semicylindrical pipe support 16 as of wood or other firm material if desired an upper support not shown may form the central portion of the upper clamshell member lower support 16 has sufficient rigidity to support the weight of the pipe without crushing the lower block or clamshell member has an inner concave semicylindrical upper surface 16 39 of a diameter which corresponds with the outer diameter of pipe p preferably the tracer conduit line t carrying a hot fluid or the like is beneath pipe p surface 16 39 having a recess 16 39 34 at the lowermost portion thereof to receive tracer line t the depth of recess 16 39 34 is basically equal to the diameter of the tracer pipe to support the tracer line in engagement with main conduit pipe p this rigid support member 16 may be made of wood or other rigid material having excellent heat insulating properties such as a rigid polymeric foam if support portion 16 is made of foam it preferably has an insert dowel of wood or other rigid nonheat conducting material at the bottom thereof for receiving a threaded fastener such as a screw in a manner and for reasons to be explained hereinafter inner surface 16 39 forms part of a cylinder the outer surface of component 16 forms a portion of a larger diameter cylinder and extending 180 u00b0 in an arc swept from the axial centerline of the assembly.