapping a tongue at the end of the second end portion on the radial outside in the circumferential direction in the installed state, the overlap section overlapping the tongue in both axial directions (7, 8) in the installed state and having a contact surface (11, 12) on each of the two axial sides of the tongue in order to be supported on the outer circumferential surfaces of the combustion air pipes (20, 21) axially adjacent to the tongue on both sides of the joint by means of a respective contact surface (11, 12) characterized in that the fixation means have a buckle and a loop, each of which is assigned to a free end, the buckle and the loop comprising complementary locking means for locking the pipe clamp in different bracing positions, and that the loop extends substantially in the circumferential direction and that a first end of the loop is connected to the pipe clamp in the area of a free end portion of the pipe clamp and that the loop has an opposite locking end for being inserted into the buckle, wherein a deformation area, which is curved in the open state of the pipe clamp, is disposed between the two ends (29, 30), wherein the deformation area is elastically and radially deformable by applying a radial force, its curvature being at least partially reduced in the process, the locking end thus being movable away from the end which is connected to the pipe clamp when the deformation area is deformed.